Universal precursors of nanoscale morphology

Abstract

The present disclosure relates to metal coordination polymers. In particular, the present disclosure relates to layered metal coordination polymers that can be used as precursors to form nanostructures of various morphologies and compositions. The present disclosure also relates to metal-based nanostructures that can be prepared from the metal coordination polymers. The nanostructures can have various catalytic properties.

Description

[Technical Field]

[0001] Cross-reference of related applications This application claims priority to Australian Provisional Patent Application No. 2019904036, filed on 25 October 2019, the entire contents of which are incorporated herein by reference.

[0002] This disclosure relates to metal coordination polymers. In particular, this disclosure relates to layered metal coordination polymers that can be used as precursors to form nanostructures of various morphologies and compositions. This disclosure also relates to metal-based nanostructures that can be prepared from metal coordination polymers. [Background technology]

[0003] Two-dimensional structures (e.g., sheets containing nanosheets) have established a new level of functionality for materials, particularly in energy and environmental applications. Minimizing the transverse charge carrier diffusion distance is achieved by reducing the sheet thickness. However, the reduction in sheet thickness is limited to the extent that the sheet's structure and chemistry can dictate the sheet thickness.

[0004] Another method to minimize charge carrier diffusion is to reduce the lateral distance of the sheet, for example, by introducing pores. The formation of pores in nanosheets increases the density of accessible active sites, thereby shortening the distance of lateral charge carrier diffusion. However, to minimize the transverse dispersion distance in porous two-dimensional materials, sheets with atomic-range thicknesses should be achieved. Furthermore, to retain highly active sheets, polycrystalline two-dimensional planar materials are desirable to prevent irreversible re-stacking of nanosheets. However, the synthesis of polycrystalline porous two-dimensional sheets by either top-down or bottom-up strategies remains largely unknown for most compounds.

[0005] The production of porous two-dimensional graphene and porous two-dimensional transition metal chalcogenides (TMCs) and selenides (TMSs) has been reported. However, the processing is relatively complex and requires further steps such as surfactants, sacrificial templates, and / or high-temperature removal of the templates, ultimately resulting in nanosheet thicknesses of tens of nanometers. However, to date, there is little information on the effective synthesis of porous two-dimensional metal oxides (MOs).

[0006] Where any prior art publication is referenced herein, it is understood that such reference does not imply that such publication constitutes part of the general knowledge in the art in Australia or any other country. Summary of the Invention

[0007] The inventors have conducted research and developed metal coordination polymers that can be used to fabricate various metal-based nanostructures, including porous metal oxide nanosheets. In particular, as described herein, metal coordination polymers are inherently unstable and contain reactive metal centers, which can be stabilized by the presence of one or more organic linkers. When used as a precursor, removal of the organic linkers generates highly reactive metal-based substructures, which can then be used to form various stable nanostructures, enabling a tailored and unique process for preparing nanostructures with altered morphologies.

[0008] Metal-coordinate polymers can be layered metal-coordinate polymers. Layered metal-coordinate polymers may comprise two or more layers. Each layer of the metal-coordinate polymer contains a metal atom coordinated to one or more organic linkers to form a metal-coordinate polymer layer. Two or more of these metal-coordinate polymer layers can interact electrostatically to form a layered metal-coordinate polymer. Electrostatic interactions can form between the metal-coordinate polymer layers. The organic linkers include a metallic bond moiety, which can form a coordination bond with a metal atom to form a metal-coordinate polymer layer. The organic linkers also include one or more moieties for forming a layered metal-coordinate polymer by forming electrostatic interactions with adjacent metal-coordinate polymer layers. One or more moieties may be substituted on optionally interrupted alkyl, alkenyl, or alkynyl groups, and / or directly on the metallic bond moiety. Metal-coordinate polymers can also be reaction products of organic linkers and a source of metal atoms.

[0009] In one embodiment, a layered metal coordination polymer comprising two or more layers, Each layer contains metal atoms coordinated to an organic linker in order to form a metal-coordinate polymer layer; where the organic linker is defined by formula 1: XR 1 (1) Selected from one or more compounds having the structure, During the ceremony: X is the metallic bonding portion that coordinates to the metal atom; and R 1 The present invention provides a layered metal coordination polymer, wherein H, or one or more optionally interrupted alkyl, alkenyl, or alkynyl groups substituted with adjacent metal coordination polymer layers to form the layered metal coordination polymer.

[0010] In another embodiment, a layered metal coordination polymer is a reaction product of an organolinker and a source of metal atoms, A layered metal-coordinate polymer comprises two or more layers, each layer containing metal atoms coordinated to an organic linker to form a metal-coordinate polymer layer; In the formula, the organic linker is given by formula 1: XR1 (1) Selected from one or more compounds having the structure, During the ceremony: X is the metallic bonding portion that coordinates to the metal atom; and R 1 The present invention provides a layered metal coordination polymer, wherein H, or one or more optionally interrupted alkyl, alkenyl, or alkynyl groups substituted with adjacent metal coordination polymer layers to form a layered metal coordination polymer.

[0011] In another embodiment, a process for preparing a layered metal-coordinate polymer comprising two or more metal-coordinate polymer layers, as defined above, The process involves combining a metal atom source with an organic linker to form a layered metal-coordinate polymer containing two or more metal-coordinate polymer layers that are held together by electrostatic interactions. It provides a process that includes this.

[0012] In another embodiment, a process for preparing a layered metal-coordinate polymer comprising two or more metal-coordinate polymer layers, as defined above, Mixing an aqueous solution containing a metal atom source and an organic linker to form a layered metal coordination polymer containing two or more metal coordination polymer layers that are held together by electrostatic interaction. It provides a process that includes this.

[0013] In another embodiment, a method for forming nanostructures, To provide a layered metal coordination polymer comprising two or more layers, each layer containing a metal atom coordinated to one or more organic linkers in order to form a metal coordination polymer, and To remove at least a portion of the coordinating organic linker and form a nanostructure. This provides a method that includes [something].

[0014] In another embodiment, a nanostructure prepared using the method defined above is provided.

[0015] In another embodiment, a porous metal oxide nanosheet is provided. The porous metal oxide nanosheet may have a thickness of about 1 nm to about 100 nm.

[0016] In another embodiment, a catalyst composition comprising the nanostructure defined above is provided.

[0017] In another embodiment, the use of the nanostructure defined above as a catalyst is provided.

[0018] It should be understood that one or more of the embodiments and examples described herein for metal coordination polymers may also be applicable to processes for preparing metal coordination polymers, methods for preparing nanostructures described herein, nanostructures described herein, and / or catalyst compositions described herein. Any embodiment described herein should be construed as applicable to any other embodiment, with necessary modifications, unless otherwise specifically stated. It should also be understood that other aspects, embodiments, and examples of metal coordination polymers and nanostructures are described herein.

[0019] As described herein, some features of metal coordination polymers, processes for preparing metal coordination polymers, nanostructures, and methods for preparing nanostructures, identified in certain aspects, embodiments, or examples, are not required in all aspects, embodiments, or examples as described herein, and it should be understood that this application should be read in this context. It should also be understood that the order of methods or process steps is not essential and can be changed in various aspects, embodiments, or examples.

[0020] Embodiments of the present disclosure are described further below, only as examples, with reference to the accompanying drawings where applicable. [Brief explanation of the drawing]

[0021] [Figure 1]This shows the exfoliation and conversion of Ce coordination polymer (CP) nanotubes to porous two-dimensional CeO2-x nanostructures: a-c) Schematic diagram of the Ce-CP hexagonal system, taken by exsitu SEM and TEM; d-f) Schematic diagram of Ce-CP nanosheets obtained by exfoliation of Ce-CP hexagonal nanotubes, taken by exsitu SEM and TEM for 4 minutes at room temperature; g-i) Schematic diagram of Ce-CP nanosheets obtained by exfoliation of Ce-CP hexagonal nanotubes, taken by exsitu SEM and TEM for 8 minutes at room temperature; j-l) Schematic diagram of porous CeO2-x nanosheets obtained by exfoliation of Ce-CP hexagonal nanotubes, taken by exsitu SEM and TEM in a basic aqueous solution (pH=8) for 15 minutes at room temperature; m) Schematic diagram of the layered structure of Ce-CP; n) Ce-CP exfoliated nanosheets as a result of water molecule penetration between stacked Ce-CP nanosheets; and o) Defective CeO2-x nanosheets. The blue, green, red, brown, and black spheres represent cerium, chlorine, oxygen, carbon, and hydrogen ions, respectively. The voids within the defective CeO2-x nanosheets represent oxygen vacancies. [Figure 1A] A schematic diagram of the layered structure of Ce-CP is shown. Large yellow spheres = Ce4+, small green spheres = C4+, small black spheres = H+, small blue spheres = O2-, small red spheres = Cl-. [Figure 2] Defect and structural analysis of porous CeO2-x nanosheets are shown: a, b) Low magnification HAADF images of CeO2-x nanosheets; c) High magnification HAADF images of CeO2-x nanosheets showing nanopores of approximately 2-5 nm transverse size; d) EELS spectra from intercrystalline regions in CeO2-x nanosheets; e) EELS spectra from within CeO2-x crystallites; and f) High magnification HAADF images showing Ce vacancies within CeO2-x crystallites. [Figure 3]Characterization of porous metal oxide (MO) nanosheets is shown: a) TEM images of CeO2-x nanosheets, b) TiO2-x nanosheets, c) ZrO2-x nanosheets; d) corresponding SAED patterns of CeO2-x nanosheets, e) TiO2-x nanosheets, f) ZrO2-x nanosheets; g) AFM images of CeO2-x nanosheets, h) TiO2-x nanosheets, i) ZrO2-x nanosheets; and j) corresponding height profiles of CeO2-x nanosheets, k) TiO2-x nanosheets, l) ZrO2-x nanosheets. [Figure 4] Characterization of transition metal oxides (TMOs) in 0D / 2D heterostructures is shown: a-c) EDS mapping of the 0D / 2D heterostructures of Fe2O3-functionalized CeO2-x nanosheets (FCO), NiO-functionalized CeO2-x nanosheets (NCO), and ZnO-functionalized CeO2-x nanosheets (ZCO); d-f) Laser Raman microspectras of the 0D / 2D heterostructures of FCO, NCO, and ZCO; and g-i) XRD patterns of the 0D / 2D heterostructures of FCO, NCO, and ZCO. [Figure 5] This shows the band structure characterization of CeO2-x and 0D / 2-dimensional heterostructures: a) Topography of CeO2-x porous nanosheets; b) Contact potential difference of CeO2-x porous nanosheets measured by KPFM; c) XPS valence band plot of CeO2-x porous nanosheets; d) Tauc plot from UV-Vis spectrophotometric data of CeO2-x porous nanosheets (Tauc plot model (αhν)=A(hν-Eg)). 2) Applied, where A and α are the absorption and absorption coefficient, respectively; hν is the photon energy, and Eg is the optical indirect band gap); e) Electronic energy level diagram of CeO2-x porous nanosheets and 0D / 2-dimensional heterostructures; f) First-principles DFT calculation of electronic density of states and band gap of CeO2 nanosheets and bulk CeO2; and g) First-principles DFT calculation of electronic density of states and band gap of 0D / 2-dimensional heterostructures. [Figure 6]This shows the formation mechanism of Ce-CP tubes by constant-current electrochemical deposition. a) Current-deposition time plot; b~f) SEM images representing the nucleation / growth process of Ce-CP tubes as a function of electrodeposition time. [Figure 7] A Poole-Bay diagram is shown illustrating the thermodynamic study of the aqueous tetracomponent system Ce(III)-Ce(IV)-trichloroacetic acid (TCA)-H2O as a function of pH. [Figure 8] The experimental X-ray diffraction pattern of Ce-CP is shown. [Figure 9] The neutron diffraction patterns of Ce-CP obtained at wavelengths of 1.63 Å and 2.41 Å are shown. [Figure 10] This image shows a SEM image of a Ce-CP tube grown on an FTO substrate. [Figure 10A] This shows: a) a low-magnification TEM image of a single Ce-CP tube, b) SAED pattern of the region shown in the yellow box, and c) HRTEM image of the region shown in the red box. [Figure 11] The Raman spectra of Ce-CP tube (top) and trichloroacetic acid (bottom) are shown. [Figure 11A] The Raman spectra of CeO2 (top), Ce-CP tube (middle), and trichloroacetic acid (bottom) are shown. [Figure 12] The FTIR spectrum of a Ce-CP tube is shown. [Figure 13] XPS data of a Ce-CP tube is shown. [Figure 14] The TGA analysis of Ce-CP in nitrogen (top) and air (bottom) atmospheres is shown. [Figure 15] This shows the Rietveld refined X-ray diffraction pattern of Ce-CP. [Figure 16] The Rietveld refined ND patterns of Ce-CP at wavelengths of 1.63 Å (bottom) and 2.41 Å (top) are shown. [Figure 17] A schematic diagram of the refined structure derived from XRD and ND data is shown. [Figure 18A]This shows the relaxation structure of the smallest possible Ce-CP unit cell, used as a building block to construct a more representative structural model. [Figure 18B] (a) Shows relaxed Ce-CP corresponding to the structural experimental lattice parameters. All TCA molecules were found to remain intact. A, B, and C show the TCA molecule, water molecule, and Ce ion bound to the OH group, respectively. (b-e) Site-projected partial densities of states of labeled Ce ions and labeled O ions derived from distinct coordination ligands. [Figure 19] Comparison of X-ray diffraction patterns of experimental, Rietveld refined, and early MD-simulated structures. [Figure 20] This shows the structural and morphological evolution from Ce-CP hexagonal nanotubes to CeO2-x nanosheets: a) SEM image of Ce-CP hexagonal nanotubes; b) TEM image of Ce-CP hexagonal nanotubes (inserted: SAED pattern); c) XRD pattern of Ce-CP hexagonal nanotubes; d) SEM image of Ce-CP nanosheets; e) TEM image of Ce-CP nanosheets (inserted: SAED pattern); f) XRD pattern of Ce-CP nanosheets; g) SEM image of porous CeO2-x nanosheets; h) TEM image of porous CeO2-x nanosheets (inserted: SAED pattern); i) XRD pattern of CeO2-x nanosheets. [Figure 21] a) TEM image of Ce-CP nanosheet, b) EDS elemental mapping images of cerium (red), c) oxygen (green), d) chlorine (dark blue), and e) carbon (light blue), and f) EDS spectrum of Ce-CP nanosheet are shown. [Figure 22] a, b) Bright-field TEM images of CeO2-x porous nanosheets, c) EDS elemental mapping images of oxygen (green), d) cerium (red), and e) EDS spectra of CeO2-x porous nanosheets are shown. [Figure 23] The Raman spectra of the CeO2-x nanosheets compared to those of the original Ce-CP are shown, indicating no significant difference. [Figure 24] The image shows an SEM image of Ti-CP. [Figure 25] SEM images of Ti-CP are shown. b) EDS elemental mapping images of titanium, c) oxygen, and d) carbon, e) overlay of the EDS image of Ti-CP, f) corresponding EDS spectrum. [Figure 26] The Raman spectrum of Ti-CP is shown. [Figure 27] The SEM image of Zr-CP is shown. [Figure 28] The image shows: a) SEM image of Zr-CP, b) EDS elemental mapping images of zirconium, c) oxygen, and d) carbon, e) overlay of the EDS image of Zr-CP, and f) corresponding EDS spectrum. [Figure 29] The Raman spectrum of Zr-CP is shown. [Figure 30] a-c) TEM images of ultrathin Ti-CP nanosheets that peel off in DI water at room temperature are shown. [Figure 31] a-c) TEM images of ultrathin porous TiO2 nanosheets are shown, along with d) the corresponding SAED patterns of the TiO2 nanosheets. [Figure 32] The Raman spectrum of a TiO2 nanosheet (black) and the corresponding fittings of the vibrational modes of the anatase (blue) and rutile (red) phases are shown. [Figure 33] XPS results of the carbon 1s orbital in both Ti-CP and TiO2 nanostructures are shown. [Figure 34] XPS results of oxygen 1s orbitals in both Ti-CP and TiO2 nanostructures are shown. [Figure 35] TEM images showing the detachment of bulk Zr-CP in DI water at room temperature and the formation of self-supporting Zr-CP nanosheets are shown. [Figure 36] a-c) TEM images of ultrathin porous ZrO2 nanosheets obtained by exfoliating Zr-CP in DI water at room temperature, and d) SAED patterns of the ZrO2 nanosheets revealing the polycrystalline nature of the nanosheets. [Figure 37] The Raman spectrum of zirconia oxide nanosheets (black) and the corresponding fittings of the vibrational modes of the monoclinic (blue) and cubic (red) phases are shown. [Figure 38] XPS results of the carbon 1s orbital in both Zr-CP and ZrO2 nanostructures are shown. [Figure 39] XPS results of the carbon 1s orbital in both Zr-CP and ZrO2 nanostructures are shown. [Figure 40] XPS results of cerium 3d orbitals and oxygen 1s orbitals in porous CeO2-x nanostructures are shown. [Figure 41] This shows the zeta potential of CeO2-x in DI water. [Figure 42] The speciation diagrams for a) Fe(II), b) Ni(II), and c) Zn(II) species are shown as functions of pH in aqueous solutions, representing species stability and changes in species concentration. [Figure 43] The following images are shown: d) TEM and HRTEM images of FCO; e-g) SAED pattern of FCO; h) SAED pattern of NCO; i-k) TEM and HRTEM images of ZCO; l) SAED pattern of ZCO. [Figure 44] a) XPS valence measurements of porous CeO2-x nanosheets, b) FCO, c) NCO, and d) ZCO are shown. [Figure 45] a) Tauc plots for porous CeO2-x nanosheets, b) FCO, c) NCO, and d) ZCO are shown. [Figure 46] The photoluminescence spectra of CeO2-x, FCO, NCO, and ZCO are shown. [Figure 47] a) Decomposition of methylene blue (MB) in the presence of porous nanosheets (blue bars) and porous nanosheets with NiO (purple) and Fe2O3 (green) attached; b) Reaction kinetics of MB decomposition; c) Comparison table of the as-synthesized sample and recently reported results of MB decomposition; d) Overview of the MB decomposition performance of the CeO2-x structure. [Figure 48] TEM and SEM micrographs of CeO2-x nanostructures derived from Ce-CP are shown (scale bars: yellow = 3 μm, red = 100 nm). For f and h, low-magnification TEM images are shown instead of SEM images due to the small size of the cubic and dumbbell-shaped morphologies. [Figure 49] a) A three-electrode electrochemical cell used for the synthesis of CeO2-x tubes under vigorous oxygen evolution and deposition of self-supporting hexagonal CeO2-CP tubes on a fluorine-doped tin oxide (FTO) substrate; b) A schematic diagram of the three-step process of CeO2-x formation, including exfoliation from CeO2-CP tubes to CeO2-CP nanosheets and subsequent oxidation from CeO2-CP nanosheets to porous CeO2-x nanosheets. [Figure 50] a) Chronopotentiometric electrodeposition of solid Ce-CP hexagonal rods under electrolytic conditions; b) Decomposition of Ce-CP hexagonal rods and recrystallization from Ce-CP to hollow pseudo-octahedrons; c) Simplified molecular structure of hexagonal Ce-CP rods; d) Schematic diagram of solute in ethanol solution; e) Corresponding molecular structure; f) Schematic diagram of recrystallized Ce-CP; g) Schematic diagram of the corresponding molecular structure. Large yellow sphere = Ce4+, small green sphere = C4+, small blue sphere = O2, small red sphere = Cl-. [Figure 51] (a, b) SEM and (c, d) TEM images of the Ce-CP structure are shown (the insets show the SAED patterns, respectively). [Figure 52] (a) Experimental X-ray diffraction patterns obtained from a newly prepared Ce-CP and (b) from a sample aged for 3 months (under ambient conditions) are shown. [Figure 53] (a) Formation of Ce-CP monolayers at the ethanol / air interface: Ce4+ (green), -OH group of ethanol (purple), -COO- group of TCA (blue), and -CCl3 group of TCA (red), b) Monolayer and stacked configurations (residues -OH and H2O are omitted from Ce-CP and solution volume for simplicity), c) Optical microscope image of Ce-CP nanosheet, d) AFM image of Ce-CP nanosheet and index corresponding to height profile, e) Low magnification TEM image of Ce-CP nanosheet; Insert: SAED pattern of Ce-CP nanosheet, schematic diagram of EDS mapping of Ce-CP nanosheet showing the map of f~k)(g)Ce;h)O;i)Cl;j)C;k)Sn. [Figure 54]AFM images and corresponding height profiles of Ce-CP nanosheets printed from the surface of ethanol are shown for evaporation times of a) 12 hours, b) 24 hours, c) 36 hours, d) 48 hours, and e) 72 hours. [Figure 55] a, b) 4M, c, d) 8M. These images show AFM images and corresponding height profiles of Ce-CP nanosheets printed from the surface of ethanol. [Figure 56] a, b) HAADF images and (b, inset) SAED images of porous CeO2-x nanosheets, c) HRTEM image of porous CeO2-x nanosheets, d) XPS spectrum of Ce 3d orbitals of Ce within porous CeO2-x nanosheets, e) AFM image of porous CeO2-x nanosheets, f) AFM height profile of CeO2-x nanosheets. [Figure 57] a) SEM image, b) schematic diagram of recrystallized Ce-CP, c) corresponding XRD pattern, d) SEM image, e) schematic diagram of NaOH-aged CeO2-x pseudooctahedron, f) corresponding XRD pattern, g) SEM image, h) schematic diagram of CeO2-x pseudooctahedron, i) corresponding XRD pattern, j) dark-field TEM and SAED (insertion), k) dark-field HRTEM image of CeO2-x pseudooctahedron. [Figure 58] (a) XRD patterns of a Ce-CP rod (black) synthesized by electrochemical deposition and a Ce-CP octahedron (red) obtained by decomposition / recrystallization in ethanol; b) HRTEM images of the Ce-CP rod (left) and Ce-CP octahedron (regions enclosed by yellow solid lines indicate single crystals); c) Raman spectra of the Ce-CP rod (black) and Ce-CP octahedron (red); d) FTIR spectra of the Ce-CP rod (black) and Ce-CP octahedron (red). [Figure 59]SEM images of Ce-CP morphology synthesized at 0°C: a) [Ce-CP]=4M, b) [Ce-CP]=16M, c) hollow spheres released from nanosheets, d) schematic diagram showing the formation of Ce-CP hollow spheres via bubbling of stacked nanosheets as a result of ethanol evaporation, e) 3D AFM images of Ce-CP nanosheets synthesized by two-step evaporation at -10°C (12 hours) and 15°C (0.5 hours), f) AFM height profile (black dotted line). [Figure 60] Characterization of hollow CeO2-x spheres: a) Low-magnification SEM image of a hollow CeO2-x sphere, b) High-magnification SEM image of a hollow CeO2-x sphere, c) SEM image of a damaged hollow sphere, d) Low-magnification TEM image of a hollow CeO2-x sphere, e, f) High-magnification TEM image of a hollow CeO2-x sphere, g) SAED pattern of a hollow CeO2-x sphere, h, i) EDS elemental mapping of Ce and O within the hollow CeO2-x sphere, j) Raman spectra of Ce-CP rods before and after NaOH aging and heating at 200°C. [Figure 61] a) SEM images of Ce-CP nanostructures synthesized at 25°C using varying concentrations of Ce-CP (4M, b) 8M, c) 40M, and d) 120M. e-h) SEM images of corresponding CeO2-x nanostructures derived from Ce-CP after aging in NaOH (6M) at 25°C and subsequent heating at 200°C are shown. [Figure 62] SEM, TEM, and HRTEM images, as well as SAED patterns of CeO2-x derived from Ce-CP morphology synthesized at 25°C, are shown: a-c) 5 mM, d-f) 10 mM, g-i) 50 mM, and j-l) 100 mM. [Figure 63] This shows the formation mechanism of Ce-CP nanostructures. [Figure 64] a) CO conversion rates and TOF values ​​obtained by using different nanostructure morphologies of CeO2-x, and b) Arrhenius plots for CO oxidation across samples are shown. [Figure 65] XPS Ce 3d spectra of porous nanosheets, hollow octahedra, hollow spheres, and exfoliated CeO2-x are shown. [Figure 66]XPS Ce 3d spectra of porous nanosheets, hollow octahedra, hollow spheres, and exfoliated CeO2-x are shown. [Figure 67] Photocatalytic performance of CeO2-x morphology: a) UV-Vis absorption spectra of MB dye solutions after 160 minutes of irradiation for different morphologies, b) 664 nm peak intensity based on UV-Vis absorption spectra of MB dye solutions at different irradiation times for different morphologies, c) plots of absorbance (At / A0, time t vs. initial time) and dye degradation as a function of irradiation time of porous nanosheets, d) comparison of the photocatalytic performance obtained in this work with that of prior art under similar test conditions. [Figure 68] This paper demonstrates the effects of morphological structure and physical properties on the catalytic and photocatalytic performance of these catalysts. [Figure 69] This shows the zeta potential of layered Ce-CP in DI water. [Figure 70] Structural analysis: a) XRD spectra and b) laser Raman microspectroscopy (all intensities were on the same scale) are shown for Ce-CP nanotubes, reconstructed Ce-CP macrolayers (derived from DMSO, R-Ce-CP), air-burned Ce / S / C, and N2-burned Ce / S / C. [Figure 71] The XPS spectra of a) Cl 2p, b) C 1s, and c) S 2p orbitals for Ce-CP nanotubes (NT), DMSO-derived Ce-CP (T at room temperature), Ce / S / C (air) burned in air, and Ce / S / C (N2) burned in N2 are shown. [Figure 72] The XPS spectra of (a) Ce 3d orbitals and (b) O 1s orbitals of Ce-CP, DMSO-derived Ce-CP, air-burned Ce / S / C, and N2-burned Ce / S / C samples are shown. [Figure 73] The EPR analysis of Ce / S / C and CeO2 in its original state is shown. [Figure 74] The XRD patterns of the polycrystalline octahedral nanostructures are shown in comparison to those of the original Ce-CP. [Figure 75]a) HAADF-STEM images and EELS-STEM maps of Ce-OS samples are shown. The maps were obtained by extracting the SK edge signal at 165 eV (green), the CK edge signal at 284 eV (yellow), the OK edge at 532 eV (blue), and the CeM edge at 883 eV (red). b) The CeM5 / M4 ratio for evaluating the cerium oxidation state distribution is also reported, along with a color legend. c) Normalized EELS spectra of the CK edge peak and d) CeM edge peak. The scale bar is 100 nm. [Figure 76] HRTEM images from the sample are shown along with the corresponding indexed power spectra and frequency-filtered maps highlighting different crystals. [Figure 77] a) A schematic diagram of the two-step process of exfoliating Ce-CP nanotubes in a stirred TEA solution and oxidizing them in air at 450°C to form a stacked CeO2-x macrolayer. b-e) The morphology of CeO2-x derived from Ce-CP is shown. [Figure 78] SEM images of CeO2-x obtained at 450°C at different heating rates: a) slow combustion at 0.2°C min⁻¹, b) medium combustion at 1.0°C min⁻¹, c) fast combustion at 2.0°C min⁻¹, and d) fast combustion at 3.0°C min⁻¹. [Figure 79] a-c) SEM images of hybrid 2D-3D CeO2-x, d) HRTEM images and SAED (with pore contours) of porous 2D CeO2-x nanosheets, e) EDS elemental mapping of porous 2D CeO2-x nanosheets, f) AFM images of porous 2D CeO2-x nanosheets (step height indicated by white dotted lines) and corresponding height profiles are shown. [Figure 80] a) TEM and b) HRTEM images of porous Mn-Ce nanosheets, c) SAED patterns of porous Mn-Ce nanosheets, d) STEM elemental mapping of O, Mn, and Ce within porous Mn-Ce nanosheets, and e) STEM line scans across porous Mn-Ce nanosheets are shown. [Figure 81]The XRD spectra of 2D-3D CeO2-x, Mn-Ce, and Cu-Ce are shown (α-MnO2 is indicated by the Miller indices within Mn-Ce). [Figure 82] a) CO oxidation plots for Ce-NT, CeO2-x, Mn-Ce, and Cu-Ce; b) comparative CO oxidation data for CeO2-x and CeO2-x-based hybrids; c) Mechanism 1: CO oxidation reaction pathway due to initial O2 adsorption estimated from first-principles calculations based on DFT; d) Energy profile calculated for Mechanism 1; e) Mechanism 2: CO oxidation reaction pathway due to initial CO adsorption estimated from first-principles DFT calculations; f) Energy profile calculated for Mechanism 2. Embodiments for carrying out the present invention

[0022] General terminology In the following description, several embodiments are illustrated by reference to the accompanying drawings which form part of this specification. It will be understood that other embodiments may be utilized, and structural variations may be made without departing from the scope of this disclosure.

[0023] With respect to the definitions provided herein, unless otherwise stated or implied by the context, defined terms and phrases include the meanings provided. Unless expressly stated or evident from the context, the following terms and phrases do not exclude the meanings obtained by those skilled in the art in which the term or phrase relates. For example, all technical and scientific terms used herein should be interpreted as having the same meaning as commonly understood by those skilled in the art in which they relate (e.g., materials science, inorganic chemistry, polymer chemistry, and nanotechnology). The definitions are provided to aid in describing specific embodiments and are not intended to limit the invention described in the claims, for the scope of the invention is limited only by the claims. Furthermore, unless otherwise required by the context, singular forms include plural forms and plural forms include singular forms.

[0024] All publications discussed and / or referenced herein are incorporated herein in their entirety.

[0025] Any consideration of documents, regulations, materials, apparatus, articles, etc., included herein is solely for the purpose of providing context for the present invention. It shall not be acknowledged that any or all of these matters form part of the foundation of the prior art or were common knowledge in the art relating to this disclosure as existed prior to the priority date of each claim of this application.

[0026] Throughout this disclosure, unless otherwise specifically stated or required by the context, a single process, composition of a material, group of processes, or group of compositions of a material should be interpreted as encompassing one and more (i.e., one or more) such processes, compositions of a material, group of processes, or group of compositions of a material. Accordingly, as used herein, the singular forms "a," "an," and "the" include multiple aspects unless the context clearly specifies otherwise. For example, a reference to "a" includes one and more than one; a reference to "an" includes one and more than one; a reference to "the" includes one and more than one, and so on.

[0027] Those skilled in the art will recognize that this disclosure is susceptible to variations and modifications other than those specifically described herein. It should be understood that this disclosure includes all such variations and modifications. Furthermore, this disclosure includes, individually or collectively, all examples, processes, features, methods, compositions, coatings, processes, and coating substrates, as well as any and all or any two or more of such processes or features.

[0028] The terms “and / or,” for example, “X and / or Y,” shall be understood to mean either “X and Y” or “X or Y,” and shall be construed as providing explicit support for both meanings or either meaning. Where used in this application, the terms “or” are intended to mean inclusive “or,” rather than exclusive “or.” That is, unless otherwise indicated or evident from the context, “X adopts A or B” is intended to mean either of the original inclusive substitutions. That is, if X adopts A, X adopts B, or X adopts both A and B, then “X adopts A or B” is satisfied in any of the above cases. Furthermore, at least one of A and B and / or similar generally means A or B, or both A and B. In addition, the articles “a” and “an,” where used in this application and the attached claims, may generally be construed to mean “one or more,” unless otherwise specified or evident from the context toward the singular form.

[0029] Unless otherwise specified, terms such as “first,” “second,” and “further” are used herein solely as indicators and are not intended to impose any requirements for order, position, or hierarchy in the items referred to by these terms. Furthermore, a reference to an item “second” does not require or exclude the presence of items with lower numbers (e.g., an item “first”) and / or items with higher numbers (e.g., an item “third”).

[0030] As used herein, the phrase “at least one of” when used in reference to an item listing means that one or more different combinations of the listed items may be used, and only one of the items in the listing may be required. An item can be a specific object, matter, or category. In other words, “at least one of” means any combination of items, or the number of items may be used from the listing, but not all items in the listing are required. For example, “at least one of item A, item B, and item C” may mean item A; item A and item B; item B; item A, item B, and item C; or item B and item C. In some cases, “at least one of item A, item B, and item C” may mean, for example, two item A, one item B, and ten item C; four item B and seven item C; or several other preferred combinations.

[0031] As used herein, the term “about” typically refers to a range of + / - 10% of a given value, for example, + / - 5%, unless otherwise specified.

[0032] It should be understood that certain features described herein in the context of separate embodiments may be provided in combination in a single embodiment. Conversely, for the sake of brevity, various features described in the context of a single embodiment may be provided separately or in any partial combination.

[0033] Throughout this specification, various aspects and components of the invention may be presented in the form of ranges. These ranges are included for convenience and should not be interpreted as inflexible limitations on the scope of the invention. Therefore, a range description should be considered to specifically disclose all possible subranges and individual numerical values ​​within those ranges unless specifically indicated otherwise. For example, a range description such as 1–5 should be considered to specifically disclose subranges such as 1–3, 1–4, 1–5, 2–4, 2–5, 3–5, and individual and partial digits within the enumerated range, e.g., 1, 2, 3, 4, 5.5, and 6, unless an integer is required or implied by the context. This applies regardless of the width of the disclosed range. Where specific values ​​are required, they will be provided herein.

[0034] Throughout this specification, variations of the word such as “comprise,” “comprises,” or “comprising” will be understood to imply the inclusion of the element, integer, or process, or group of elements, integers, or processes, being referred to, but not to imply the exclusion of any other element, integer, or process, or group of elements, integers, or processes.

[0035] Variations of the term "consists of" or "consisting of" indicate the inclusion of any element, integer, or process, or group of elements, integers, or processes, that are cited in the context of this term, and exclude any other element, integer, or process, or group of elements, integers, or processes that are not cited in the context of this term.

[0036] Specific terminology The following definitions apply to terms used throughout this specification, unless otherwise specifically limited.

[0037] The term "organolinker" refers to a compound that can form one or more coordination bonds with one or more metal atoms.

[0038] The term "metallic ligand moiety" refers to a chemical moiety capable of coordinating (e.g., bonding) to a metal. Non-limiting examples of metallic ligand moieties include -COOH, -OH, -NH2, -SH, and -CN.

[0039] The term “optionally substituted” means that the functional group is either substituted or unsubstituted at any available position. “Unsubstituted” should be understood to refer to a hydrogen group. A substitution may have one or more heteroatoms, including one or more O, N, S, Se, Te, Si, and / or one or more functional groups selected from one or more alkenyl, alkynyl, aryl, heteroaryl, heteroaryl, and / or cycloalkyl groups, where each alkenyl, alkynyl, aryl, heteroaryl, or cycloalkyl group is as defined herein.

[0040] "Alkyl," whether used alone or in compound words such as alkoxy, alkylthio, alkylamino, dialkylamino, or haloalkyl, refers to a linear or branched hydrocarbon with a size range of 1 to about 20 or more carbon atoms. Therefore, unless explicitly limited, alkyl moieties include, for example, small groups or moieties with a size range of 1 to about 6 or more carbon atoms, such as methyl, ethyl, n-propyl, isopropyl, and / or butyl, pentyl, hexyl, as well as higher-order isomers, such as linear or branched hydrocarbons with a size range of about 6 to about 20 or more carbon atoms. 1-20 Alkyl," "C 1-10 "Alkyl" and "C 1-6 "Alkyl" refers to a specific alkyl chain length, as described herein.

[0041] Whether used alone or in compound terms such as alkenyloxy or haloalkenyl, "alkenyl" refers to a linear or branched hydrocarbon containing at least one carbon-carbon double bond, and unless expressly limited, includes, for example, small groups and moieties within a size range of 2 to about 6 or more carbon atoms, such as ethylene, 1-propenyl, 2-propenyl, and / or butenyl, pentenyl, hexenyl, and higher isomers, such as linear or branched hydrocarbons within a size range of about 6 to about 10 or more carbon atoms.

[0042] "Alkynyl," whether used alone or in compound words such as alkynyloxy, refers to a linear or branched hydrocarbon containing at least one carbon-carbon triple bond, and unless expressly limited, includes, for example, small groups and moieties within a size range of 2 to about 6 or more carbon atoms, such as ethynyl, 1-propynyl, 2-propynyl, and / or butynyl, pentynyl, hexynyl, and higher isomers, such as linear or branched hydrocarbons within a size range of about 6 to about 10 or more carbon atoms.

[0043] "Cycloalkyl" refers to monocyclic or polycyclic carbocyclic systems of varying sizes, such as cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, or cycloheptyl, with approximately 3 to 10 carbon atoms. The term "cycloalkyloxy" refers to the same group linked through one oxygen atom, such as cyclopentyloxy and cyclohexyloxy. The term "cycloalkylthio" refers to the same group linked through one sulfur atom, such as cyclopentylthio and cyclohexylthio.

[0044] "Aryl," whether used alone or in compound words such as arylalkyl, aryloxy, or arylthio, refers to (i) an optionally substituted monocyclic or polycyclic aromatic carbocyclic moiety of about 6 to about 60 carbon atoms, such as phenyl, naphthyl, or fluorenyl; or (ii) an optionally substituted partially saturated polycyclic aromatic carbocyclic system in which an aryl and a cycloalkyl or cycloalkenyl group are condensed together to form a cyclic structure, such as tetrahydronaphthyl, indenyl, indanyl, or fluorene ring.

[0045] "Heterocyclyl" or "heterocyclic" can be used alone or in compound terms such as heterocyclyloxy to refer to (i) an optionally substituted cycloalkyl or cycloalkenyl group having about 3 to about 60 ring members, which may contain one or more heteroatoms such as nitrogen, oxygen, or sulfur (examples include pyrrolidinyl, morpholino, thiomorpholino, or fully or partially hydrogenated thienyl, furyl, pyrrolyl, thiazolyl, oxazolyl, oxazinyl, thiadinyl, pyridyl, and azepinyl); (ii) an optionally substituted partially saturated polycyclic ring system in which an aryl (or heteroaryl) ring and a heterocyclic group are condensed together to form a cyclic structure (examples include chromanyl, dihydrobenzofuryl, and indolinyl); or (iii) an optionally substituted fully or partially saturated polycyclic condensed ring system having one or more bridges (examples include quinuclidinyl and dihydro-1,4-epoxynaphthyl).

[0046] "Heteroaryl," used alone or in compound terms such as heteroaryloxy, refers to (i) an arbitrarily substituted monocyclic or polycyclic aromatic organic moiety of about 1 to about 10 ring members, where one or more ring members are elements other than carbon, e.g., nitrogen, oxygen, sulfur, or silicon; a heteroatom(s) that breaks the carbocyclic ring structure and has a sufficient number of delocalized pi electrons to result in aromaticity, but the ring does not contain adjacent oxygen and / or sulfur atoms. Typical six-membered heteroaryl groups are pyrazinyl, pyridadinyl, pyrazolyl, pyridyl, and pyrimidinyl. All positional isomers are conceived, e.g., 2-pyridyl, 3-pyridyl, and 4-pyridyl. Typical five-membered heteroaryl rings are furyl, imidazolyl, oxazolyl, isoxazolyl, isothiazolyl, oxadiazolyl, pyrrolyl, 1,3,4-thiadiazolyl, thiazolyl, thienyl, triazolyl, and silol. All positional isomers are intended, e.g., 2-thienyl and 3-thienyl. Bicyclic groups are typically benzo-condensed ring systems derived from the heteroaryl groups named above, e.g., benzofuryl, benzimidazolyl, benzothiazolyl, indolyl, indolidinyl, isoquinolyl, quinazolinyl, quinolyl, and benzothienyl; or (ii) optionally substituted partially saturated polycyclic heteroaryl ring systems in which a heteroaryl and a cycloalkyl or cycloalkenyl group are condensed together to form a cyclic structure such as a tetrahydroquinolyl or pyridinyl ring.

[0047] "Carboxyl" represents the -CO2H part. "Carboxylate" represents the -CO2 - They represent parts. The two terms may be used interchangeably, as will be understood by those skilled in the art.

[0048] "Cyano" represents the -CN portion.

[0049] "Hydroxyl" represents the -OH portion.

[0050] "Alkoxy" represents an -O-alkyl group, where the alkyl group is as defined above. Examples include methoxy, ethoxy, n-propoxy, iso-propoxy, and different butoxy, pentoxy, hexyloxy, and higher isomers.

[0051] "Amino" or "amine" represents an -NH2 moiety.

[0052] "Alkylamino" represents an -NHR or -NR2 group, where R is an alkyl group as defined above. Examples include methylamino, ethylamino, n-propylamino, isopropylamino, and different butylamino, pentylamino, hexylamino, and higher isomers, but are not limited thereto.

[0053] "Nitro" represents an -NO2 moiety.

[0054] "Amide" represents a -C(O)NR1R2 moiety.

[0055] "Sulfonyl" represents a -SO2R group linked to the rest of the molecule via a sulfur atom.

[0056] "Sulfonamide" represents a -SO2NR1R2 moiety.

[0057] "Alkylsulfonyl" represents a -SO2-alkyl group, where the alkyl group is as defined above.

[0058] The terms "thiol", "thio", "mercapto" or "mercaptan" refer to any organosulfur group containing a sulfhydryl moiety -SH, which includes an R-SH group, where R is a moiety containing a carbon atom covalently bonded to the -SH moiety and is, for example, an alkylsulfur group as defined above. In one embodiment, the thiol or mercapto group is a sulfhydryl moiety -SH.

[0059] "Alkylthio" represents an -S-alkyl group, where the alkyl group is as defined above. Examples include, but are not limited to, methylthio, ethylthio, n-propylthio, isopropylthio, and different butylthio, pentylthio, hexylthio, and higher isomers.

[0060] "Cyano" or "nitrile" represents the -CN portion.

[0061] The term "halo" or "halogen" refers to fluorine, chlorine, bromine, or iodine, whether used alone or in compound terms such as haloalkyl, haloalkenyl, haloalkynyl, haloalkoxy, or haloalkylsulfonyl. Furthermore, when used in compound terms such as haloalkyl, haloalkenyl, haloalkynyl, haloalkoxy, or haloalkylsulfonyl, the alkyl can be partially halogenated or completely substituted with halogen atoms that may be the same or different independently. Examples of haloalkyl include, but are not limited to, -CH2CH2F, -CF2CF3, and -CH2CHFCl. Examples of haloalkoxy include, but are not limited to, -OCHF2, -OCF3, -OCH2CCl3, -OCH2CF3, and -OCH2CH2CF3. Examples of haloalkylsulfonyl include, but are not limited to, -SO2CF3, -SO2CCl3, -SO2CH2CF3, and -SO2CF2CF3.

[0062] metal coordination polymer This disclosure provides metal-coordinate polymers. Metal-coordinate polymers are organometallic polymer structures containing metal atomic centers linked by linkers / ligands. Metal-coordinate polymers include repeating coordination entities that can extend in one, two, or three directions.

[0063] Metal coordination polymers can be layered metal coordination polymers having ordered regions that provide crystallinity and disordered regions that provide amorphous properties, for example, being at least partially amorphous or at least partially crystalline. Metal coordination polymers can be crystalline or amorphous. In one embodiment, the metal coordination polymer is crystalline, e.g., polycrystalline, and may contain, for example, an appropriate amount of homogeneity. In another embodiment, the metal coordination polymer is amorphous. It should be understood that crystalline (e.g., polycrystalline) metal coordination polymers are void-containing frameworks containing arrangements of metal atoms linked by organic linkers. Amorphous metal coordination polymers retain the basic building blocks and connectivity of their crystalline counterparts but lack any long-range periodic order.

[0064] Metal coordination polymers can have one-dimensional, two-dimensional, or three-dimensional architectures. A metal coordination polymer may comprise two or more two-dimensional metal coordination polymer layers (e.g., a layered metal coordination polymer) or it may be a metal-organic framework (MOF). In some embodiments, the metal coordination polymer is in the form of a two-dimensional sheet. Two or more two-dimensional sheets may interact electrostatically to form a layered metal coordination polymer. The architecture of a metal coordination polymer is generally determined by the metal(s) and ligand(s) used to form the metal coordination polymer.

[0065] One-dimensional architectures should be understood to include, for example, linear structures of metal atoms linked by organic linkers. Two-dimensional architectures should be understood to include, for example, sheet or layer structures having length and width (e.g., area) dimensions of metal atoms linked by organic linkers. Two-dimensional architectures can interact electrostatically to form layered metal-coordinate polymers. Three-dimensional architectures should also be understood to form structures including, for example, spherical or cubic structures having length, width, and height (e.g., volume) dimensions of metal atoms linked by organic ligands.

[0066] In some embodiments, the metal coordination polymer may comprise two or more layers, each extending in two dimensions (i.e., a two-dimensional metal coordination polymer layer). Each metal coordination polymer layer may interact (e.g., via electrostatic interactions) to form a layered metal coordination polymer.

[0067] In one embodiment, a layered metal coordination polymer may comprise at least two layers (e.g., at least two metal coordination polymer layers). A layered metal coordination polymer may be referred to as bulk layered or layered metal coordination polymer. The term "layered" means formed or arranged in layers or hierarchies. A layered metal coordination polymer may comprise at least 2, 3, 4, 5, 10, 12, 15, 20, 25, 50, 75, 100, 125, 150, 200, 300, 400, or 500 layers. A layered metal coordination polymer may have a range of layers provided by any two of these upper and / or lower limit layer counts, e.g., about 2 to 500, or about 10 to 200, or 20 to 100 layers. The number of layers may be measured using scanning electron microscopy.

[0068] When metal coordination polymers form sheets, multiple sheets can be assembled to form layered metal coordination polymers. When forming a layered structure, some of the organic linkers may be sandwiched between adjacent sheets, and in some embodiments, (for example, one or more scattered between the layers) Labile Electrostatic interactions can be formed (through ions).

[0069] It should be understood that layered metal-coordinate polymers can form structures with arbitrary morphologies, including metal-coordinate polymer layers that can be exfoliated into individual metal-coordinate polymer layers. Layered metal-coordinate polymers can also be decomposed and reconstructed in organic solvents, and the morphology of the metal-coordinate polymers can be modified depending on the conditions.

[0070] The layered metal coordination polymer does not have to be planar. In some embodiments, the layered metal coordination polymer may be formed in a tube or rod shape. For example, the layers may wrap around the central axis of the layered metal coordination polymer. Suitable morphologies may include, but are not limited to, sheet-like, hollow, cubic, rod-like, polyhedral, spherical or hemispherical, round or semi-round, angular, and irregular morphologies. For example, the layered metal coordination polymer may form nanotubes with layers (e.g., hexagonal Ce-CP nanotubes) or irregular layered structures. The layered metal coordination polymer forms a structure having an aspect ratio of 1.0 to 100.0, 1.0 to 50.0, or 1.0 to 20.0 (i.e., the ratio of length to width, where the length and width are measured perpendicular to each other and the length refers to the dimension measured as the longest and straightest). The morphology can be determined using scanning or transmission electron microscopy.

[0071] The layered metal coordination polymer may have an average pore diameter. In some embodiments, the average pore diameter of the layered metal coordination polymer can be at least 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 15, 20, 50, 80, or 100 nm. The average pore diameter of the layered metal coordination polymer can be less than 100, 80, 50, 20, 15, 10, 9, 8, 7, 6, 5, 4, 3, 2, or 1 nm. The pore diameter can be in the range provided by any two of these upper and / or lower limits of the average pore diameter, e.g., about 1 nm to about 50 nm or about 5 nm to about 20 nm. The pore diameter can be about 1, 2, 3, 4, 5, 6, 7, 8, 9, or 10 nm.

[0072] The layered metal coordination polymer may have an average pore volume. The pore volume can be at least about 0.01, 0.1, 0.2, 0.5, 0.8, 1.0, 1.2, 1.5, 2, 5, or 10 cm 3 / g. The average pore volume can be about 10, 5, 2, 1.5, 1.2, 1.0, 0.8, 0.5, 0.2, 0.1, or 0.01 cm 3It may be less than / g. The average pore volume is the range provided by any two of these upper and / or lower average pore volumes, for example, about 0.1 to about 2 cm³. 3 It could be / g

[0073] Layered metal-coordinate polymers may have a specific surface area, such as a Brunauer-Emmett-Teller (BET) surface area. The specific surface area may be at least about 25, 50, 75, 85, 95, 100, 200, 500, or 1000 m². 2 It can be / g. The specific surface area is approximately 1000, 500, 200, 100, 95, 85, 75, 50, or 25 m². 2 It may be less than / g. The specific surface area is at least about 70, 75, 80, 85, 90, 95, or 100 m². 2 It can be / g. The specific surface area is within the range provided by any two of these upper and / or lower specific surface area limits, for example, about 75 to about 1000 m². 2 It could be / g

[0074] It should be understood that the average pore size, pore volume, and specific surface area can be modified depending on the metal atoms or organic linkers, reagents, solvents, and reaction conditions used in the preparation of the metal-coordinated polymer layer. The average pore size, pore volume, and specific surface area can be measured by any suitable technique, such as gas sorption or scattering techniques.

[0075] Layered metal-coordinate polymers contain metal atoms coordinated to organic linkers in order to form metal-coordinate polymer layers. The organic linkers of the metal-coordinate polymers include metallic bonding portions and one or more portions that can form electrostatic interactions with adjacent metal-coordinate polymer layers to form layered metal-coordinate polymers.

[0076] Organic linkers are typically selected from compounds containing a metallic bond. In one embodiment, the organic linker is one or more carboxylic acid (-COOH) / carboxylate (-COO -) It can be selected from compounds containing a hydroxyl (-OH), amine (-NH2), nitro (-NO2), thiol (-SH), or nitrile (-CN) group. In addition to the metal-binding moiety, the organic linker can include one or more moieties capable of forming an electrostatic interaction with an adjacent metal coordination polymer layer to form a layered metal coordination polymer.

[0077] In one embodiment, the organic linker can be an optionally interrupted alkyl, alkenyl, or alkynyl substituted with a metal-binding moiety and one or more moieties capable of forming an electrostatic interaction with an adjacent metal coordination polymer layer to form a layered metal coordination polymer. In another embodiment, the organic linker is an optionally interrupted alkyl substituted with a metal-binding moiety and one or more moieties capable of forming an electrostatic interaction with an adjacent metal coordination polymer layer to form a layered metal coordination polymer.

[0078] In one embodiment, the metal coordination polymer includes metal atoms coordinated to the organic linker to form a metal coordination polymer layer, and the metal atoms include one or more metals selected from transition metals, post-transition metals, metalloids, or rare earth metals (including actinides and lanthanides); the organic linker is selected from an optionally interrupted alkyl, alkenyl, or alkynyl substituted with a metal-binding moiety and one or more moieties capable of forming an electrostatic interaction with an adjacent metal coordination polymer layer to form a layered metal coordination polymer. The metal atoms can be provided by any of the embodiments or examples described herein.

[0079] In one embodiment, the organic linker can be selected from compounds containing one or more carboxylic acid (-COOH), hydroxyl (-OH), amine (-NH2), nitro (-NO2), thiol (-SH), or nitrile (-CN) groups, and one or more moieties capable of forming an electrostatic interaction with an adjacent metal coordination polymer layer to form a layered metal coordination polymer. The organic linker can be provided by any of the embodiments or examples described herein.

[0080] Metals used in metal coordination polymers Layered metal-coordinate polymers contain metal atoms coordinated to an organic linker in order to form a metal-coordinate polymer layer. The metal atoms can be any metal atoms suitable for forming a coordination network, for example, capable of forming coordination bonds to the metallic bonding portion.

[0081] In some embodiments, the metal atoms may typically include one or more metals selected from Group 1 to Group 16 metals and rare earth metals (i.e., actinides and lanthanides) of the periodic table.

[0082] In some embodiments, the metal atoms may typically include one or more metals selected from alkali metals, alkaline earth metals, transition metals, post-transition metals, metalloids, or rare earth metals (including actinides and lanthanides). Non-limiting metal atoms are derived from the following groups: alkali metals (e.g., Li, Na, K, Rb, Cs, Fr), alkaline earth metals (e.g., Be, Mg, Ca, Sr, Ba, Ra), transition metals (e.g., Sc, Y, Ti, Zr, Hf, V, Nb, Ta, Cr, Mo, W, Mn, Tc, Re, Fe, Ru, Os, Co, Rh, Ir, Ni, Pd, Pt, Cu, Ag, Au, Zn, Cd, Hg), transition metals Transfer metals (e.g., Al, Ga, In, Tl, Sn, Pb, Bi), metalloids (e.g., B, Si, Ge, As, Sb, Te, Po, P), and rare earth metals (e.g., La, Ce, Pr, Nd, Pm, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, Lu, Ac, Th, Pa, U, Np, Pu, Am, Cm, Bk, Cf, Es, Fm, Md, No, Lr), and any combination thereof.

[0083] In some embodiments, the metal atoms may include one or more rare earth metals or transition metals. In some embodiments, the metal atoms are selected from one or more of Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Nb, Mo, Tc, Ru, Rh, Pd, Ag, Ta, W, Re, Os, Ir, Pt, Au, Hg, Ce, Pr, Nd, Pm, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, Sc, Zn, Y, Zr, Cd, Lu, Hf, La, B, Al, Ga, In, Tl, Si, Ge, Sn, Pb, P, As, or Sb. In some embodiments, the metal atoms are selected from one or more of Ce, Cu, Mn, Fe, Ni, Zn, Ti, and Zr. In some embodiments, the metal atoms are selected from one or more of Ce, Ti, Zr, or Zn. In one embodiment, the metal atom is Ce. The metal atom may be a single metal atom or a cluster of metal atoms, for example, a cluster of two or more different metal atoms as described herein.

[0084] In some embodiments, the metal atom is a metal ion. A metal ion can be monovalent (i.e., a metal ion with only one possible charge). A metal ion can be polyvalent (i.e., a metal ion may have two or more possible charges, e.g., two or more oxidation states). A metal ion may have two or more oxidation states.

[0085] Metals can be polyvalent ions, and metal ions can be unstable / metastable when the polyvalent ion is in a first oxidation state, and stable when the polyvalent ion is in a second oxidation state. For example, a metal ion may have a first oxidation state when bonded to an organic linker, and a second oxidation state when the organic linker is removed.

[0086] A metal ion may be an ion of any one of the metal atoms described herein. In some embodiments, the metal ion is selected from one or more of alkali metals, alkaline earth metals, transition metals, post-transition metals, metalloids, and rare earth metals (including actinides and lanthanides). Non-limiting metal ions are selected from the following groups: alkali metals (e.g., Li, Na, K, Rb, Cs, Fr), alkaline earth metals (e.g., Be, Mg, Ca, Sr, Ba, Ra), transition metals (e.g., Sc, Y, Ti, Zr, Hf, V, Nb, Ta, Cr, Mo, W, Mn, Tc, Re, Fe, Ru, Os, Co, Rh, Ir, Ni, Pd, Pt, Cu, Ag, Au, Zn, Cd, Hg ) Transition metals (e.g., Al, Ga, In, Tl, Sn, Pb, Bi), metalloids (e.g., B, Si, Ge, As, Sb, Te, Po, P), and rare earth metals (e.g., La, Ce, Pr, Nd, Pm, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, Lu, Ac, Th, Pa, U, Np, Pu, Am, Cm, Bk, Cf, Es, Fm, Md, No, Lr), and any combination thereof.

[0087] In some embodiments, the metal ion may comprise one or more rare earth metals or transition metals. In some embodiments, the metal ion is selected from one or more of the following: Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Nb, Mo, Tc, Ru, Rh, Pd, Ag, Ta, W, Re, Os, Ir, Pt, Au, Hg, Ce, Pr, Nd, Pm, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, Sc, Zn, Y, Zr, Cd, Lu, Hf, La, B, Al, Ga, In, Tl, Si, Ge, Sn, Pb, P, As, or Sb. In some embodiments, the metal ion is selected from one or more of the following: Ce, Cu, Mn, Fe, Ni, Zn, Ti, Zr.

[0088] For example, metal ions include Ce 3+ Ce 4+ Ti 4+ , Zr 4+ , or Zn + It may be one or more of the following. In one embodiment, the metal ion is Ce3+ , and / or Ce 4+ The metal atom (including any ion thereof) may be provided as a salt, for example, a hydroxide, nitrate, chloride, acetate, oxalate, formate, peroxide, or sulfate.

[0089] In addition to coordinating to one or more organic linkers according to any embodiment or examples thereof, as described herein, the metal atom may coordinate to one or more further organic ligands. These organic ligands may be oxygen-based ligands. For example, the organic ligand may be hydroxyl or water.

[0090] Organic linkers used in metal-coordinate polymers Layered metal-coordinate polymers contain metal atoms coordinated to organic linkers in order to form metal-coordinate polymer layers. The organic linkers contain metallic bonding moieties. The organic linkers may also contain one or more moieties capable of forming layered metal-coordinate polymers by forming electrostatic interactions with adjacent metal-coordinate polymer layers. The organic linkers stabilize the metal atoms by forming coordinate bonds.

[0091] One or more moieties capable of forming electrostatic interactions with adjacent metal-coordinating polymers may form pendant groups (i.e., terminations) on the opposite side of the organic linker from the metallic-bonding moiety. The metallic-bonding moieties may form coordination bonds (e.g., stronger covalent coordination bonds) with one or more metals, thereby creating stronger interlayer bonds within the metal-coordinating polymer layer. One or more moieties capable of forming electrostatic interactions with adjacent metal-coordinating polymer layers may generate weaker interlayer electrostatic interactions (e.g., weaker van der Waals interactions). Such weaker interlayer electrostatic interactions allow the layered metal-coordinating polymer to be exfoliated into individual metal-coordinating polymer layers, which can act as a platform for preparing thin nanostructures. Furthermore, such weaker interactions allow the metal-coordinating polymer to be decomposed into various morphologies and reconstructed.

[0092] As just one example, the organic linker could be trichloroacetic acid, where the carboxylic acid group is the metallic bonding portion and the trichloromethyl group is the portion capable of forming electrostatic interactions with adjacent metal-coordinate polymer chains. Alternatively, in another example, the organic linker could be formic acid, where the carboxylic acid group is the metallic bonding portion and the terminal hydrogens can form electrostatic interactions with adjacent metal-coordinate polymer layers, for example, the terminal hydrogens of the organic linker on adjacent metal-coordinate polymer chains are scattered between the layers. Rayville Ions can form electrostatic interactions to hold the layers together. For example, terminal hydrogens can form electrostatic interactions with hydroxide ions within the layer or oxygen in water, or any other suitable ions capable of forming hydrogen bonds with terminal hydrogens.

[0093] In one embodiment, the metallic bonding portion is different from one or more portions that can form electrostatic interactions with adjacent metal-coordinate polymer layers.

[0094] In some embodiments, the organic linker may be selected from one or more compounds having the structure of Formula 1: XR 1 (1) During the ceremony: X is the metallic bonding portion that coordinates to the metal atom; and R 1 This is H, or one or more optionally interrupted alkyl, alkenyl, or alkynyl groups substituted with each other to form a layered metal-coordinate polymer by forming electrostatic interactions with adjacent metal-coordinate polymer layers.

[0095] In some embodiments, R 1 H, or one or more optionally interrupted alkyl groups substituted with each other to form a layered metal-coordinate polymer by forming electrostatic interactions with adjacent metal-coordinate polymer layers.

[0096] Metal joining part (X) The metallic bond (X) can be any suitable portion for forming a coordinate bond with one or more metal atoms. In some embodiments, the coordinate bond of the metallic bond to the metal atoms can be a direct bond, e.g., a covalent coordinate bond or a metal-ligand bond, or an indirect bond, e.g., a weaker electrostatic interaction (e.g., a hydrogen bond, a halogen bond), or a van der Waals interaction (e.g., dipole-dipole, dipole-induced dipole, London dispersion force). In one embodiment, the metallic bond forms a covalent coordinate bond with one or more metal atoms. The metallic bond can be a head group on an organic linker, which includes a tail. The tail can be H, or optionally interrupted and substituted alkyl, alkenyl, or alkynyl, as described herein, according to any embodiment or examples thereof.

[0097] The metallic bond portion can be a monodentate, bidentate, or polydentate ligand. In some embodiments, the metallic bond portion is a monodentate or bidentate ligand. The monodentate or bidentate ligand forms a bridging coordination bond with two or more metal atoms to form a metallic coordination polymer layer.

[0098] The metallic linker may have one site that can coordinate with one or more metal atoms. When these organic linkers are used and the metal-coordinate polymer is in the form of multiple sheets, each sheet may be at least partially covered by the organic linker. In some embodiments, the organic linker has two or more sites (e.g., carboxylic acid / carboxylate sites) that can coordinate with one or more metal atoms.

[0099] In some embodiments, the metallic bond includes a metal donor atom. In some embodiments, the metal donor atom is a heteroatom. In some embodiments, the metal donor atom is selected from the group consisting of oxygen, nitrogen, sulfur, selenium, silicon, or tellurium. In some embodiments, the metal donor atom is sulfur, nitrogen, or oxygen. In one embodiment, the metal donor atom is oxygen. In some embodiments, the metal donor atom is a heteroatom in a heteroalkyl, heterocyclyl, or heteroaryl.

[0100] In some embodiments, the metallic bonded moiety includes carboxylic acids (-COOH), hydroxyls (-OH), amines (-NH2), nitros (-NO2), thiols (-SH), nitriles (-CN), substituted or unsubstituted heterocyclines, or substituted or unsubstituted heteroaryls. In some embodiments, the metallic bonded moiety is a carboxylic acid (-COOH). Various metallic bonded moieties, including hydrogen (e.g., carboxylic acid-COOH), include hydrogen (e.g., carboxylate-COO - It should be understood that it can be written without the ) symbol. For example, a carboxylic acid may form a monodentate coordination bond with one or more metal atoms, where hydrogen is retained. Alternatively, a carboxylic acid may form a monodentate or bidentate coordination bond with one or more metal atoms via a carboxylate anion. References to carboxylate herein also refer to carboxylic acids, and the two may be used interchangeably, as will be understood by those skilled in the art.

[0101] In one embodiment, the metallic bond may be a bidentate. Any suitable bidentate metallic bond can be used, for example, the bidentate metallic bond may be a carboxylic acid (-COOH) / carboxylate (-COO - ), may contain amines (-NH2) (e.g., primary amines (-NH2), secondary amines (-NH), tertiary amines (-N(R)-)), thiols (-SH), hydroxyls (-OH), or nitriles (-CN).

[0102] In one embodiment, the metallic bonded portion includes a carboxylic acid group (which may be deprotonated under certain bonding conditions to form a carboxylate group). Each carboxylic acid / carboxylate metallic bonded portion of the organolinker may independently form monodentate or bidentate coordination bonds with one or more metal atoms. In some embodiments, the carboxylic acid / carboxylate metallic bonded portion forms bridging coordination bonds with at least two metal atoms to form a metallic coordination polymer layer.

[0103] In some embodiments, the metallic bonded portion may include a carboxylic acid, carboxylate, acetate, oxalate, acetylacetonate, or catecholate. In one embodiment, the metallic bonded portion is a carboxylic acid and / or carboxylate.

[0104] R 1 basis The organic linker may include one or more parts that form electrostatic interactions with adjacent metal-coordinating polymer layers to form a layered metal-coordinating polymer. One or more parts may be directly attached to the metal-bonding portion. Alternatively, one or more parts may be R as defined above or herein. 1 It can adhere to the metallic bonding portion via the group. If present and not H, R 1 The base can be replaced by one or more parts.

[0105] In some embodiments, the organic linker is R attached to the metal bonding portion. 1 Includes the group R 1 R can be any kind of unsaturated or saturated organic molecule. In some embodiments, R 1 H is H. In some embodiments, R 1 R is an optionally interrupted alkyl, alkenyl, or alkynyl group that is substituted at one or more points to form a layered metal-coordinate polymer by forming electrostatic interactions with adjacent metal-coordinate polymer layers. 1 If is hydrogen, it should be understood that hydrogen can still form electrostatic interactions with adjacent metal coordination polymers to form layered metal coordination polymers. In another embodiment, R 1These are one or more optionally interrupted alkyl groups that are substituted with other elements to form a layered metal-coordinate polymer by forming electrostatic interactions with adjacent metal-coordinate polymer layers.

[0106] The optionally interrupted alkyl, alkenyl, or alkynyl group is optionally interrupted C 1-20 Alkyl, C 2-20 Alkenyl or C 2-20 Alkynyl groups may be selected, each substituting one or more moieties to form a layered metal-coordinate polymer by forming electrostatic interactions with adjacent metal-coordinate polymer layers. Optionally interrupted alkyl, alkenyl, or alkynyl groups are optionally interrupted C 1-10 Alkyl, C 2-10 Alkenyl or C 2-10 Alkynyl groups may be selected, each substituting one or more moieties to form a layered metal-coordinate polymer by forming electrostatic interactions with adjacent metal-coordinate polymer layers. Optionally interrupted alkyl, alkenyl, or alkynyl groups are optionally interrupted C 1-6 Alkyl, C 2-6 Alkenyl or C 2-6 Alkynyl groups may be selected, each of which is substituted with one or more moieties for forming a layered metal-coordinate polymer by forming electrostatic interactions with adjacent metal-coordinate polymer layers. The one or more moieties for forming a layered metal-coordinate polymer by forming electrostatic interactions with adjacent metal-coordinate polymer layers can be provided according to any embodiment or examples thereof as described herein.

[0107] In this embodiment, R 1 H, or optionally interrupted C, which is substituted in one or more parts to form a layered metal coordination polymer by forming electrostatic interactions with adjacent metal coordination polymer layers. 1-20 It is alkyl.

[0108] In this embodiment, R 1 H, or optionally interrupted C, which is substituted in one or more parts to form a layered metal coordination polymer by forming electrostatic interactions with adjacent metal coordination polymer layers.1-10 It is alkyl.

[0109] In this embodiment, R 1 H, or optionally interrupted C, which is substituted in one or more parts to form a layered metal coordination polymer by forming electrostatic interactions with adjacent metal coordination polymer layers. 1-6 It is alkyl.

[0110] In this embodiment, R 1 is H, or optionally interrupted methyl, ethyl, propyl, butyl, pentyl, or hexyl, which is substituted with one or more parts to form a layered metal-coordinate polymer by forming electrostatic interactions with adjacent metal-coordinate polymer layers.

[0111] In this embodiment, R 1 This is H, or one or more substituted methyl atoms to form a layered metal-coordinate polymer by forming electrostatic interactions with adjacent metal-coordinate polymer layers.

[0112] In some embodiments, each R of the organolinker as described above 1 The alkyl group may be optionally interrupted by one or more heteroatoms, for example, one or more O, N, S, Se, Te, Si, and / or one or more alkenyl, alkynyl, aryl, heteroaryl, heteroaryl, and / or cycloalkyl groups, where each of the alkenyl, alkynyl, aryl, heteroaryl, or cycloalkyl groups may be optionally substituted.

[0113] In some embodiments, R 1 One or more of the above-mentioned substituted portions are, for example, due to ions that are reverse-charged in any of the adjacent metal-coordinate polymer chains, and / or one or more scattered between the metal-coordinate polymer layers. Rayville It could be any suitable ion capable of forming electrostatic interactions with adjacent metal-coordinate polymer chains via protons.

[0114] In some embodiments, R 1One or more of the substituted portions above form hydrogen bonds, halogen bonds, and van der Waals interactions (e.g., interdipole, dipole-induced dipole, London dispersion forces) with the adjacent metal-coordinate polymer layer. In one embodiment, R 1 One or more of the substituted parts above form van der Waals interactions with adjacent metal-coordinate polymer layers. Such interactions involve one or more scattered between the metal-coordinate polymer layers. Rayville It can be formed via protons.

[0115] In some embodiments, R 1 It is terminated with one or more portions to form electrostatic interactions with adjacent metal-coordinate polymer layers. For example, R 1 The alkyl terminal hydrogen ions can be substituted in one or more parts to form electrostatic interactions with the adjacent metal-coordinate polymer layer. 1 The terminal hydrogen ion may be substituted with a highly electronegative moiety, for example, a halogen-based moiety, such as a halogen, haloalkyl, haloalkenyl, haloalkynyl, haloalkoxy, haloalkylsulfonyl, or one or more other suitable moieties described herein. Alternatively, R 1 The terminal hydrogen ion can be substituted with a less electronegative moiety, for example, one or more halides selected from the group consisting of Li, Na, K, Rb, or Cs.

[0116] In some embodiments, R 1 One or more of the above-substituted portions were scattered between the metal-coordinate polymer layers. Rayville It forms layered metal-coordinate polymers by creating electrostatic interactions with ions.

[0117] In some embodiments, R is used to form an electrostatic interaction with an adjacent metal-coordinate polymer. 1One or more of the above-substituted portions may be selected from the group consisting of halogens, haloalkyls, haloalkenyls, haloalkoxys, haloalkylsulfonyls, nitriles, hydroxyls, amines, carboxyls, carboxylates, amides, nitros, thiols, sulfonamides, or sulfonyls. In some embodiments, R is used to form electrostatic interactions with adjacent metal-coordinating polymers. 1 One or more of the above-mentioned substituted portions may be selected from the group consisting of halogens, haloalkyls, haloalkenyls, haloalkynyls, haloalkoxys, or haloalkylsulfonyls.

[0118] In some embodiments, R is used to form an electrostatic interaction with an adjacent metal-coordinate polymer. 1 One or more parts replaced above are halogens, C 1-20 Haloalkyl, C 2-20 Haloalkenil, C 2-20 Haloalkynyl, C 1-20 Haloalkoxy, or C 1-20 It may be selected from the group consisting of haloalkylsulfonyls. In some embodiments, R is used to form electrostatic interactions with adjacent metal coordination polymers. 1 One or more parts replaced above are halogens, C 1-10 Haloalkyl, C 2-10 Haloalkenil, C 2-10 Haloalkynyl, C 1-10 Haloalkoxy, or C 1-10 It may be selected from the group consisting of haloalkylsulfonyls. In some embodiments, R is used to form electrostatic interactions with adjacent metal coordination polymers. 1 One or more parts replaced above are halogens, C 1-6 Haloalkyl, C 2-6 Haloalkenil, C 2-6 Haloalkynyl, C 1-6 Haloalkoxy, or C 1-6 It may be selected from the group consisting of haloalkylsulfonyls.

[0119] In some embodiments, R is used to form an electrostatic interaction with an adjacent metal-coordinate polymer.1 One or more of the above-substituted portions may be selected from the group consisting of halogens. In some embodiments, R is used to form electrostatic interactions with adjacent metal coordination polymers. 1 One or more of the parts substituted above may be selected from -F, -Cl, -Br, or -I.

[0120] In some embodiments, R is used to form an electrostatic interaction with an adjacent metal-coordinate polymer. 1 One or more of the above substituted parts are -F, -Cl, -Br, -I, -CF3, -CI3, -CCl3, -CBr3, -CHF2, -CHCl2, -CHI2, -CHBr2, -OCH2F, -OCH2Cl, -OCH2I, -OCH2Br, -OCHF2, -OCHCl2, -OCHI2, -OCHBr2, -OCF3, -OCl3, -OCI3, -OCBr3, -CN, -OH, -NH2, -COOH, -CONH2, -NO2, -SH, -SO3H, -SO4H, -SO2NH2, -NHNH2, -ONH2, -NHC= (O)NHNH2, -NHC=(O)NH2, -NHSO2H, -NHC=(O)H, -NHC(O)-OH, -NHOH, substituted or unsubstituted alkyl (e.g., C1-C8, C1-C6, or C1-C4), substituted or unsubstituted heteroalkyl (e.g., 2-8 membered, 2-6 membered, or 2-4 membered), substituted or unsubstituted cycloalkyl (e.g., C3-C8, C3-C6, or C5-C6), substituted or unsubstituted heterocyclyl (e.g., 3-8 membered, 3-6 membered, or 5-6 membered), substituted or unsubstituted aryl (e.g., C6-C 10 , C 10 The group may be selected from those consisting of phenyl, or substituted or unsubstituted heteroaryls (e.g., 5-10 membered, 5-9 membered, or 5-6 membered).

[0121] In some embodiments, R is used to form an electrostatic interaction with an adjacent metal-coordinate polymer. 1One or more of the portions replaced above may be selected from the group consisting of -F, -Cl, -Br, -I, -CF3, -CI3, -CCl3, -CBr3, -CHF2, -CHCl2, -CHI2, -CHBr2, -OCH2F, -OCH2Cl, -OCH2I, -OCH2Br, -OCHF2, -OCHCl2, -OCHI2, -OCHBr2, -OCF3, -OCl3, -OCI3, and -OCBr3.

[0122] In some embodiments, R 1 is selected from the group consisting of H, alkyl, alkenyl, alkynyl, alkoxy, haloalkyl, haloalkenyl, haloalkynyl, haloalkoxy, haloalkylsulfonyl, alkylamine, alkylcarboxylic acid, alkylamide, alkylthiol, alkylsulfonamide, or alkylsulfonyl.

[0123] In some embodiments, R 1 is selected from the group consisting of H, alkyl, haloalkyl, haloalkoxy, alkylamine, alkylcarboxylic acid, alkylthiol, alkylsulfonamide, or alkylsulfonyl. In some embodiments, R 1 is selected from the group consisting of H, alkyl, halogen, haloalkyl, and alkylcarboxylic acid.

[0124] In some embodiments, R 1 is selected from the group consisting of H, C 1-20 alkyl, C 1-20 haloalkyl, and C 1-20 carboxylic acid. In some embodiments, R 1 is selected from the group consisting of H, halogen, C 1-10 alkyl, C 1-10 haloalkyl, and C 1-10 carboxylic acid.

[0125] In some embodiments, R 1-CF3, -CI3, -CCl3, -CBr3, -CHF2, -CHCl2, -CHI2, -CHBr2, -OCH2F, -OCH2Cl, -OCH2I, -OCH2Br, -OCHF2, -OCHCl2, -OCHI2, -OCHBr2, - OCF3, -OCl3, -OCI3, -OCBr3, -CN, -OH, -NH2, -COOH, -CONH2, -NO2, -SH, -SO3H, -SO4H, -SO2NH2, -NHNH2, -ONH2, -NHC=(O)NHNH2, -NHC=( O)NH2, -NHSO2H, -NHC=(O)H, -NHC(O)-OH, -NHOH, substituted or unsubstituted alkyl (e.g., C1-C8, C1-C6, or C1-C4), substituted or unsubstituted heteroalkyl (e.g., 2-8 member, 2-6 member, or 2-4 member), substituted or unsubstituted cycloalkyl (e.g., C3-C8, C3-C6, or C5-C6), substituted or unsubstituted heterocycloalkyl (e.g., 3-8 member, 3-6 member, or 5-6 member), substituted or unsubstituted aryl (e.g., C6-C 10 , C 10 Selected from the group consisting of phenyl, or substituted or unsubstituted heteroaryls (e.g., 5-10 member, 5-9 member, or 5-6 member).

[0126] In some embodiments, the metal atom is Ce 3+ Ce 4+ Ti 4+ , Zr + or Zn + The ion is selected from, where X is -COOH, -SH, -NH2, -OH, and R 1 -CF3, -CI3, -CCl3, -CBr3, -CHF2, -CHCl2, -CHI2, -CHBr2, -OCH2F, -OCH2Cl, -OCH2I, -OCH2Br, -OCHF2, -OCHCl2, -OCHI2, -OCHBr2, -OCF3, -OCl3, -OCI3, or -OCBr3 is selected from -CF3, -CI3, -CCl3, -CBr3, -CBr3.

[0127] In some embodiments, the organic linker is organic-based. In some embodiments, the organic linker comprises alkyl-, alkene-, alkyne-, and / or aryl-based carboxylic acids. For example, the organic linker may be a halide-substituted alkyl acid such as trichloroacetic acid. In some embodiments, the organic linker comprises formic acid. In some embodiments, the organic linker may act as a Lewis acid and the metal atom as a Lewis base, or vice versa.

[0128] In some embodiments, the organic linker is a carboxylic acid. In some embodiments, the organic linker is formic acid, trifluoroacetic acid, trichloroacetic acid, tribromoacetic acid, or triiodoacetic acid. In one embodiment, the organic linker is formic acid or trichloroacetic acid. In one embodiment, the organic linker is trichloroacetic acid.

[0129] To obtain a layered metal-coordinate polymer (where each layer contains stronger intralayer coordination covalent bonds between the organic linker and one or more metal atoms throughout the layer, and weaker interlayer electrostatic interactions), in some embodiments, the organic linker does not form coordination bonds to the metal atoms of adjacent metal-coordinate polymer layers. This allows each layer of the layered metal-coordinate polymer to be held together by weak van der Waals interactions between the layers.

[0130] Layered metal-coordinate polymers Layered metal-coordinate polymers can be unstable. Unstable layered metal-coordinate polymers are inherently unstable, but can exist indefinitely due to the presence of an organolinker, such as a metal center or substructure (e.g., [Ce(OH)2]). 2+) include, thereby efficiently “capping” and stabilizing unstable metal centers or substructures of the coordination polymer. Unstable metal centers or substructures may also be called “reactive metal-based species.” When removing a stabilizing or “capping” organic linker, the metal tends to form more stable metal-based species, such as nanostructures. For example, a reactive metal-based species may be a metal atom (e.g., a metal ion) with an unsaturated coordination number that tends to form covalent bonds to fill coordination sites when an organic linker is removed. The conversion from an unstable / metastable state to a stable state may be achieved via an intermediate. For example, in some embodiments, a reactive metal-based species may tend to form an unstable / metastable intermediate that is rapidly converted to a more stable metal-based species when an organic linker is removed. However, unstable / metastable intermediates are not formed in all embodiments. The terms “unstable” and “metastable” may be used interchangeably throughout this disclosure.

[0131] Prior to this disclosure, unstable metal-coordinate polymers were previously avoided as potential precursors for forming nanostructures because these properties meant they could not be used as nanostructure materials at any given time. However, the advantage of this instability is that unstable metal-coordinate polymers can be used as precursor materials to create other nanostructures having specific structures.

[0132] Unstable metal-coordination polymers can also retain their structure or architecture during the formation of nanostructures. This retention of structure was not previously anticipated in the use of unstable metal-coordination polymers. Furthermore, polycrystalline nanostructures can be formed using unstable metal-coordination polymers as precursors, which was also not previously considered in the use of unstable metal-coordination polymers.

[0133] Reactive metal-based species containing metals coordinated to an organic linker form part of a metal-coordinate polymer. By being stabilized by the organic linker, the reactive metal-based species can exist in a "reactive" (or metastable) state. Removal of the organic linker allows the unstable metal-based species to be converted to a more stable state (i.e., a more stable metal-based species). In some embodiments, the organic linker stabilizes the metal atom by forming a coordination bond with the organic linker. In other words, the ligand helps to "cap" the reactive metal-based species, preventing it from forming a more stable metal-based species. Removal of such a capping linker results in the conversion of the unstable metal-based species into a more stable metal nanostructure.

[0134] In some embodiments, the layered metal coordination polymer consists of multiple metal coordination polymer layers scattered between them. Rayville Contains ions. Rayville The term "ion" refers to ions that can be scattered through the interlayer spaces between layers of metal-coordinate polymers. Rayville Ions can form electrostatic interactions between one or more portions of the organic linkers in each metal-coordinate polymer layer, thereby forming a layered metal-coordinate polymer. Rayville Ions can have either a positive or negative charge. Rayville Ions are acidic protons (H + ) This is possible. Protons can be introduced in situ during the synthesis of metal-coordinated polymers. Rayville Ions can form electrostatic interactions with one or more moieties that are terminal organic linkers to form layered metal-coordinate polymers. For example, if the organic linker is acidic (e.g., trichloroacetic acid), Rayville The ions can be acidic protons and can intercalate between sheets. Intercalated protons can help hold layered materials together. For example, protons can act as weak electrostatic crosslinking agents.

[0135] RayvilleThe ions may have the opposite charge to one or more terminal parts of the organic linker. For example, if the organic linker is terminated with one or more negatively charged ions, such as those containing halogen parts (e.g., F, Cl, Br, I), Rayville Ions are positive, for example, protons (H + ) may be the case. Alternatively, if the organic linker is terminated with hydrogen or one or more positive ions (e.g., Li, Na, K, Rb, and / or Cs), Rayville Ions can carry a negative charge (for example, OH - ). Rayville The ions may originate from the carboxylic acid metal bond portion of the organolinker, and / or from the metal source used in the preparation of the metal-coordinate polymer, and / or from the solvent system (e.g., H2O) used in the preparation of the metal-coordinate polymer.

[0136] In some embodiments, Rayville The electrostatic interaction between ions and one or more terminal portions of the organic linker can be substantially orthogonal (e.g., perpendicular) to the coordination bonds within the metal coordination polymer. Such orientation of interlayer and intralayer bonds results in the ability to exfoliate the layered metal coordination polymer into one or more individual metal coordination polymer layers under relatively simple conditions.

[0137] between layers RayvilleDue to the presence of ions (e.g., protons), metal-coordinate polymers have a surface charge. In some embodiments, the surface charge is positive. The surface charge can be positive or negative. The surface charge can be positive. Layered metal-coordinate polymers may have a zeta potential (indicating the surface charge). Layered metal-coordinate polymers may have a zeta potential greater than zero (0) mV. In some embodiments, layered metal-coordinate polymers have a zeta potential of at least 1, 2, 5, 10, 15, 20, 30, 40, 50, 60, 80, or 100 mV. In some embodiments, layered metal-coordinate polymers have a zeta potential less than 100, 80, 60, 50, 40, 30, 20, 15, 10, 5, 2, or 1 mV. Any combination of two or more of these upper and / or lower zeta potential values, for example, about 5 mV to about 100 mV, 5 mV to about 80 mV, or about 10 mV to about 60 mV, for example, about +30 mV, is also possible. Figure 69 shows the zeta potentials of layered metal-coordinate polymers according to at least some embodiments or examples described herein.

[0138] In some embodiments, the metal coordination polymer may be a metal coordination polymer layer that is not electrostatically linked to another layer (i.e., not crosslinked to form a bulk layered polymer). For example, the layered metal coordination polymer can be exfoliated to obtain one or more individual metal coordination polymer layers.

[0139] In some embodiments, the metal coordination polymer is a non-crosslinked metal coordination polymer containing metal atoms coordinated to an organic linker to form a metal coordination polymer layer, the organic linker being described herein. The metal coordination polymer layer may be planar or linear. In some embodiments, two or more metal coordination polymer layers may interact electrostatically (i.e., crosslink) to form a layered metal coordination polymer, the metal coordination polymer layers being held together by electrostatic interactions between organic linkers on each metal coordination polymer layer, as described herein.

[0140] It should be understood that metal-coordinate polymers can incorporate other organic ligands that coordinate to one or more metal atoms, in addition to organic linkers, such as negatively charged ions, negatively charged complexes, and / or dipole molecules (e.g., water and / or hydroxide ions), which may originate, for example, from the metal salts and / or solvents used in the preparation of the metal-coordinate polymer.

[0141] In some embodiments, each metal atom of the metal-coordinating polymer can independently coordinate to at least 5, 6, 7, or 8 atoms from the metal-bonding moiety and / or one or more further organic ligands.

[0142] In one embodiment, the metal coordination polymer is a cerium metal coordination polymer having the formula Ce(TCA)2(OH)2·2H2O. The cerium metal coordination polymer can be characterized by an X-ray powder diffraction (XRD) pattern containing one or more major peaks located at approximately 7.2, 8.1, 10.9, 20.6, 22.0, 23.1, and / or 23.2°(2θ). One or more of these peaks can be used to characterize the cerium metal coordination polymer. The cerium metal coordination polymer can be characterized by the XRD pattern provided in Figure 8.

[0143] A layered metal coordination polymer includes layers having a specific thickness along the layer (referred to as the axial thickness along the c-axis of the metal coordination polymer layer). In some embodiments, each metal coordination polymer layer may independently have an axial thickness along the c-axis of 100, 70, 50, 20, 15, 10, 8, 6, 4, 2, or less than 1 nm, for example, 20, 15, 12, 10, 8, 5, 2, or less than 1 nm. Any combination of any two of these upper and / or lower thickness limits can provide a range selection, e.g., about 1 nm to about 12 nm. In one embodiment, each metal coordination polymer layer may independently have an axial thickness of about 1.1, 2.2, 5.5, or 11 nm, where the thickness is proportional to the thickness of one unit cell of the metal coordination polymer. In some embodiments, each metal coordination polymer layer may have a unit cell thickness of about 1, 2, 3, 4, 5, 6, 7, 8, 9, or 10. The thickness can be measured using scanning electron microscopy or atomic force microscopy (AFM).

[0144] Method for preparing metal-coordinate polymers One of the main objectives of the metal coordination polymer preparation methods described herein is to establish synthetic conditions that can produce layered metal coordination polymers held together by weak electrostatic interactions. Depending on the reaction conditions, unstable metal coordination polymers can be prepared, which can then be used to prepare various nanostructures.

[0145] The metal coordination polymers described herein may be prepared by combining (i.e., bringing into contact with) a metal atom source and an organic linker to form a layered metal coordination polymer comprising two or more metal coordination polymer layers held together by electrostatic interaction. The terms “combining” or “bringing into contact” may include reacting, interacting, or physically bringing together two species, the two species may be an organic linker and a metal atom as described herein, and may optionally be one or more other species, including a gas, such as oxygen.

[0146] The metal atom source may include any metal atom (e.g., metal ion) as described herein for metal coordination polymers, for example, those described under the heading "Metals Used in Metal Coordination Polymers." The metal atom source may typically include one or more metals selected from alkali metals, alkaline earth metals, transition metals, post-transition metals, metalloids, or rare earth metals (including actinides and lanthanides). Non-limiting metal atoms are derived from the following groups: alkali metals (e.g., Li, Na, K, Rb, Cs, Fr), alkaline earth metals (e.g., Be, Mg, Ca, Sr, Ba, Ra), transition metals (e.g., Sc, Y, Ti, Zr, Hf, V, Nb, Ta, Cr, Mo, W, Mn, Tc, Re, Fe, Ru, Os, Co, Rh, Ir, Ni, Pd, Pt, Cu, Ag, Au, Zn, Cd, Hg), and transition metals. Transfer metals (e.g., Al, Ga, In, Tl, Sn, Pb, Bi), metalloids (e.g., B, Si, Ge, As, Sb, Te, Po, P), and rare earth metals (e.g., La, Ce, Pr, Nd, Pm, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, Lu, Ac, Th, Pa, U, Np, Pu, Am, Cm, Bk, Cf, Es, Fm, Md, No, Lr), and any combination thereof. A metal source may contain ions of one or more of the metals described herein. Metal ions may be monovalent or monovalent (i.e., metal ions with only one possible charge). Metal ions may be polyvalent (i.e., metal ions may have two or more possible charges, e.g., two or more oxidation states). Metal ions may have two or more oxidation states. A metal source may contain polyvalent ions.

[0147] In some embodiments, the metal ion source may include one or more rare earth metals or transition metals. In some embodiments, the metal ion is selected from one or more of the following: Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Nb, Mo, Tc, Ru, Rh, Pd, Ag, Ta, W, Re, Os, Ir, Pt, Au, Hg, Ce, Pr, Nd, Pm, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, Sc, Zn, Y, Zr, Cd, Lu, Hf, La, B, Al, Ga, In, Tl, Si, Ge, Sn, Pb, P, As, or Sb. In some embodiments, the metal ion is selected from one or more of the following: Ce, Cu, Mn, Fe, Ni, Zn, Ti, Zr. For example, the metal ion source is Ce 3+ Ce 4+ Ti 4+ , Zr 4+ , or Zn + It may contain one or more of the following. In one embodiment, the metal ion is Ce 3+ and / or Ce 4+ The metal atomic source (including any ions thereof) may be provided as one or more salts of any of the metals described herein, for example, hydroxides, nitrates, chlorides, acetates, oxalates, formates, peroxides, or sulfates.

[0148] The organic linker may be any organic linker as described herein for metal coordination polymers. The organic linker includes a metal-binding moiety. The organic linker may also include one or more moieties capable of forming electrostatic interactions with adjacent metal coordination polymer layers to form a layered metal coordination polymer. In some embodiments, the organic linker may be selected from one or more compounds having the structure of Formula 1: XR 1 (1) During the ceremony: X is the metallic bonding portion that coordinates to the metal atom; and R 1is H, or one or more optionally interrupted alkyl, alkenyl, or alkynyl groups substituted with each other to form the layered metal coordination polymer by forming electrostatic interactions with the adjacent metal coordination polymer layer. In some embodiments, R 1 H, or one or more optionally interrupted alkyl groups substituted with each other to form a layered metal-coordinate polymer by forming electrostatic interactions with adjacent metal-coordinate polymer layers. Metal bond moieties and R 1 This refers to the bonding portion and R described herein for metal coordination polymers. 1 For example, they can be selected from those described under the title "Organolinkers Used in Metal-Coordination Polymers." In some embodiments, the organic linker is a carboxylic acid. In some embodiments, the organic linker is formic acid, trifluoroacetic acid, trichloroacetic acid, tribromoacetic acid, or triiodoacetic acid. In one embodiment, the organic linker is formic acid or trichloroacetic acid. In one embodiment, the organic linker is trichloroacetic acid.

[0149] Combining a metal atom source with an organic linker may involve mixing the metal atom source and the organic linker. The metal atom source and the organic linker may be mixed using solvent-free conditions, such as sol-gel techniques. Alternatively, they may be mixed using an aqueous solution or a solvent. The mixture may then be heated. Suitable techniques for forming layered metal-coordinate polymers include hydrothermal, solvothermal, and electrodeposition processes. A mixture of the metal atom source and the organic linker may be formed using a polar solvent (e.g., water or an organic solvent). For example, if the organic linker is an organic acid, the metal salt (e.g., the metal atom source) and the organic acid may be mixed.

[0150] In some embodiments, the process may include mixing an aqueous solution containing a metal atom source and an organic linker to form a layered metal-coordination polymer comprising two or more metal-coordination polymer layers held together by electrostatic interaction. In some embodiments, the step of forming the layered metal-coordination polymer includes heating the aqueous solution containing the metal atom source and the organic linker.

[0151] The reaction conditions may depend on the type of metal-coordinate polymer to be formed. In some embodiments, a mixture of the metal atom source and the organic linker may be subjected to hydrothermal or solvothermal treatment.

[0152] In one embodiment, the step of forming a layered metal coordination polymer includes, for example, electrodeposition to prepare a cerium-based metal coordination polymer.

[0153] Electrodeposition may be modified anodic chronoamperometry (MACE). The electrodeposition process may include three electrodes: a fluorine-doped tin oxide on a glass working electrode, a platinum wire counter electrode, and an Ag / AgCl reference electrode. Other electrodes may also be used. Examples of suitable electrodeposition configurations are provided in Figures 49 and 50, but these should not be considered limiting.

[0154] MACE can be performed within the oxygen-evolving region of an aqueous solution containing a metal atom source and an organic linker. The oxygen-evolving region varies depending on the metal atom and organic linker system, but can be easily determined by those skilled in the art using a Poole-Bay diagram available to them. An example of a Poole-Bay diagram for cerium and trichloroacetic acid is provided in Figure 7, but this should not be considered limiting. By performing electrodeposition in the oxygen-evolving region of an aqueous solution containing a metal atom and an organic linker, oxygen molecules are generated at the working electrode, resulting in the oxidation of metal species (e.g., Ce(III) to Ce(IV)) that can form unstable metal-coordination polymers.

[0155] The concentrations of the metal atom source and the organic linker in the aqueous solution are, respectively, limited by the maximum solubility of the precursor water-soluble salt used as the metal atom source. In some embodiments, the concentrations of the metal atom source and the organic linker in the aqueous solution are independently at least about 0.001, 0.01, 0.02, 0.05, 0.08, 0.1, 0.2, 0.4, 0.5, 0.8, or 1 M. In some embodiments, the concentrations of the metal atom source and the organic linker in the aqueous solution are independently less than about 1, 0.8, 0.5, 0.4, 0.2, 0.1, 0.08, 0.05, 0.02, 0.01, or 0.001 M. Any combination of two or more of these upper and / or lower concentration limits, for example, about 0.001 M to about 1 M or about 0.01 M to about 0.1 M, is also possible.

[0156] The initial pH of the aqueous solution or mixture can be adjusted. In some embodiments, the initial pH of the aqueous solution during electrodeposition may be an acidic pH, for example, less than about pH 7. The pH can be adjusted by adding an appropriate amount of acid or base depending on the acidity of the aqueous solution containing the metal atom source and the organic linker. In some embodiments, the initial pH of the aqueous solution during electrodeposition may be less than about 7, 6, 5, 4, 3, or 2. Combinations of these pH values ​​are also possible, for example, the initial pH of the aqueous solution during electrodeposition may be about pH 2 to about pH 7, about pH 3 to about pH 7, about pH 5 to about pH 6, for example, about pH 4, 4.2, 4.4, 4.6, 4.8, 5, 5.2, 5.4, 5.6, 5.8, 6.0, 6.2, 6.4, 6.8, or 7.0.

[0157] Electrodeposition is performed using a constant applied voltage effective in maintaining the oxygen-evolving region of the aqueous solution containing the metal atomic source and the organic linker. The voltage used for electrodeposition may be determined by the surface area of ​​the working electrode. The voltage may be proportional to the dimensions of the working electrode. The voltage used for electrodeposition may be determined by the aqueous or solvent system used for electrodeposition. In one embodiment, the voltage (i.e., potential) used for electrodeposition may be within the oxygen-evolving region of the aqueous solution containing the metal ions and the organic linker, as determined, for example, by a Poole-Bay diagram.

[0158] In some embodiments, electrodeposition is carried out using a constant applied voltage pair of Ag / AgCl of at least about 0.001, 0.01, 0.05, 0.1, 0.2, 0.5, 0.8, 1, 2, 3, 4, 5, 6, 7, 8, 9, or 10 V. In some embodiments, electrodeposition is carried out using a constant applied voltage pair of Ag / AgCl of less than 10, 9, 8, 7, 6, 5, 4, 3, 2, 1, 0.8, 0.5, 0.2, 0.1, 0.05, 0.01, or 0.001 V. Any combination of two or more of these upper and / or lower voltage limits, e.g., about 1.0 V to 10.0 V, about 1.0 V to 5.0 V, or about 1.0 V to 2.0 V, is also possible. Other applied voltages are also possible depending on the metal atoms and organic linkers and can be selected based on a suitable pool-bay diagram of a given metal and organic linker system, as will be understood by those skilled in the art. By applying a voltage effective in maintaining the oxygen-evolving region of the aqueous solution, oxygen is generated at the working electrode, oxidizing metal atoms, for example, from Ce(III) to Ce(IV). Simultaneously, protons can also be rapidly generated, lowering the local pH. The local pH of the aqueous solution during electrodeposition can be lowered to a more acidic pH compared to the initial pH of the aqueous solution, for example, the local pH can be lowered to approximately pH 1 to approximately pH 3, for example, approximately pH 3, 2.8, 2.6, 2.4, 2.2, or less than 2.0. The local pH of the aqueous solution during electrodeposition can be lower than the initial pH of the aqueous solution.

[0159] Proton generation during electrodeposition involves one or more Rayville This can provide a source of ions (e.g., protons), which are scattered between the metal-coordinate polymer layers, and each R of the organic linker in each metal-coordinate polymer layer. 1 Electrostatic interactions are formed between one or more portions of the arbitrarily interrupted alkyl groups to form a layered metal coordination polymer.

[0160] Electrodeposition may be carried out at a suitable temperature, for example, at least about 0, 5, 10, 15, 20, 25, 30, 40, 50, 70, 90, or 100°C. Electrodeposition may also be carried out at temperatures below about 100, 90, 70, 50, 40, 30, 25, 20, 15, 10, or 5°C. Combinations of two or more of these upper and / or lower temperature ranges, for example, about 0°C to about 100°C, about 10°C to 60°C, or 25°C to 50°C, are also possible. In some embodiments, electrodeposition may be carried out at room temperature (e.g., 25°C), however, higher temperatures can accelerate the diffusion rate and reaction rate of the formation of the metal-coordinate polymer.

[0161] Electrodeposition may be carried out over a set period of time suitable for forming the metal-coordinate polymer, for example, at least about 1, 2, 5, 10, 15, 20, 30, 60, or 90 minutes. Electrodeposition may also be carried out over a set period of less than 90, 60, 30, 20, 15, 10, 5, 2, or 1 minute. Combinations of two or more of these upper and / or lower reaction time limits, for example, about 1 minute to 90 minutes, about 10 minutes to 90 minutes, or about 30 minutes to about 90 minutes, are possible.

[0162] In some embodiments, the metal may have a low field intensity in a low oxidation state within a viable working pH range of an aqueous solution containing metal atoms and an organic linker to form a metal coordination polymer, as described herein. The working pH range may be determined by a Poole-Bay diagram. The oxidation state of the metal may increase when oxidized in an acidic pH environment, as described herein. In some embodiments, an unsaturated metal hydroxide (M(OH) x n+ ) can form an acidic pH under high oxidation conditions.

[0163] The architecture of layered materials can be altered by decomposing and reconstructing layered metal-coordinate polymers using different solvent systems. For example, in polar solvents such as water, layered metal-coordinate polymers may be preferentially exfoliated rather than altering their architecture. When using low-polarity solvents such as ethanol or other organic solvents, layered metal-coordinate polymers can be differentiated and then reconstructed. The method for reconstructing layered metal-coordinate polymers may depend on the concentration of the layered metal-coordinate polymer, the type of solvent, the use of solvent systems such as gradient solvent systems, the evaporation rate, heating, cooling, pH, and the introduction of groups that induce layering, such as salts. By altering the architecture of layered metal-coordinate polymers, different nanostructures can be formed from a single precursor layered material.

[0164] In some embodiments, the layered metal-coordinate polymer is decomposed in an organic solvent and reconstructed from the organic solvent by evaporation. In some embodiments, the organic solvent is an alcohol, such as methanol, ethanol, propanol, butanol, pentanol, and preferably ethanol. In some embodiments, the organic solvent is a polar aprotic solvent, such as dichloromethane, NMP, THF, acetate, acetone, DMF, acetonitrile, or DMSO, or an amine, such as triethylamine. In some embodiments, the organic solvent is an amine, such as triethylamine. In some embodiments, the organic solvent is acetone.

[0165] The concentration of the metal-coordinate polymer that decomposes in an organic solvent is limited by the maximum solubility of the metal-coordinate polymer in the organic solvent. In some embodiments, the concentration of the metal-coordinate polymer that decomposes in an organic solvent is at least about 1, 2, 4, 5, 10, 20, 50, 70, 90, 100, 110, or 120 M. In some embodiments, the concentration of the metal-coordinate polymer that decomposes in an organic solvent is less than about 120, 110, 100, 90, 70, 50, 20, 10, 5, 4, 2, or 1 M. Any combination of any two of these upper and / or lower concentration limits can provide range selection, e.g., about 1 M to about 200 M, or about 4 M to about 120 M.

[0166] The evaporation of organic solvents is carried out at temperatures and vapor pressures limited by the maximum solubility of the organic solvent in air. In some embodiments, the evaporation of organic solvents is carried out at temperatures of at least about -20, -15, -10, -5, 0, 5, 10, 15, 20, 30, 40, or 50°C. In some embodiments, the evaporation of organic solvents is carried out at temperatures below about 50, 40, 30, 20, 15, 10, 5, 0, -5, -10, -15, or -20°C, or at temperatures greater than about -20, -15, -10, -5, 0, 5, 10, 15, 20, 30, 40, or 50°C. Any combination of two or more of these upper and / or lower evaporation temperature limits, for example, about -20°C to about 40°C, or about -10°C to about 25°C, is possible. In some embodiments, evaporation of the organic solvent is carried out at a vapor pressure of at least about 0.1, 0.2, 0.5, 0.7, 1, 2, 5, 7, 10, 15, or 20 kPa. In some embodiments, evaporation of the organic solvent is carried out at a vapor pressure of less than about 20, 15, 10, 7, 5, 2, 1, 0.7, 0.5, 0.2, or 0.1 kPa. Any combination of two or more of these upper and / or lower vapor pressure limits is possible, for example, about 0.1 kPa to about 20 kPa, about 0.1 kPa to about 10 kPa, 0.5 kPa to about 10 kPa, or about 0.7 kPa to about 10 kPa. It should be understood that any single or range of vapor pressure and evaporation temperature can be combined. In some embodiments, the evaporation time can be at least about 1 minute, 15 minutes, 30 minutes, 1, 2, 3, 4, 6, 8, 12, 18, 24, 48, or 72 hours. These combinations of evaporation times are possible, for example, from approximately 6 hours to 72 hours.

[0167] The layered metal coordination polymer may be exfoliated to obtain one or more metal coordination polymer layers. In some embodiments, the step of exfoliating the layered material is performed to remove the metal coordination polymers scattered within each layer. Rayville Includes removing ions. Scattered Rayville Ion removal can disrupt the electrostatic interactions between metal-coordinate polymer layers (e.g., dispersion of metal-coordinate polymer layers) for obtaining one or more metal-coordinate polymer layers. For example, increasing the pH of the dispersion or solution of layered metal-coordinate polymers can disrupt the scattered ions. RayvilleIons (e.g., protons) may be removed. Generally, scattered Rayville Ion removal occurs at the edges of the layered metal-coordinate polymer, weakening the van der Waals forces that hold the layers together and allowing water or solvent molecules to penetrate between adjacent sheets. The propagation front of ion removal and water or solvent penetration then proceeds from the edges towards the interior of the layered metal-coordinate polymer. Thus, in some embodiments, water or solvent penetration causes delamination. In some embodiments, the layered metal-coordinate polymer is delaminated by stirring in water. However, delamination is not limited to water or solvent penetration and can be facilitated, for example, by adjusting the temperature, chemical environment, etc.

[0168] In some embodiments, the delamination of the layered metal coordination polymer occurs when particles are scattered between each metal coordination polymer layer. Rayville By removing ions, each R of the organic linker in each metal-coordinate polymer layer 1 This involves disrupting the electrostatic interactions between one or more portions of optionally interrupted alkyl groups to obtain one or more metal-coordinate polymer layers.

[0169] Stripping may be carried out by dispersing the metal-coordinate polymer in a suitable solvent (e.g., water or an organic solvent), and further by heating and / or stirring, e.g., stirring or (ultra) sonication. Stripping may be assisted by chemical means. Stripping may be assisted by heating and / or sonication. Stripping may be carried out using any solvent, e.g., water, alcohol, e.g., methanol, ethanol, propanol, butanol, pentanol, etc.; preferably, ethanol, polar aprotic solvent, e.g., dichloromethane, NMP, THF, acetate, acetone, DMF, acetonitrile, or DMSO, or amine, e.g., triethylamine.

[0170] In some embodiments, the exfoliation of a layered metal coordination polymer involves dispersing the layered metal coordination polymer in water or an organic solvent, stirring, and exfoliating the layered metal coordination polymer to obtain one or more metal coordination polymer layers. The layered metal coordination polymer may be stirred at a temperature of about 5°C to about 50°C, for example, about room temperature. The layered metal coordination polymer may be stirred for a certain period of time that is effective in exfoliating the layered metal coordination polymer (for example, by sonication) to obtain one or more metal coordination polymer layers. Suitable stirring times for exfoliating a layered metal coordination polymer to obtain one or more metal coordination polymer layers include, for example, about 1 minute to about 72 hours, about 1 minute to about 60 minutes, or about 1 minute to about 20 minutes.

[0171] In some embodiments, the decomposition of the layered metal coordination polymer in an organic solvent also exfoliates the layered metal coordination polymer. In some embodiments, combined exfoliation and decomposition can be accelerated by similar polarity indices of the metal coordination polymer and the solvent, e.g., organic or inorganic. In embodiments, exfoliation can be accelerated by different polarity indices (within the range of 1 to 10) of the metal coordination polymer and the solvent. Similar polarity indices are, for example, in the range of ±2; different polarity indices are, for example, in the range of ±3 to 9.

[0172] In some embodiments, the step of forming a layered metal coordination polymer includes hydrothermal treatment of an aqueous solution containing metal atoms and an organic linker, as described herein. The initial pH of the aqueous solution during hydrothermal treatment may be less than about 7. The hydrothermal treatment may be carried out at a temperature range of about 25°C to about 200°C, or about 25°C to about 100°C, for example, less than about 100°C. Suitable techniques for hydrothermal treatment are known to those skilled in the art.

[0173] Process for preparing nanostructures The metal-coordination polymers disclosed herein are relatively unstable precursors and provide a platform for controllable decomposition to form a number of useful and / or previously unattainable nanoarchitectures, ranging from nanosheets that can be made extremely thin to diverse two- and three-dimensional nanostructures that can have features that vary the degree of defects. Unexpectedly and advantageously, these diverse nanostructures can be obtained in a controlled manner from a single metal-coordination polymer precursor. For example, exfoliation of a metal-coordination polymer can ultimately produce nanosheets containing metal oxides (MOs), which can be made as thin as a single unit cell and can be appropriately diversified with useful transition metals, for example. On the other hand, decomposition / reconstruction of metal-coordination polymers under certain conditions can provide diverse two- and three-dimensional nanostructures based on the morphology of the reconstructed metal-coordination polymer. The assembly / reconstruction process can be controlled by varying parameters such as solvent type, solute concentration, temperature, and time. Both initial steps of exfoliation and / or decomposition / reconstruction involve removing the metal-coordinate polymer coordinating organic linker, followed by the transformation of the initial metal-coordinate polymer structure into a corresponding nanostructure, such as a porous metal oxide nanosheet.

[0174] Accordingly, in one aspect of this disclosure, the present disclosure provides a method for forming a nanostructure, comprising providing a layered metal coordination polymer comprising two or more layers, each layer comprising a metal atom each coordinated to one or more organic linkers in order to form a metal coordination polymer, and removing at least a portion of the coordinating organic linkers to form a nanostructure.

[0175] In some embodiments, the method includes providing a layered metal-coordination polymer having many metal atoms stabilized by coordinating to one or more organic linkers. In some embodiments, the layered metal-coordination polymer includes many reactive metal-based centers (i.e., reactive metal-based species) stabilized by coordinating to one or more organic linkers. In some embodiments, the method may include removing at least a portion of the coordinating organic linkers to expose unstable metal-based species (which then form nanostructures by being converted to more stable metal-based species). In some embodiments, the unstable metal-based species are converted to one or more more stable intermediates, and then converted to more stable metal-based species to form the resulting nanostructure.

[0176] According to this method, at least a portion of the coordinating organic linker is removed to form a nanostructure. In some embodiments, the step of removing at least a portion of the coordinating organic linker to form a nanostructure includes aging a layered metal-coordinating polymer.

[0177] As used herein, the term “aging” refers to the physical and / or chemical changes of a material over time, for example, aging a metal-coordinate polymer to form nanostructures.

[0178] In some embodiments, aging a layered metal-coordinate polymer involves heating the metal-coordinate polymer. For example, a layered metal-coordinate polymer may be heated to a temperature sufficient to decompose the organic linker and form nanostructures. A sufficient temperature may be, for example, 100°C to 1000°C, preferably 100°C to 850°C, and more preferably 100°C to 700°C. In some embodiments, the temperature may be at least about 50, 75, 100, 150, 200, 250, 300, 350, 400, 450, 500, 600, 700, 800, 900, or 1000°C. Combinations of these temperature values, for example, about 300°C to about 400°C, for example, about 350°C, are also possible.

[0179] In some embodiments, at least a portion of the coordinating organic linker is removed by thermal decomposition of the layered metal-coordinating polymer. In some embodiments, the thermal decomposition is low-temperature thermal decomposition. In other embodiments, the thermal decomposition is carried out at a temperature of at least 100, 150, 200, 250, or 300°C.

[0180] Other possible treatments for forming nanostructures include X-ray irradiation, cold laser irradiation, gamma-ray irradiation, neutron irradiation, and other suitable high-energy beam irradiation capable of forming nanostructures from metal-coordinated polymers.

[0181] In some embodiments, removing at least a portion of the coordinating organic linker to form nanostructures involves aging a solution containing a layered metal coordination polymer. The solution containing the metal coordination polymer is sonicated or agitated during the aging process. Alternatively, the solution may remain static during the aging process.

[0182] Aging of the solution may occur at a basic pH (e.g., a low acidic pH, e.g., using a solution concentration of up to 6.0 M NaOH). In some embodiments, aging of a solution containing a layered metal coordination polymer occurs at a basic pH greater than pH 7, e.g., at least about pH 7, 8, 9, 10, 11, 12, 13, or 14, preferably pH 8. Combinations of these pH ranges, e.g., about pH 7 to pH 14, or about pH 7 to about pH 10, e.g., pH about 8, are also possible.

[0183] Aging of the solution at a basic pH may further include a stirring step. The stirring step may be performed simultaneously with the aging of the solution at a basic pH. Aging of the solution at a basic pH may include raising the pH of the solution containing the metal coordination polymer by adding a basic pH, for example, a suitable base, for example, sodium hydroxide. Alternatively, the solution may have its pH adjusted before the addition of the metal coordination polymer. In one embodiment, the step of removing one or more organic linkers includes raising the pH of the solution. The solution may be stirred while raising the pH.

[0184] In some embodiments, the aging of the solution containing the layered metal coordination polymer is a certain period of time effective for forming nanostructures, for example, at least about 1 minute, 15 minutes, 30 minutes, 1 hour, 2 hours, 6 hours, 12 hours, 1 day, or 2 days. In some embodiments, the aging of the solution is a certain period of time from about 1 minute to about 2 days, preferably from about 10 minutes to about 2 hours, for example, about 30 minutes.

[0185] In some embodiments, the aging of the solution is at a temperature effective for forming nanostructures, for example, at least about 1, 5, 10, 15, 20, 30, 40, 50, 70, or 100°C, and combinations thereof, for example, about 10°C to about 50°C, preferably room temperature, for example, about 25°C.

[0186] Aging may involve a heating or combustion process. The heating or combustion process may involve heating or burning a solution containing a metal-coordinate polymer. The heating or combustion of the solution may be at temperatures of at least about 10, 20, 25, 30, 40, 50, 80, 100, 150, 200, 250, 300, 350, 400, 450, 500, 550, or 600°C. The heating or combustion of the solution may be at temperatures of about 600, 550, 500, 450, 400, 350, 300, 250, 200, 150, 100, 80, 50, 40, 30, 25, 20, or below 10°C. Combinations of these heating or combustion temperatures, for example, about 10°C to about 50°C, about 50°C to about 600°C, about 100°C to about 600°C, or about 200°C to about 600°C, are also possible.

[0187] The morphology of the nanostructure can change depending on the heating or burning rate. The heating or burning rate is at least about 0.01, 0.05, 0.1, 0.2, 0.3, 0.5, 1.0, 1.5, 2.0, 2.5, 3.0, 3.5, 4.0, or 5.0°C. -1 It is possible. The heating or burning rate is approximately 5.0, 4.0, 3.5, 3.0, 2.5, 2.0, 1.5, 1.0, 0.5, 0.3, 0.2, 0.1, 0.05, or 0.01°C. -1It may be less than these. These combinations of heating or combustion rates, for example, about 0.1 to about 5 degrees Celsius -1 Or approximately 0.2 to 3 degrees Celsius -1 It is also possible. Heating or burning may be carried out for a suitable period of time, for example, at least about 1 minute, 15 minutes, 30 minutes, 1, 2, 3, 4, 8, 12, 18, 24, 48, or 72 hours.

[0188] The aging solution can be heated up to the boiling point of the solution. In one embodiment, the aging solution can be heated to a temperature of 100°C to 300°C, for example, about 200°C.

[0189] In some embodiments, metal atoms are destabilized by the removal of at least a portion of the coordinating organic linker, thereby sequentially forming stable nanostructures. In some embodiments, when at least a portion of the coordinating organic linker is removed, the metal coordination polymer is transformed (e.g., spontaneously or by application such as heating or stirring) to form stable nanostructures. In some embodiments, the morphology of the nanostructure is the same as that of the metal coordination polymer.

[0190] As a result of the removal of at least a portion of the coordinating organic linker, the resulting nanostructure may be a porous nanostructure. The step of removing at least a portion of the coordinating organic linker to form a more stable metal-based species (e.g., uncoordinated metal atomic centers / substructures) forms a porous nanostructure. Thus, in some embodiments, the nanostructure is a porous oxide nanostructure, and the step of removing at least a portion of the coordinating organic ligand forms a porous nanostructure. In some embodiments, the nanostructure exhibits a fine and homogeneous pore network. The terms “nanostructure” and “porous nanostructure” may be used interchangeably throughout this disclosure unless the context clarifies otherwise. For example, references to pore size are made in reference to porous nanostructures.

[0191] Reactive metal-based species form part of a metal-coordinate polymer. Since reactive metal-based species are stabilized by a coordinating organic linker, they can exist in a "reactive" state while coordinated to the organic linker. In some embodiments, removal of the organic linker allows an unstable metal-based species to be applied to a more stable state (i.e., a more stable metal-based species) after the organic linker is removed. For example, a reactive metal-based species can be a polyvalent metal, where the polyvalent ion is in a first oxidation state in the reactive or unstable state, and in a second oxidation state in the stable state. For example, the metal in a reactive metal-based species may have a first oxidation state when bound to a ligand, and a second oxidation state when the ligand is removed. In some embodiments, the metal in a reactive metal-based species is a polyvalent metal. Reactive metal-based species may include metals having two or more oxidation states. In some embodiments, the metal atom is selected from one or more metal atoms (including ions) as described herein, for example, Ce, Cu, Mn, Fe, Ni, Zn, Ti, or Zr. In some embodiments, the metal atom is Ce, Ti, or Zr. In some embodiments, the metal ion is Ce(IV), Ti(IV), or Zr(IV).

[0192] In some embodiments, the method involves providing a layered metal coordination polymer having many metal ions. In some embodiments, the metal ions are monovalent or polyvalent, preferably polyvalent.

[0193] In some embodiments, the metal may have a low field intensity in a low oxidation state within a viable working pH range for forming a metal coordination polymer. In some embodiments, the metal atom has an oxidation state that can increase when oxidized at an acidic pH. The working pH range can be determined by a Poole-Bay diagram. The oxidation state of the metal at the reactive metal center may increase when oxidized at an acidic pH. In some embodiments, an unsaturated metal hydroxide (M(OH)) x n+ ) can form an acidic pH under high oxidation conditions.

[0194] For example, in some embodiments, when the ligand is removed, the reactive metal-based species may form an unsaturated metal hydroxide as an unstable metal-based species, which is then converted to a more stable metal oxide. Removal of at least a portion of the organic linker may cause the reactive metal-based species to form an unstable metal oxide-based species. In aqueous systems, the unstable metal oxide-based species may include hydroxide salts and peroxide salts. In non-aqueous systems, other metal oxide-based species may be formed. As an example, when Ce is used as the metal of a reactive metal species while coordinated to an organic linker, removal of the organic linker may result in the formation of an unstable metal-based species such as Ce(OH) x (4-x)+ This can promote the formation of, and then, as a more stable metal-based species that forms porous nanostructures, CeO 2-x Convert to.

[0195] In some embodiments, the conversion from metal coordination polymers to metal oxides occurs in aqueous solution of OH - This is due to the substitution of weakly bonded organic linkers by / H2O. For example, in Ce-based coordination polymers in aqueous solution, Ce 4+ The relatively high field strength enhances its ability to form Ce(OH)4, and when drying, CeO 2-x It is easily converted. The conversion from a reactive metal-based species to a more stable metal-based species can occur at room temperature (e.g., <35°C). In some embodiments, a heating step is used to convert from a reactive metal-based species to a more stable metal-based species.

[0196] In some embodiments, the layered metal coordination polymer is exfoliated to obtain a dispersion of the metal coordination polymer layer before removing at least a portion of the coordinating organic linker that forms the nanostructure. In some embodiments, the layer may be formed as a sheet of metal coordination polymer, and exfoliation results in the formation of a dispersion of discrete sheets.

[0197] In some embodiments, removing at least a portion of the organic linker from the dispersion of discrete sheets can lead to the formation of a dispersion of porous nanosheets. Alternatively, removing at least a portion of the organic linker can form a species capable of forming pores.

[0198] In some embodiments, the steps of exfoliating the layered material and removing at least a portion of the coordinated organic linker are performed simultaneously. If the layered material is not exfoliated before ligand removal, and regardless of the mechanism used to form the porous nanostructure, each sheet may still be converted into a porous nanosheet, but it should be noted that the pores of each nanosheet do not have to be aligned with each other, and the appearance of a structure that is not "porous" but is "porous" at the nanolevel may be given. The layered material does not have to be planar. In some embodiments, the layered material may be formed in the shape of a tube or rod. For example, the layers may wrap around the central axis of the layered material.

[0199] Exfoliation may be carried out, for example, by stirring, as described herein. In some embodiments, the metal coordination polymer is dispersed in a suitable solvent (e.g., water) and stirred for a period of time effective in exfoliating the metal coordination polymer to obtain a dispersion of the metal coordination polymer layer before removing at least a portion of the coordination ligands, thereby forming a nanostructure. Suitable solvents may include water, a polar protic solvent, or a polar aprotic solvent. Polar aprotic solvents may include dichloromethane, NMP, THF, acetate, acetone, DMF, acetonitrile, or DMSO. Polar protic solvents may include water, alcohols (e.g., ethanol and methanol), and carboxylic acids.

[0200] In some embodiments, the metal coordination polymer is preferably stirred for a set period of at least about 1 minute, 2 minutes, 5 minutes, 8 minutes, 10 minutes, 15 minutes, 30 minutes, 1 hour, 2 hours, 6 hours, 12 hours, 1 day, or 2 days to exfoliate the metal coordination polymer and obtain a dispersion of the metal coordination polymer layer and / or nanostructure. Combinations of these stirring times are also possible. For example, the metal coordination polymer is stirred for a set period of about 1 minute to about 2 days, preferably about 10 minutes to about 2 hours, for example, about 30 minutes, to exfoliate the metal coordination polymer and obtain a dispersion of the metal coordination polymer layer. Exfoliation may be assisted by chemical means. Exfoliation may also include heating and / or sonication. The exfoliation step may be at a basic pH, for example, as described herein, with respect to the removal of one or more organic linkers. The exfoliation step and the aging step may be performed simultaneously.

[0201] In the embodiment, Rayville The ions are scattered between the metal-coordinate polymer layers as described herein. For example, if the organolinker contains terminal acidic groups, Rayville The ions can be acid protons and can be intercalated between sheets. Intercalated protons can help hold the layered material together. For example, protons can act as weak crosslinking agents. In some embodiments, the delamination step of the layered material includes removing the intercalated protons. For example, an alkaline pH can be used to remove the intercalated protons. Generally, the removal of intercalated protons occurs at the edges of the layered material, which weakens the van der Waals forces that hold the layers together, allowing water molecules to penetrate between adjacent sheets. The propagation front of proton removal and water penetration then proceeds from the edges towards the interior of the layered structure. Thus, in embodiments, water penetration causes delamination. However, delamination is not limited to water penetration and can be accelerated by, for example, adjusting the temperature, chemical environment, etc.

[0202] Layered structures can have many different architectures. In some embodiments, the structure (architecture) of the layered structure may change before the removal of at least some of the ligands. During the change in the layered structure, the reactive metal-based species may remain unchanged. The architecture of the layered material may be preserved when ligands are removed and the reactive metal-based species are converted to more stable metal-based species. In some embodiments, the structure of the sheet does not change during the conversion from reactive metal-based species to more stable metal-based species. It should be understood that while the structure may change at the atomic level, at the macro level, the architecture of the nanostructure (e.g., nanosheet) remains unchanged, for example, remaining a two-dimensional sheet. Changes in the architecture of the layered material (i.e., the precursor material) may enable the formation of different nanostructures from a single precursor layered material.

[0203] In some embodiments, the architecture of the layered material can be altered by decomposing the layered material in different solvent systems, as described herein. For example, in strongly polar solvents such as water, the layered material may be preferentially exfoliated rather than altering its architecture. When using less polar solvents such as ethanol, the layers can be differentiated and then reconstructed. Thus, in some embodiments, the metal-coordinating polymer is decomposed in an organic solvent and reconstructed from the organic solvent by evaporation, altering the morphology of the metal-coordinating polymer before or during the removal of one or more organic linkers, thereby forming the nanostructure. In this way, tailored and unique nanostructure morphologies can be formed.

[0204] The method for reconstructing the layers may depend on the concentration of the layered material, the type of solvent, the use of a solvent system such as a gradient solvent system, the evaporation rate, heating, cooling, pH, and the introduction of groups that cause stratification, such as salts.

[0205] In some embodiments, the concentration of the metal-coordinate polymer that is decomposed in the organic solvent is limited by the maximum solubility of the metal-coordinate polymer in the organic solvent, and is preferably about 4 M to about 120 M.

[0206] In some embodiments, the evaporation of the organic solvent is carried out at a temperature and vapor pressure limited by the maximum solubility of the organic solvent in air, preferably about -20°C to about 40°C, more preferably about -10°C to about 25°C, and a vapor pressure of about 0.1 kPa to about 10 kPa, preferably about 0.5 kPa to about 8 kPa.

[0207] In some embodiments, the organic solvent is an alcohol, such as methanol, ethanol, propanol, butanol, pentanol, and preferably ethanol. In some embodiments, the organic solvent is a polar aprotic solvent and may include dichloromethane, NMP, THF, acetate, acetone, DMF, acetonitrile, or DMSO. In some embodiments, the organic solvent is an amine, such as triethylamine. In some embodiments, the organic solvent is acetone.

[0208] The step of removing at least a portion of the coordinating organic linker may include (i) increasing the affinity of the metal for conversion to an oxidized form, for example, to form a more stable metal-based species, and / or (ii) decreasing the affinity of the organic linker to the reactive metal moiety. These can be achieved by changing the environment of the metal-coordinating polymer, for example, by adjusting the solvent, salt concentration, temperature, pH, and / or introduction of the active material that breaks the linker's bond to the reactive metal-based species. In embodiments, decreasing the affinity of the linker to the reactive metal-based species includes increasing the pH of the mixture containing the nanostructure. For example, if the linker contains an acidic group such as a carboxyl group, increasing the pH of the solution in which the metal-coordinating polymer is present changes the affinity of the carboxyl group by deprotonating the carboxyl group and promoting the formation of a reactive metal intermediate.

[0209] In some embodiments, reducing the affinity of the linker to the reactive metal-based species involves heating the metal-coordinating polymer. For example, a combination of processes such as changes in pH and temperature may be used to reduce the affinity of the bond between the reactive metal-based species and the coordinating organic linker.

[0210] In some embodiments, this is due to weak electrostatic bonding between cations (e.g., metal ions) and organic linkers (e.g., organic linkers containing organic acids) in an unstable coordination polymer. Lability This includes nanostructures that had not been observed before, such as CeO 2-x This provides a valuable platform for easily and controllably disrupting and reconstructing coordination polymer crystallites to form nanostructures.

[0211] The nanostructures used in the preparation of the metal-coordinate polymer may be the metal-coordinate polymer as described herein, or may be the metal-coordinate polymer prepared by the process described herein.

[0212] nanostructures The nanostructures that can be generated by this method are diverse. In some embodiments, this disclosure provides nanostructures. In some embodiments, the nanostructures exhibit a fine and homogeneous pore network. In some embodiments, the nanostructures are bulk nanostructures.

[0213] The morphology of nanostructures can be sheet-like, hollow, porous, cubic, rod-like, polyhedral, spherical or hemispherical, round or semi-round, angular, and irregular morphologies, as well as tubular, dumbbell-shaped, rhombohedral, honeycomb, needle-like, bundle-like, wafer-like, fibrous, and floral structures, and may also include two-dimensional and / or three-dimensional scaffold structures containing the same. The morphology of nanostructures may correspond to the morphology of layered nanostructures used in the preparation of metal-coordinate polymers.

[0214] In some embodiments, the nanostructure is polycrystalline. In some embodiments, the nanostructure is solid and / or hollow. Hollow nanostructures may be faceted. Nanostructures may be porous nanostructures. By removing at least a portion of the organic linker, reactive metal centers can form porous nanostructures.

[0215] In some embodiments, the nanostructure is a metal oxide. The metal oxide may be an oxide of any metal described herein with respect to metal coordination polymers.

[0216] In some embodiments, the nanostructure is a nanosheet or nanolayer. For example, a nanosheet is formed by exfoliating a metal coordination polymer to form one or more metal coordination polymer layers, then aging and removing one or more organic linkers therefrom. The nanosheet can be solid or hollow. In one embodiment, the nanosheet is a metal oxide.

[0217] In one embodiment, the nanosheet is a porous nanosheet. In one embodiment, the nanosheet is a porous metal oxide nanosheet, for example, a porous CeO 2-x These are nanosheets, where x can vary between 0 and 0.9, 0 and 0.8, 0 and 0.7, 0 and 0.6, and 0 and 0.5. The porous metal oxide nanosheets may be porous FCO nanosheets, porous NCO nanosheets, or porous ZCO nanosheets.

[0218] In one embodiment, the nanostructure is a bulk metal oxide nanostructure. The bulk metal oxide nanostructure may be porous. The bulk metal oxide nanostructure may be one-dimensional, two-dimensional, or three-dimensional. The bulk nanostructure may be solid or hollow.

[0219] In one embodiment, the nanostructure is a porous metal oxide nanosheet. The nanosheet may have an average pore diameter of at least about 1, 2, 3, 4, 5, 8, 10, 12, 14, 18, or 20 nm. The nanosheet may have an average pore diameter of less than about 20, 18, 14, 12, 8, 5, 4, 3, 2, or 1 nm. Any combination of two or more of these upper and / or lower diameter limits, for example, about 2 nm to about 20 nm, or for example, 2 nm to about 14 nm, is also possible. The pore diameter can be measured using transmission electron microscopy.

[0220] In some embodiments, the nanostructure is a metal oxide nanosheet having a concentration of point defects (e.g., cation vacancies and / or anion vacancies). The concentration of point defects may depend on the type of metal oxide nanostructure and / or the morphology of the metal coordination polymer used to prepare the metal oxide nanostructure. In some embodiments, the metal oxide nanosheet has a defect concentration of at least about 1, 2, 5, 10, 12, 14, 18, 20, 25, 30, 35, or 40 atomic percent. In some embodiments, the metal oxide nanosheet has a defect concentration of less than about 40, 35, 30, 25, 20, 18, 14, 12, 10, 5, 2, or 1 atomic percent. Any combination of two or more of these upper and / or lower limit defect concentrations, e.g., about 1 to about 30 atomic percent, e.g., 18 to about 30 atomic percent, is also possible.

[0221] Nanostructures may have a specific surface area (BET). The specific surface area is at least about 25, 50, 75, 85, 95, 100, 200, 500, or 1000 m². 2 It can be / g. The specific surface area is approximately 1000, 500, 200, 100, 95, 85, 75, 50, or 25 m². 2 It may be less than / g. The specific surface area is at least about 70, 75, 80, 85, 90, 95, 100 m². 2 It can be / g. Any two or more combinations of these upper and / or lower limits of specific surface area, for example, about 75 to about 1000 m 2 / g is also possible.

[0222] Nanostructures can be polycrystalline. Polycrystalline nanostructures may contain one or more crystallites. The average crystallite size may be less than 100, 80, 60, 50, 40, 30, 20, 15, 10, or 5 nm. The average crystallite size may range from approximately 1 nm to approximately 20 nm.

[0223] Nanostructures can be nanolayers, such as nanosheets. Nanosheets can be porous nanosheets. Nanosheets can have a specific thickness (e.g., cross-sectional distance) along the layer or sheet (referred to as axial thickness along the c-axis of the sheet or layer). In some embodiments, nanosheets can have axial thicknesses along the c-axis of 100, 70, 50, 20, 15, 10, 8, 6, 4, 2, or less than 1 nm, for example, 20, 15, 12, 10, 8, 5, 2, or less than 1 nm. Combinations of any two or more of these upper and / or lower thickness limits, for example, about 1 nm to about 100 nm, about 1 nm to about 50 nm, or about 1 nm to about 20 nm are also possible.

[0224] The nanosheets may be porous nanosheets, and the average pore diameter may be at least about 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 15, 20, 50, 80, or 100 nm. The nanosheets may be porous nanosheets, and the average pore diameter may be less than about 100, 80, 50, 20, 15, 10, 9, 8, 7, 6, 5, 4, 3, 2, or 1 nm. Any combination of two or more of these upper and / or lower average pore diameters, for example, about 1 nm to about 50 nm, or about 2 nm to about 14 nm, is also possible.

[0225] In one embodiment, a porous ceria nanosheet is provided. The porous ceria nanosheet may have an axial thickness of 100, 70, 50, 20, 15, 10, 8, 6, 4, 2, or less than 1 nm, for example, 20, 15, 12, 10, 8, 5, 2, or less than 1 nm. Combinations of two or more of these upper and / or lower thickness limits, for example, about 1 nm to about 100 nm, about 1 nm to about 50 nm, or about 1 nm to about 20 nm are also possible.

[0226] In one embodiment, the nanosheet has an axial thickness of approximately 1.1, 2.2, 5.5, or 11 nm, and the thickness is proportional to the thickness of one unit cell of the metal-coordinate polymer. In some embodiments, the nanosheet may have a unit cell thickness of approximately 1, 2, 3, 4, 5, 6, 7, 8, 9, or 10. The thickness can be measured using scanning electron microscopy or atomic force microscopy (AFM).

[0227] In some embodiments, the nanostructure may consist of a number of individual layers, which are stacked to form individual nanolayers. In some embodiments, the individual nanolayers are stacked to form a bulk nanostructure. In some embodiments, the nanostructure is a metal oxide nanosheet, and two or more metal oxide nanosheets are stacked to form a bulk metal oxide nanostructure. In some embodiments, the nanostructure is a porous metal oxide nanosheet, and multiple nanosheets are stacked to form a stacked nanostructure.

[0228] In some embodiments, the morphology of the nanostructure is the same as that of the nanostructure used to prepare the metal-coordinate polymer. For example, if the metal-coordinate polymer is a hollow nanotube, the nanostructure obtained after the removal of one or more organic linkers as described herein may also be a hollow nanotube.

[0229] Heterojunction nanostructures Heterojunctional nanostructures can also be prepared using the metal coordination polymers described herein, where one or more adsorbed species may be adsorbed onto the surface of the nanostructure. The adsorbed species may be a second metal species. By adsorbing the second metal species onto the surface, a metal-functionalized nanostructure can be formed. The nanostructure can act as a template.

[0230] Adsorbed species are adsorbed onto a surface by being dispersed in a solution or dispersion containing the species. Adsorbed species can be adsorbed both in pores and on the surface. If the nanostructure is a porous nanostructure, the surface charge of the porous nanostructure can create an attractive force that causes adsorbed species to be adsorbed. For example, a porous nanostructure may have a negative zeta potential, and positive metal ions may be attracted to the surface of the porous nanostructure and uniformly adsorbed onto its surface.

[0231] In some embodiments, one or more adsorbed species are adsorbed onto the surface of the nanostructure, forming one or more heterojunctions on the surface of the nanostructure.

[0232] In some embodiments, one or more species are adsorbed onto the surface of the nanostructure by removing at least a portion of the organic linker in the presence of the adsorbed species.

[0233] Adsorbed species can be aged in the presence of a metal coordination polymer. For example, adsorbed species can be added to an aging solution containing a metal coordination polymer, or they can be aged in a solution containing a metal coordination polymer. In some embodiments, when the solution has a pH of about 3 to about 7, the adsorbed species are mixed with an aging solution containing a metal coordination polymer.

[0234] Preferably, the adsorbed species includes one or more metal atoms different from the metal atoms of the metal coordination polymer. Alternatively, the adsorbed species may be the same metal as the metal atoms of the metal coordination polymer, but may have a different valency.

[0235] The adsorbed species may be in ionic form. More preferably, the adsorbed species may be metals, nonmetals, metalloids, or metalloids, or combinations thereof, for example, their elements, ionic forms, oxides, or non-oxides, preferably, for example, S, C, N, C, As, Te, O, Se, P, Mn, Fe, Ni, Cu, Zn, Mo, and Ru, for example, mixtures thereof. The adsorbed species may also be, for example, a metal-based species, which is oxidized after adsorption onto the surface of the nanostructure. Alternatively, once adsorbed, the metal species may be element M 0It can be reduced to a morphological form. The nanostructure can be doped with one or more adsorbed species described herein.

[0236] In the embodiment, once adsorbed species are adsorbed onto the surface of the nanostructure, oxidation conditions, including combustion with an oxidizing agent and chemical oxidation, are applied to the nanostructure. The adsorbed species can help alter the catalyst, electrode potential, pore size (if the nanostructure is a porous nanostructure), and / or selectivity properties of the nanostructure, for example, to allow selected species to pass through the pores of a porous nanosheet.

[0237] In some embodiments, a solution containing a metal coordination polymer is aged in the presence of one or more adsorbed species to form one or more heterojunctions on the surface of the nanostructure. For example, one or more adsorbed species may be dissolved or suspended in the solution containing the metal coordination polymer (which is aged to form one or more heterojunctions on the surface of the nanostructure). Alternatively, the adsorbed species may be part of the organic solvent used to prepare the solution containing the metal coordination polymer. For example, the metal coordination polymer may be decomposed in an organosulfosol (e.g., DMSO), which is then reconstructed, aged, and mixed to form metal oxide / sulfide nanostructures.

[0238] In some embodiments, the nanostructure may be a metal oxide, metal sulfide, metal arsenide, metal selenide, metal telluride, metal phosphide, metal nitride, or metal carbide, or a mixture thereof. In one embodiment, a metal coordination polymer may be used as a precursor for forming a hybrid nanostructure containing sulfur and / or carbon. In one embodiment, the nanostructure is a mixed ceria sulfide carbide.

[0239] Furthermore, nanostructures comprising porous nanosheets having a metal oxide are disclosed. The nanosheets may have a unit cell thickness of less than 30. The pores may arise from the removal of ligands bound to reactive metal-based species that form the metal oxide.

[0240] The thickness of the nanosheet may be less than 5 unit cells, for example, 2 unit cells. The thickness may be 1 unit cell thickness. The thickness of the nanosheet in nanometers (nm) may depend on the size and number of unit cells. In embodiments, the nanostructure has a defect concentration of approximately 18-30 atomic percent.

[0241] Nanosheets may be formed from metal-coordinate polymers as described herein. Nanosheets may have the same morphology and / or structure as the metal-coordinate polymers. Nanostructures may comprise multiple porous nanosheets. For example, multiple porous nanosheets may be stacked to form a layered structure. When a nanostructure has multiple porous nanosheets, the pores of adjacent sheets may be aligned with each other. However, in some embodiments, the pores of adjacent sheets may not be aligned with each other. When the pores of adjacent sheets are not aligned with each other, the nanostructure may not appear to have pores at a macroscopic level.

[0242] Metal oxides can be oxides of polyvalent metals. The metal in a metal oxide can be a polyvalent metal. The metal in a metal oxide can have a high coordination number. Metal oxides can include oxides of Ce, Cu, Mn, Fe, Ni, Ti, Zr, and Zn. The surface of a nanosheet can be decorated with a second metal-based species (i.e., heterojunction, plasma resonance). The second metal-based species can include a mixture of metal-based species, e.g., a mixture having two or more metal-based species. The second metal base can be in ionic, metallic, or / or oxide form. The electrode potential properties of the nanosheet can be prepared through the inclusion of the second metal.

[0243] The nanostructure may be a mixed cerium oxide. The mixed cerium oxide may contain one or more oxides of Cu, Mn, Fe, Ni, Ti, Zr, and Zn. The mixed cerium oxide may be FCO, NCO, or ZCO.

[0244] Porous nanosheets may have a surface charge of less than zero (0) mV. In some embodiments, porous nanosheets may have zeta potentials of less than approximately 0, -5, -10, -15, -20, -25, -30, -40, -50, -80, or -100 mV. Combinations of these zeta potentials, for example, from about -10 mV to about -40 mV, are also possible.

[0245] In some embodiments, once an adsorbed species (e.g., a second metal-based species) is adsorbed onto the surface of a nanostructure, the adsorbed species is subjected to a structural transformation by O, N, S, Se, or Te.

[0246] catalyst composition The nanostructures described herein have one or more catalytic properties. Therefore, in one embodiment, a catalytic composition comprising a nanostructure is provided according to any embodiment or example thereof, as described herein. The nanostructure can be used as a catalyst. In one embodiment, a method for catalyzing a reaction using a nanostructure or its catalytic composition is provided according to any embodiment or example thereof, as described herein. The reaction may be an oxidation reaction. The nanostructure or its catalytic composition can catalyze the oxidation of one or more reactants. The reaction may involve the oxidation of one or more contaminants or impurities present in an aqueous or gaseous environment.

[0247] In some embodiments, a method is provided for purifying a gaseous stream or atmosphere (e.g., air) by contacting the gaseous stream or atmosphere with a nanostructure or its catalytic composition, wherein one or more contaminants or impurities present in the gaseous stream or atmosphere are catalytically reacted (e.g., oxidized) upon contact with the nanostructure or its composition. The gaseous stream or atmosphere may contain carbon monoxide. The nanostructure or its catalytic composition can oxidize carbon monoxide to carbon dioxide. In one embodiment, a method is provided for purifying a gaseous stream or atmosphere containing carbon monoxide, comprising contacting the gaseous stream or atmosphere with a nanostructure or its catalytic composition to oxidize carbon monoxide to carbon dioxide, according to any embodiment or example described herein. The gaseous stream or atmosphere may be an exhaust stream (e.g., industrial flue gas or vehicle exhaust).

[0248] In some embodiments, a composition containing nanostructures or the same can achieve complete CO oxidation (e.g., to CO2) (i.e., 100% CO oxidation) at temperatures below about 200, 190, 180, 170, 160, 150, 140, 130, 120, 110, 100, 90, or 80°C, for example, at temperatures between about 80°C and about 200°C. In some embodiments, a composition containing nanostructures or the same can achieve 50% CO to CO2 oxidation at temperatures below about 200, 190, 180, 170, 160, 150, 140, 130, 120, 110, 100, 90, or 80°C, for example, at temperatures between about 80°C and about 200°C.

[0249] In some embodiments, the nanostructure or its composition is at least about 1, 2, 5, 7, 10, 12, 15, or 20 mol g -1 s -1 The CO → CO2 conversion rate at 400°C, and / or at least about 1, 2, 3, 4 or 5 × 10 -3 mol mol -1 s -1It has a CO→CO2 turnover frequency (TOF). Combinations of these catalytic properties are also possible, and for example, in some embodiments, the nanostructure or its composition is about 1 to 20 mol g -1 s -1 The CO to CO2 conversion rate at 400°C, and / or approximately 1 to approximately 5 × 10 -3 mol mol -1 s -1 It has a CO→CO2 turnover frequency (TOF). In some embodiments, the nanostructure or its composition has a CO→CO2 conversion rate according to the performance provided in Figure 64.

[0250] Using the nanostructure or its composition, a water stream (e.g., water) can be purified by contacting the water stream with the nanostructure or its catalytic composition, according to any embodiment or example described herein, and one or more contaminants or impurities present in the water stream are catalytically decomposed (e.g., oxidized) upon contact with the nanostructure or its composition.

[0251] The catalyst composition may or may consist of a nanostructure and optionally one or more additives. Suitable additives may include one or more inert materials to enhance catalytic activity, such as binders and fillers, and / or one or more catalyst accelerators.

[0252] The catalyst composition may be provided as any suitable composition. In one embodiment, the catalyst composition may be a coating composition. The coating composition may be applied to a surface or substrate, for example, quartz wool. Additional additives, such as binders, may facilitate coating of the catalyst composition onto the surface. The catalyst composition or its coating may be provided as a partial coating or a complete layer on a surface. The catalyst composition may be deposited on a surface by brush coating, painting, slurry spraying, spray pyrolysis, dipping coating, ink printing, sputtering, chemical or physical vapor deposition techniques, electroplating, screen printing, or tape molding.

[0253] In embodiments, the nanostructures packed into the catalyst composition may be 90% by weight, 80% by weight, 70% by weight, 60% by weight, 50% by weight, 40% by weight, 30% by weight, 20% by weight, 18% by weight, 16% by weight, 14% by weight, 12% by weight, 10% by weight, 8% by weight, 6% by weight, 4% by weight, or less than 2% by weight. The catalyst packing may be at least 1% by weight, 3% by weight, 5% by weight, 7% by weight, 9% by weight, 11% by weight, 13% by weight, 15% by weight, 17% by weight, 10% by weight, 20% by weight, 30% by weight, 40% by weight, 50% by weight, 60% by weight, 70% by weight, 80% by weight, or 90% by weight. In one embodiment, the catalyst consists of nanostructures.

[0254] This disclosure may also be defined by reference to one or more of the following numbered paragraphs:

[0255] 1. A method for forming nanostructures, To provide a metal-coordinate polymer having many reactive metal-based species that coordinate to one or more ligands; and By removing at least a portion of the coordinated ligand, the reactive metal-based species can form a more stable metal-based species, thereby forming the nanostructure. The method, including the method described above.

[0256] 2. The method according to paragraph 1, wherein removing at least a portion of the ligand increases the pH of the mixture containing the nanostructure.

[0257] 3. The method according to paragraph 1 or 2, wherein removing at least a portion of the ligand involves heating the metal-coordinate polymer.

[0258] 4. The method according to any one of paragraphs 1 to 3, wherein the ligand has a single binding site.

[0259] 5. The method according to any one of paragraphs 1 to 4, wherein the ligand comprises a carboxyl group.

[0260] 6. The method according to any one of paragraphs 1 to 5, wherein the metal coordination polymer can form a sheet, and a plurality of sheets can be assembled to form a layered material.

[0261] 7. The method according to paragraph 6, wherein the layered material is peeled off to form a dispersion of discrete sheets before removing at least a portion of the coordinated ligand.

[0262] 8. The method according to paragraph 7, wherein the step of peeling off the layered material and removing at least a portion of the coordinated ligand is performed simultaneously.

[0263] 9. Rayville The process involves intercalating ions between the laminated sheets and peeling off the layered material. Rayville The method according to paragraph 7 or 8, comprising removing ions.

[0264] 10. The method according to any one of paragraphs 6 to 9, further comprising altering the structure of the layered material before removing at least a portion of the coordinated ligand, wherein the reactive metal-based species remains unchanged during the alteration of the structure of the layered material.

[0265] 11. The method according to any one of paragraphs 1 to 10, wherein the step of providing the metal coordination polymer comprises forming the metal coordination polymer, and forming the metal coordination polymer comprises mixing a first metal atom with a ligand, wherein the metal of the first metal atom is the same as the metal in the reactive metal base species.

[0266] 12. The method according to paragraph 11, wherein the step of forming the metal coordination polymer includes electrodeposition.

[0267] 13. The method according to paragraph 11, wherein the step of forming the layered material includes heating the solution of the metal atoms and ligand.

[0268] 14. The method according to any one of paragraphs 1 to 13, wherein the metal of the reactive metal-based species is polyvalent.

[0269] 15. The method according to any one of paragraphs 1 to 14, wherein the reactive metal-based species forms an unstable metal oxide-based species upon removal of the ligand.

[0270] 16. The method according to paragraph 15, which converts the unstable metal oxide base species into a more stable metal oxide.

[0271] 17. The method according to any one of paragraphs 1 to 16, further comprising adsorbing a second metal-based species onto the surface of a nanostructure.

[0272] 18. The method according to paragraph 17, wherein the second metal-based species is adsorbed onto the surface of the nanostructure by removing at least a portion of the coordinated ligand in the presence of the second metal.

[0273] 19. The method according to paragraph 17 or 18, wherein the second metal base is different from the more stable metal base species.

[0274] 20. The method according to any one of paragraphs 17-19, wherein the second metal-based species is an ionic form of a metal, a nonmetal, a metalloid, and / or a metalloid, as well as forms of oxides and nonoxides.

[0275] 21. The method according to any one of paragraphs 17 to 20, wherein the second metal base species includes Cu, Ni, Fe, and Zn.

[0276] 22. The method according to any one of paragraphs 17 to 21, wherein the second metal-based species is oxidized when it is adsorbed onto the surface of the nanostructure.

[0277] 23. The method according to any one of paragraphs 1 to 22, wherein the reactive metal-based species forms the more stable metal-based species at room temperature.

[0278] 24. The method according to any one of paragraphs 1 to 23, wherein the structure of the metal coordination polymer does not change during the formation of the more stable metal-based species.

[0279] 25. The method according to any one of paragraphs 1 to 24, wherein the nanostructure is a porous nanostructure, and the step of removing at least a portion of the coordinated ligand and forming the reactive metal-based species into a more stable metal-based species is the method for forming the porous nanostructure.

[0280] 26. The method according to any one of paragraphs 1 to 25, wherein the nanostructure is polycrystalline.

[0281] 27. The method according to any one of paragraphs 1 to 26, wherein the nanostructure is solid and / or hollow.

[0282] 28. Nanostructures prepared using the method described in any one of paragraphs 1 to 27.

[0283] 29. A nanostructure comprising a nanosheet having a metal oxide, wherein the nanosheet is obtained by removing a ligand that binds to a reactive metal-based species that proceeds to the formation of the metal oxide.

[0284] 30. The nanostructure according to paragraph 29, wherein the thickness of the nanosheet is less than 5 units.

[0285] 31. The nanostructure according to paragraph 30, wherein the thickness is 2 unit cells or less.

[0286] 32. The nanostructure according to any one of paragraphs 29 to 31, wherein the metal oxide comprises an oxide of Ce.

[0287] 33. The nanostructure according to any one of paragraphs 29 to 32, wherein the nanosheet is a porous nanosheet.

[0288] 34. The nanostructure according to paragraph 33, wherein the diameter of the pores is in the range of approximately 2 nm to 14 nm.

[0289] 35. The nanostructure according to any one of paragraphs 29 to 34, wherein the nanosheet has a defect concentration of approximately 18 to 30 atomic percent.

[0290] 36. A nanostructure according to any one of paragraphs 29 to 35, comprising a plurality of the nanosheets, wherein the plurality of nanosheets are stacked to form a stacked structure.

[0291] 37. The nanostructure according to any one of paragraphs 29 to 36, wherein the nanostructure is formed from a metal coordination polymer precursor, and the structure of the nanostructure is the same as that of the metal coordination polymer precursor.

[0292] 38. The nanostructure according to any one of paragraphs 29 to 37, wherein the nanostructure is polycrystalline.

[0293] 39. The nanostructure according to any one of paragraphs 29 to 38, wherein the nanostructure is solid and / or hollow.

[0294] 40. A catalyst comprising any one of the nanostructures described in paragraphs 28-39.

[0295] 41. The catalyst according to paragraph 40, wherein the catalyst is a photocatalyst or an oxidation catalyst.

[0296] 42. Use of a porous nanostructure as a catalyst, as described in any one of paragraphs 28-39. [Examples]

[0297] The present disclosure will be further illustrated by the following embodiments. It should be understood that the following description is intended solely to illustrate specific embodiments and is not intended to limit the above description.

[0298] Materials and methods Transmission electron microscopy (TEM) The dried powder of the specimen was suspended in water and dropped onto a Cu-supported carbon grid, then air-dried at room temperature. The prepared samples were used for TEM, scanning transmission electron microscopy (STEM), high-angle annular dark-field (HAADF), energy-dispersive spectroscopy (EDS), and electron energy loss spectroscopy (EELS) analysis. High-resolution transmission TEM (HRTEM) images and EDS analysis of the nanostructures were performed using a Philips CM 200 microscope (Eindhoven, the Netherlands), while HAADF images and EELS analysis were performed using a JEOL JEM-ARM200F microscope (Tokyo, Japan). Both instruments were operated at an accelerating voltage of 200 kV. In addition, the beam flux was reduced to a very low value of approximately 15 pA to minimize beam damage. Finally, spectroscopy was performed using spectral imaging mode with sub-pixel scanning enabled. This procedure ensured that the beam was always moving during acquisition, minimizing local unevenness. Furthermore, to avoid beam damage to the sample during EELS measurement, the sample was cooled to liquid nitrogen temperature.

[0299] Scanning electron microscopy (SEM) Scanning electron microscope images were obtained by SEM (FEI Nova NanoSEM, secondary electron emission, accelerating voltage 5kV, Hillsboro, OR, USA).

[0300] X-ray photoelectron spectroscopy (XPS) Surface analysis of the samples was performed using a Thermo Fisher Scientific ESCALAB 250Xi spectrometer (Loughborough, Leicestershire, UK) equipped with a monochromatic Al Kα source (1486.6 eV) hemispherical analyzer. XPS samples were prepared by drop-coating an aqueous suspension of nanostructures onto a substrate and then air-drying at room temperature. The pressure in the analysis chamber was maintained below 8–10 mbar during XPS data acquisition. All binding energies were referenced to a C1s signal corrected to 285 eV, and spectra were approximated using convolution of Lorentz and Gaussian profiles.

[0301] X-ray diffraction method (XRD) Mineralogical data for the nanostructures were obtained using a Philips X'Pert multi-purpose X-ray diffractometer (Almelo, Netherlands) with CuKα radiation at [0.15405 nm], with a 2θ of 20–80°, a step size of 0.02°, and a scan rate of 5.5° 2θ / min. Peaks were analyzed using X'Pert High Score Plus software (Malvern, UK).

[0302] Neutron diffraction (ND) Neutron diffraction patterns for structural analysis were collected using the Wombat high-intensity powder diffractometer located in the Open Pool Australian Light-water (OPAL) reactor at the Australian Nuclear Science and Technology Organisation (ANSTO). Two datasets were collected at 1.63 Å and 2.41 Å, using a CaAlNaF3 standard sample as a reference.

[0303] Raman spectroscopy (Raman) Raman data were collected using a Renishaw inVia confocal Raman microscope (Gloucestershire, UK) equipped with a helium-neon green laser (514 nm) and an 1800 g / mm diffraction grating. All Raman data were recorded at a laser power of 35 mW and a spot size of approximately 1.5 μm. Data analysis was performed using Renishaw WiRE 4.4 software, and the spectra were calibrated to a silicon peak located at approximately 520 cm⁻¹.

[0304] Thermogravimetric analysis (TGA) The decomposition of Ce-CP was evaluated using thermogravimetric analysis (TGA, TA Instruments, Q5000, 20-1000°C, heating rate 10°C / min) in various atmospheres of nitrogen and air.

[0305] Fourier transform infrared spectroscopy (FTIR) The chemical species present in Ce-CP were determined using ATR-FTIR, Spotlight 400 FTIR, and PerkinElmer (Waltham, MA, USA) within the wavelength range of 400–4000 cm⁻¹.

[0306] Ab-initio molecular dynamics (MD) simulation Density functional calculations were performed based on reinforced plane-wave pseudopotentials using the Perdew-Burke-Ernzerhof functional [Comput.Mater.Sci.1996,6,15] implemented in VASP code. For the electron configuration, a fine Monkhorst-Pack k-point grid was used with an spacing of 0.05 Å-1 and an energy cutoff of 520 eV. To find the ground state configuration, the inventors performed quenching ab initio molecular dynamics simulations based on a microcanonical ensemble with a target temperature of 20 K and a step of 0.1 fs over 10 ps. Subsequently, the overall geometric configuration for the equilibrium structure was optimized with energy and force convergence criteria of 10⁻⁶ eV and 10⁻² eV / Å, respectively. The final geometric configuration optimization was performed using van der Waals correction (vdw-DFT) based on the application of Michaelides' method [Phys. Rev. Lett. 2004, 92; Phys. Rev. B 2011, 83, 195131].

[0307] Atomic force microscope (AFM) The thickness of the nanosheets was measured using an atomic force microscope (AFM, Bruker Dimension Icon SPM, PeakForce Tapping mode). ScanAsyst-Air probes (Bruker AFM probes) were mounted on the AFM holder and used for all measurements. Samples were transferred onto glass or silicon substrates by applying a slight vacuum. The pixel resolution was 512 samples / line. A slow scanning speed of 0.195 Hz was used to ensure accuracy. Peak force was minimized and the feedback gain settings were appropriately optimized to avoid sample deformation. The thickness of the thin films was determined using height profiles obtained by line scanning.

[0308] Kelvin probe force microscopy (KPFM) Amplitude-modulated KPFM (AM-KPFM) measurements were performed using a Bruker Dimension ICON SPM equipped with a Nanoscope V controller. A platinum-iridium coated AFM tip (SCM-PIT-V2, Bruker AFM probes) was used to scan the surface. The probe was first mounted in a cantilever holder, aligning the laser to the back of the cantilever. The probe was then adjusted to a resonance frequency slightly corrected to the right-hand side of the resonance curve (typically, for normal tapping mode images, the left side of the resonance curve is adjusted, resulting in a slightly repulsive interaction force with the surface. In contrast, for KPFM measurements, a right-hand correction was found to yield better results for selected specimens). The vibration amplitude was maintained at approximately 30-40 nm depending on the specimen. The amplitude setting and gain were appropriately adjusted for each specimen. The scanning speed was approximately 0.3-0.4 Hz, the scanning size was 10 μm, and the resolution was 512 samples per line. The scanning settings included an amplitude setpoint of 172 mV, a gain of 1.1, and a scanning speed of 0.326 Hz. Furthermore, the operating parameters were as follows: the rise height was fixed at 50 nm to avoid any influence from the surface terrain of the specimen (a lower rise height of 30 nm was sometimes used when scanning smaller areas). The drive2 amplitude of the AC bias applied to the chip during rise passage was set to 500 mV at a phase angle of 170°. The same AFM chip was also measured against freshly cut HOPG samples and / or pre-calibrated TiO2 on silicon reference samples for calibration tests performed before and after the specimen measurements. This calibration was important in determining the work function of the platinum chip, which can vary significantly from chip to chip.

[0309] Photoluminescence (PL) spectroscopy PL (Photon spectroscopy) was performed using a spectrofluorometer (RF-5301PC, Shimadzu, Kyoto, Japan). The sample was used as a self-supporting laminated nanosheet.

[0310] Zeta potential measurement Zeta potentials were also determined using a Zetasizer Nano ZS (Malvern Instruments, 4mW He-Ne laser, 633nm). For this procedure, CeO2-x and heterojunction nanostructures were suspended at a concentration of 20 μg / mL in 3 mL of deionized water using separate 10 mL glass tubes. The suspensions were sonicated for 2 minutes, after which measurements were performed.

[0311] Details of first-principles calculations First-principles calculations based on density functional theory (DFT) [Rev.Mod.Phys.2017,89,035003] were performed to simulate and analyze the differences in band structure between ceria nanosheets and their corresponding bulk systems and 0D / 2D heterostructures. The PBEsol functional implemented in VASP software was used. To better handle localized Ce 4f, Fe 3d, Ni 3d, and Zn 3d electron orbitals, the "Hubbard-U" system with U=3eV was adopted. The ionic core was represented by considering the following electrons as valence using the "projection operator reinforced wave" method: Ce 4f, 5d, 6s, and 4d; Fe 3d and 4s; Ni 3d and 4s; Zn 3d and 4s; and O 2s and 2p. The wavefunction is represented on a plane wave reference truncated at 650eV. For integration within the Brillouin zone, the inventors employ a Monkhorst-Pack k-point lattice with a density equivalent to that of a fluorite-type CeO2 unit cell with a 16×16×16 configuration. Geometric configuration relaxation is performed using a conjugate gradient algorithm that allows for simulation of variations in cell shape and volume. Relaxation is stopped when all intraatomic forces fall below 0.01 eV·Å-1. Using these technical parameters, the inventors obtain zero-temperature energies converged to within 0.5 meV per basic composition. To estimate the precise electron density of the state and band gap, the inventors employ a hybrid HSE06 exchange-calibrated functional and perform single-point calculations for equilibrium geometric configurations determined at the PBEsol+U level.

[0312] Photocatalytic activity test The photocatalytic activity of the nanostructures was evaluated by analyzing the photodegradation of methylene blue (MB, M9140, dye content ≥ 82 wt%, Sigma-Aldrich) in aqueous solution under sunlight irradiation. Using a UV-Vis spectrometer (UV-Vis, PerkinElmer Lambda 35, aperture 20 mm × 10 mm), the gradual decrease in the intensity of the MB absorbance peak at 664 nm in the presence of the nanosheets was recorded. The concentration of the nanosheet sample was 1 × 10⁻⁶. -5 The concentration was set at 0.5 mg / mL in 50 mL of MB solution M. To eliminate the role of adsorption / desorption equilibrium between the dye and the surface of the nanosheet during light irradiation, the suspension was stirred with the nanosheet for 15-20 minutes under dark conditions before irradiation. The suspension was irradiated with 100 mW / cm² under simulated light of 1 sun AM1.5. 2 The samples were irradiated at 20-minute intervals for 0 to 120 minutes using the specified illumination output. After isolating CeO2-x and heterojunction nanostructures by centrifugation (10,000 g, 10 mins), their light absorption was measured in the range of 400 to 800 nm. The decomposition of the MB solution was quantitatively evaluated based on the absorbance determined by the peak intensity at 664 nm using UV-Vis spectrophotometry (UV-Vis, PerkinElmer Lambda 35 UV-Vis spectrophotometer, aperture 20 mm × 10 mm). The high photocatalytic stability of the heterojunction nanostructures was tested using the same samples to repeat the photodecomposition test.

[0313] Carbon monoxide (CO) conversion test The CO oxidation catalyst activity was evaluated using a fixed-bed quartz microreactor (inner diameter = 6.0 mm). 50 mg of catalyst sample was placed on the quartz wool bed in the reactor, and the system was purged with N2 gas for 20 minutes. Subsequently, a reaction gas containing CO (10 sccm) and O2 (25 sccm) in N2 (100 sccm) was introduced at an initial temperature of 30°C without catalyst pretreatment (space velocity 162,000 mL / (gcat.h)). The temperature was gradually increased to 150°C in steps determined by the point on the ignition curve. The composition of the present gas was evaluated using a thermal conductivity detector (TCD) and a Young Lin-6100 gas chromatograph equipped with a Carboxen-1010 PLOT column.

[0314] Example 1: Synthesis of metal-coordinated polymers 1.1 Synthesis of Ce-CP Ce-CP tubes were synthesized by chronopotentiometry electrodeposition using an electrochemical station (Ezstat Pro, Indiana, USA) with a resolution of 300 μV and 3 nA (within ±100 μA) in a non-divided three-electrode configuration. Fluorine-doped tin oxide (FTO, Wuhan Geo Scientific Education Instrument, China, 3.0 cm × 1.5 cm, membrane resistance approximately 16 Ω / sq²) on glass, platinum wire (Basi Inc., Indiana, USA, L=23 cm, D=0.5 mm), and Ag / AgCl (Basi Inc., Indiana, USA) were used as the working electrode, counter electrode, and reference electrode, respectively. The electrolyte was prepared from a mixture of 0.05 M ice trichloroacetic acid (TCA) and 0.05 M Ce(NO3)3.6H2O. The pH of the as-prepared aqueous solution was measured to be approximately 3, but the pH was raised to 6 using a 1M NaOH solution while magnetically stirring at 500 rpm. Before electrodeposition, each substrate was stepwise cleaned by sonication in ethanol and acetone, followed by immersion (1 cm) in 45% nitric acid for 2 minutes and drying with compressed nitrogen. Anodic electrodeposition was performed by applying a high voltage of 1.2 V to Ag / AgCl for 50 minutes at room temperature, which, importantly, is within the oxidation region of water. As a result, electrodeposition was accompanied by oxygen bubble generation at the FTO working electrode and hydrogen bubble generation at the Pt counter electrode. The precipitate was washed with a gentle spray of DI water and dried in air at room temperature. Ce-CP tubes were deposited using chronopotentiometry electrodeposition at an applied voltage of 1.4 V. Figure 49(a) shows a typical schematic diagram of a three-electrode electrochemical cell used for the synthesis of Ce-CP tubes, during vigorous oxygen evolution and deposition of self-supporting hexagonal tubes of Ce-CP on a fluorine-doped tin oxide (FTO) substrate.

[0315] 1.2 Synthesis of Ti-CP Ti-CP was prepared by injecting an ice-cold solution of TiCl4 (27.41 μL, 0.25 mmol) into a mixture of DMF (4 mL) and formic acid (7.5 mL), and then heating at 100°C for 16 hours. Subsequently, the as-synthesized powder was washed with DMF and acetone by centrifugation for 3 cycles (5000 g, 20 min), and the resulting Ti-CP powder was dried under vacuum at 60°C for 24 hours.

[0316] 1.3 Synthesis of Zr-CP In a typical procedure, ZrCl4 (58 mg, 0.25 mmol) was added to a mixture of dimethylformamide (DMF, 4 mL) and formic acid (7.5 mL), and then sonicated at room temperature for 10 minutes. The resulting clear liquid was then transferred to a Teflon-coated stainless steel container and heated at 100°C for 16 hours. After cooling to room temperature, the resulting white powder was washed three times with DMF (5000 g, 20 minutes), followed by solvent exchange with acetone. The final product was dried at 60°C for 24 hours to remove the solvent.

[0317] 1.4 Synthesis of MOF-5 For the preparation of MOF-5, Zn(NO3)2.4H2O (3.14 g, 15.8 mmol) was added to a mixture of dimethylformamide (DMF, 100 mL) and terephthalic acid (0.665 g, 4 mmol), and the mixture was stirred at room temperature for 15 minutes. The resulting clear solution was then transferred to a Teflon-coated stainless steel container and heated at 105°C for 24 hours. After cooling to room temperature, the white precipitate was dispersed in chloroform (100 mL) and stirred for 24 hours for solvent exchange. It was then dried under vacuum at 105°C for 24 hours.

[0318] Example 2: Synthesis of nanostructures 2.1 CeO 2-x Nanosheet synthesis Ce-CP powder (50 mg) was added to 50 mL of DI water (pH approximately 7), then stirred for 5 minutes (100 rpm), and subsequently sonicated at room temperature for 10 minutes. After that, 10 mL of NaOH solution (3 M) was added dropwise to convert Ce-CP to CeO2-x This resulted in a conversion to . The obtained nanosheets were collected and washed with DI water. The final product was then air-dried at 100°C for 24 hours. Figure 49(b) shows the exfoliation from the Ce-CP tube to the Ce-CP nanosheet and the subsequent conversion of the Ce-CP nanosheet to porous CeO 2-x CeO3 is produced by a three-step process including oxidation of nanosheets. 2-x A schematic diagram of the formation process is shown.

[0319] 2.2 Large-scale CeO 2-x Nanosheet synthesis 700 mg of Ce-CP was added to 200 mL of DI water at room temperature, and then stirred for 72 hours using a magnetic stirrer (100 rpm). Large sheets with a thickness of 0.5 cm or less were produced using this method. These large-scale sheets were basically formed by laminating thin, atomic-scale nanosheets formed in DI water. Longer stirring times generally resulted in the synthesis of wider and thicker sheets. The addition of NaOH (3M) converted Ce-CP to CeO 2-x It was converted to CeO. Next, the dispersed phase was filtered using filter paper. 2-x The sheet was separated from the liquid. The resulting sheet was dried in a furnace at 100°C for 12 hours. This method allowed CeO 2-x Nanosheets were manufactured on a large scale.

[0320] 2.3 Synthesis of TiO2 Nanosheets TiO2 nanosheets were prepared by adding 10 mg of Ti-CP powder to 5 mL of DI water and then stirring at room temperature for 3 hours (500 rpm). Next, 5 mL of NaOH (0.1 M) solution was added to the mixture and stirring was continued at room temperature for 2 hours. The resulting muddy mixture was washed three times with DI water (10,000 g, 20 minutes), and the resulting nanosheets were dried at 60°C for 24 hours.

[0321] 2.4 Synthesis of ZrO2 Nanosheets ZrO2 nanosheets were prepared by adding 10 mg of Zr-CP powder to 5 mL of DI water and then stirring at room temperature for 3 hours (500 rpm). Next, 5 mL of NaOH (0.1 M) solution was added to the mixture and stirring was continued at room temperature for 2 hours. The resulting muddy mixture was washed three times with DI water (10,000 g, 20 minutes), and the resulting nanosheets were dried at 60°C for 24 hours.

[0322] 2.5 Fe2O3 / Fe3O4-CeO 2-x Synthesis of (FCO) By adding 24 mg of Ce-CP powder to 15 mL of DI water, and then raising the pH to 8 and stirring at room temperature for 30 minutes (100 rpm), CeO 2-x Nanosheets were first prepared. Next, 5 mL of iron(II) chloride (FeCl2) solution (0.3 mM) was added to the acidic Ce-CP nanosheet solution (pH=6), and then 2 mL of NaOH (1 M) was added while gently stirring, and this stirring was continued for 30 minutes. The resulting muddy mixture was washed with DI water (10000 g, 40 minutes) and heated at 200°C for 24 hours.

[0323] 2.6 NiO-CeO 2-x Synthesis of (NCO) By adding 24 mg of Ce-CP powder to 15 mL of DI water, and then raising the pH to 8 and stirring at room temperature for 15 minutes (100 rpm), CeO 2-x Nanosheets were first prepared. Next, 5 mL of nickel(III) nitrate (Ni(NO3)2·6H2O) aqueous solution (0.3 mM) was added to the acidic Ce-CP nanosheet solution (pH=6). Then, 2 mL of NaOH (1 M) was added while gently stirring, and this stirring was continued for 30 minutes. The resulting muddy mixture was washed with DI water (10000 g, 40 minutes) and heated at 200°C for 24 hours.

[0324] 2.7 ZnO-CeO 2-x Synthesis of (ZCO) By adding 24 mg of Ce-CP powder to 15 mL of DI water, and then raising the pH to 8 and stirring at room temperature for 15 minutes (100 rpm), CeO 2-x Nanosheets were first prepared. Next, 5 mL of zinc(II) nitrate (Zn(NO3)2·6H2O) aqueous solution (0.3 mM) was added to the acidic Ce-CP nanosheet solution (pH=6), and then 2 mL of NaOH (1 M) was added while gently stirring, and this stirring was continued for 30 minutes. The resulting muddy mixture was washed with DI water (10,000 g, 40 minutes) and heated at 200°C for 24 hours.

[0325] 2.8 Various CeO from Ce-CP 2-x Synthesis of nanostructures Tubular nanostructures. Ce-CP powder (400 mg) was gently placed in an aqueous NaOH solution (200 mL, 3 M) at room temperature for 30 minutes. The tubes were then washed with water (DI) by three 5000 g centrifugations (10 minutes each). The recovered tubes were then air-dried at 80°C for 24 hours.

[0326] Cubic nanostructures. Ce-CP powder (100 mg) was added to 100 mL of NaOH solution (10 M) and mixed at room temperature using a magnetic stirrer (300 rpm, 5 min). Next, the resulting solution was hydrothermally treated at 140 °C for 24 hours. The resulting cubes were washed three times by centrifugation at 7000 g (10 min). The final precipitate was then air-dried at 80 °C for 24 hours.

[0327] Dumbbell-shaped nanostructures. Ce-CP powder (100 mg) was added to 100 ml of acidic pH 5 DI water at room temperature with gentle stirring (100 rpm). The solution was then burned at 350°C (low speed 1°C / min) for 2 hours. The resulting powder was washed by 3 cycles of centrifugation (5000 g, 10 min). The final product was then air-dried at 80°C for 24 hours.

[0328] Rhombohedral nanostructure. Ce-CP (10 mg) was dissolved in acetone (4 mL) by stirring (300 rpm) at room temperature for 10 minutes. The resulting solution was then recrystallized as rhombohedral Ce-CP at room temperature. The resulting nanoparticles were then collected and allowed to stand quietly in NaOH solution (3 M) for 30 minutes to form CeO2. 2-x The material was converted into a nanostructure. The final product was then washed three times with DI water (3000g, 10 minutes each) and air-dried at 80°C for 24 hours.

[0329] Flower-shaped nanostructure. Ce-CP (40 mg) was dissolved in acetone (2 mL) by stirring (300 rpm) at room temperature for 10 minutes. The resulting solution was then spread on a glass substrate and recrystallized at room temperature to form flower-shaped Ce-CP. Subsequently, the resulting Ce-CP nanostructure was allowed to stand quietly in a NaOH solution (3 M) for 30 minutes to form CeO2. 2-x It was converted to [the desired state]. Finally, the obtained nanoflower was washed three times with DI water (5000g, 15 minutes) and air-dried at 80°C for 24 hours.

[0330] Hollow spherical nanostructures. Ce-CP (40 mg) was dissolved in 4 mL of ethanol under stirring (100 rpm) for 10 minutes at room temperature. The resulting solution was then recrystallized at a low temperature of 0°C for 24 hours to form hollow spherical bodies of Ce-CP. The resulting nanostructures were then left to stand quietly in a concentrated NaOH solution (3 M) for 30 minutes to obtain the resulting CeO 2-x The hollow spherical bodies were washed with water recovered by three cycles of centrifugation (5000g, 10 minutes). The recovered hollow spherical bodies were then air-dried at 80°C for 24 hours.

[0331] Hollow octahedral nanostructures. Ce-CP (40 mg) was dissolved in ethanol (4 mL) by magnetic stirring (100 rpm) at room temperature for 10 minutes. The solution was then recrystallized at room temperature to form hollow octahedral morphology of Ce-CP. Subsequently, the obtained Ce-CP nanostructures were left in an aqueous solution of NaOH (3 M) for 30 minutes to form CeO 2-x Converted to the final CeO. 2-xThe powder was washed by three cycles of centrifugal separation (5000g, 15 minutes), and then air-dried at 80°C for 24 hours.

[0332] Solid spherical nanostructures. Ce-CP (40 mg) was dissolved in 40 mL of ethanol under continuous stirring (100 rpm) at room temperature for 10 minutes. The solution was then transferred to a Teflon-coated steel autoclave reactor for a hydrothermal process (140 °C, 24 hours). The resulting spheres were subjected to centrifugation and redispersion in water three times (7000 g, 10 minutes), and the final precipitate was air-dried at 80 °C for 24 hours.

[0333] 2D-3D scaffold nanostructures. Ce-CP (300 mg) was added to 4 mL of triethanolamine (TEA) and mixed at room temperature using a magnetic stirrer (100 rpm, 10 min). The mixture was then heated to 450 °C at a heating rate of 6 °C / min and a residence time of 3 hours. The resulting powder was then cooled and collected for further characterization.

[0334] Solid octahedral nanostructures. Ce-CP (400 mg) was added to 10 mL of dimethyl sulfoxide (DMSO) at room temperature under gentle stirring for 10 minutes. The solution was then slowly recrystallized at room temperature to obtain the octahedral form of Ce-CP. The obtained Ce-CP nanostructures were then immersed in an aqueous solution of NaOH (3 M) for 30 minutes to obtain CeO 2-x It was converted to [the specified form]. The final dispersion was then washed with DI water by 3 cycles of centrifugation (5000g, 10 minutes), and then air-dried at 80°C for 24 hours.

[0335] Honeycomb scaffold nanostructure. Ce-CP (40 mg) was added to 100 mL of dimethyl sulfoxide (DMSO) under gentle stirring continued for 10 minutes at room temperature. The solution was kept at a low temperature of 0°C for 2 hours to form a honeycomb scaffold at the gas-liquid interface. The resulting scaffold was then recovered by contact printing on a clean glass substrate. The resulting honeycomb scaffold was then heated to 350°C and maintained for 2 hours to form a honeycomb scaffold. 2-x It was converted into a nanostructure.

[0336] CeO derived from Ce-CP by decomposition / reassembly in polar solvents 2-x General procedure for the synthesis of nanostructures 3D CeO 2-x To synthesize the morphology, Ce-CP precursors at various concentrations in the range of 4–120 M (the concentration, temperature, and all details of the obtained morphology are shown in Table A below) were added to pure ethyl alcohol (96.0–97.2%) as a solvent, and then stirred at room temperature for 5 minutes. 4+ The resulting solution, which was yellow in color due to the ions, was evaporated and concentrated at various rates by controlling the temperature in the range of 0°C to +25°C, resulting in the recrystallization of Ce-CP in various forms. Temperatures below 25°C (room temperature) were achieved by using a freezer with a temperature probe inserted.

[0337] From Ce-CP to CeO 2-x The conversion to is carried out by immersing the Ce-CP form in a 6M aqueous NaOH solution and oxidizing it for 30 minutes, followed by washing with a spray of DI water and completing the drying by heating in a furnace at 200°C.

[0338] 2D CeO 2-x The synthesis of the morphological components was carried out using the same method, with the following exceptions. The evaporation and concentration temperature was set in the range of -10 to 0°C, and the corresponding vapor pressures are shown in Table A. To measure the thickness as a function of drying time, Ce-CP nanosheets were deposited on a glass substrate using contact printing technology. Nanosheets of various thicknesses were obtained by controlling the evaporation and concentration time from 6 to 72 hours, and the obtained data are shown in Figure 54. Furthermore, nanosheets were obtained by changing the Ce-CP concentration while keeping the temperature constant at -10°C, and the AFM results are shown in Figure 55. [Table 1]

[0339] 2.9 Synthesis of various ZnO nanostructures from MOF-5 Spherical nanostructures. As-synthesized MOF-5 (100 mg) was dispersed in a vial containing tetrapropylammonium hydroxide (TPAOH, 2 mL, 40 wt%) and stirred at room temperature for 5 minutes. The dispersion was then cooled to 0°C and maintained gently for 72 hours. After nanocrystal growth, the precipitate was washed three times with EtOH (40 mL) and air-dried at room temperature.

[0340] Needle-shaped nanostructures. MOF-5 (100 mg) was dispersed in tetrapropylammonium hydroxide (TPAOH, 2 mL, 40 wt%) and transferred to a Teflon-coated autoclave for a hydrothermal process (140 °C, 24 hours). The resulting precipitate was washed three times with EtOH (40 mL) and air-dried at room temperature.

[0341] Rod-shaped structure. MOF-5 (100 mg) was added to a vial containing H2O (40 mL) and stirred at 40°C for 12 hours (500 rpm). The dispersion was then washed three times with EtOH (40 mL) and air-dried at room temperature.

[0342] Bundle-like nanostructures. MOF-5 (100 mg) was added to a vial containing acetone (39 mL) and KOH solution (1 mL, 10 M), and gently stirred at 40°C for 12 hours. The resulting precipitate was washed with EtOH (40 mL) by centrifugation for 3 cycles (4000 g, 20 min), and the final product was air-dried at room temperature.

[0343] Wafer-shaped nanostructures. MOF-5 (0.1 g) was dispersed in a vial containing tetrabutylammonium hydroxide (TBAOH, 2 mL, 40 wt%), stirred at room temperature for 5 minutes, and maintained under static conditions for 12 hours. The resulting precipitate was then washed with EtOH (40 mL) by centrifugation for 3 cycles (4500 g, 15 minutes), and then air-dried at room temperature.

[0344] Fiber nanostructures. MOF-5 (0.1 g) was added to a vial containing ethanol (39 mL) and H2O (1 mL) and stirred at 40°C for 12 hours. The resulting dispersion was then centrifuged and redispersed three times in EtOH (40 mL), and subsequently air-dried at room temperature.

[0345] Example 3: Synthesis and Characterization of Ce-CP Ce-CP electrodeposition was performed using a modified anodic electrochemical deposition method (chronoamperometry technique; referred to as MACE), in which the current changes as a function of deposition time while a constant potential is applied. Figure 1a shows a scanning electron microscope (SEM) image of a self-supporting Ce-CP hexagonal tube with a bulk layered structure. In addition, transmission electron microscope (TEM) images and corresponding schematic diagrams are shown in Figures 1b and 1c, respectively.

[0346] Layered Ce-CP tubes can be readily delaminated by sonication in deionized water (DI) at room temperature. Figures 1d and 1e show in-situ SEM and TEM images of partially delaminated Ce-CP after 4 minutes of sonication. Corresponding schematic diagrams are shown in Figure 1f. Longer sonication (8 minutes) resulted in complete Ce-CP delamination, as shown in the SEM and TEM images in Figures 1g and 1h, respectively. The progression of total delamination as a function of sonication time is schematically shown in Figures 1c-i. The final step involves raising the pH of the solution to pH=8 during sonication, resulting in incomplete CeO₂ delamination from the Ce-CP nanosheets. 2-x This results in the formation of nanosheets. It is important to note that, as shown in Figures 1j and 1k, high-density nanopores are formed throughout the ultrathin sheet during this transformation. This is because the electric field strength of Ce(IV) is high over a wide pH range, and therefore correspondingly CeO 2-x This is thought to be due to the strong affinity for formation, which allows the organic bidentate trichloroacetate (TCA) linker to be rapidly removed. Figure 1 shows CeO 2-x A schematic diagram of the porous structure of the nanosheet is also shown, and Figure 49 shows a schematic diagram of the modified anodic electrochemical deposition technique, as well as the subsequent exfoliation and organic linker removal.

[0347] Since there is no reference data consistent with the obtained X-ray diffraction (XRD) pattern for Ce-CP, the corresponding crystal structure was investigated by comparative ab-initio molecular dynamics simulation, as well as by XRD and neutron diffraction patterns, as shown in Figures 8-19 and Tables 1-2. The data representing the crystallography of Ce-CP, which was determined to be Ce(TCA)2(OH)2·2H2O, is the triclinic space group.

number

[0348] The crystalline structure of the layered Ce-CP is shown in Figure 1m, where interlayer-inserted protons and chloride ions of the terminal TCA ligand mutually maintain the interlayer space. The application of ultrasound to the Ce-CP tube enhances delamination by cutting the nanosheet vibrations and the resulting facilitated water molecule permeation (Figure 1n). Furthermore, the c-axis lattice parameter of the Ce-CP crystalline structure was measured to be 1.1n, which represents the thinnest possible Ce-CP monolayer Ce-CP nanosheet. Increasing the pH of the solution leads to the dissolution of TCA from two surfaces of the M-OH substructure (Figure 1n). This is followed by the highly reactive internal M-OH(Ce(OH)2) 2+ A conversion occurs from the substructure to the more stable Ce(OH)4, followed by the stable CeO 2-x (Figure 1o) is rapidly formed without any morphological changes. Ce-CP to CeO 2-x The structural evolution during the transformation is studied using XRD and SAED analysis (Figure 20). To confirm the removal of TCA, Ce-CP and CeO 2-x Energy-dispersive spectroscopy (EDS) elemental mapping was performed on both nanosheets, as shown in Figures 21 and 22, respectively. Furthermore, Ce-CP to CeO 2-x The rapid evolution to this state is studied by in-system laser Raman microspectroscopy of nanosheets subjected to alternative removal methods (Figure 23).

[0349] Figure 6 shows a graph of current-deposition time, where the current density increases rapidly in the initial stages of deposition. The high current density is thought to be due to the oxygen evolution reaction at the working electrode (FTO substrate). However, the current density decreases after approximately 100 seconds of potential application, followed by a gradual decrease after approximately 160 seconds. The fluctuation in current density was studied as a function of deposition time using SEM images based on the nucleation / growth mechanism (inset in Figure 6). The image obtained at the peak current density (Figure 6b) revealed small Ce-CP nuclei. The lower conductivity of the Ce-CP polymer compared to the FTO substrate may contribute to the decrease in current density. Continued growth of the Ce-CP polymer led to a reduction in the exposed FTO surface, and therefore to a decrease in current density. Interestingly, Figure 10c shows that after 150 seconds of deposition, the nuclei grow perpendicular to the substrate, forming hexagonal rods. By increasing the deposition time (Figure 6d), holes are formed in the center of the hexagonal rods, and eventually the hexagonal rods transform into hexagonal tubes (Figure 6f). This transformation can be attributed to the application of a high current density, which caused the generated oxygen bubbles to move perpendicular to the substrate. Therefore, the morphological evolution proceeds in a way that minimizes the contact surface between the Ce-CP and the FTO substrate, because this enhances the reachability of water in the FTO substrate, leading to the oxygen evolution reaction.

[0350] Applying a high current density in the oxygen-evolving region resulted in a high rate of oxygen bubble generation in the region adjacent to the FTO substrate. The high O2 concentration environment leads to oxidation from Ce(III) to Ce(IV), which is shown as step (1) in Figure 7. From another perspective, the water splitting reaction generates 1 mole of oxygen, followed by the formation of 4 moles of protons, which leads to a rapid decrease in local pH and the formation of a strongly acidic atmosphere. All of these reactions occur above the water stability range indicated in blue in Figure 7.

[0351] The stability region of the Ce(IV) species in aqueous solution exists because of the high electric field strength (affinity for hybridization) of the Ce(IV) species. Therefore, oxidation from the Ce(III) species to Ce(IV) leads to the formation of Ce(IV) hydroxide, even under acidic pH conditions, although it has an unsaturated coordination bond. This is also shown in the Pourbet diagram (Figure 7), where rapid proton generation occurs following the formation of Ce(IV) hydroxide with a low coordination number (step (2)). In the final step, the presence of the TCA molecule along with the unstable Ce(IV) species leads to a coordination bond between the Ce(IV) hydroxide and the TCA ligand, forming a monolayer structure. The presence of high concentrations of protons due to the acidic pH allows the protons to interlayer-insert into the interlayer space of the coordination monolayer structure of Ce(IV) and TCA, establishing van der Waals interactions between the layers and leading to the formation of (Ce(OH)2(TCA)2.2H2O).

[0352] The possible chemical reactions leading to the formation of Ce-CP are as follows: (1) Deprotonation of TCA in water and the subsequent decrease in pH from 6.5 to less than 2.3: CCl3COOH + H2O → H3O + +CCl3COO - (Formula 1) (2) Free Ce obtained by the dissociation of cerium nitrate salt in solution 3+ and release of nitrate ions: Ce(NO3)3.6H2O→Ce 3+ +3NO3 - +6H2O (formula 2) (3) At pH=6, the oxidation voltage of cerium was found to be 0.55V relative to Ag / AgCl, while the oxidation of water began at 0.8V. Applying a constant potential of 1.2V relative to Ag / AgCl resulted in rapid oxygen evolution at the anode (FTO) surface (Equations 3-5): 2H2O → 4H + +O2+4e - (Formula 3) 4OH - →4H + +2O2+4e - (Formula 4) HO2 - +OH - →H2O+O2+2e - (Formula 5) The high oxygen molecule generation rate on the FTO substrate leads to the oxidation of Ce(III) species to Ce(IV). However, during the oxidation of water, 1 mole of oxygen is generated followed by the formation of 4 moles of protons, which in turn leads to a rapid decrease in local pH and an increase in proton concentration. Under these conditions, the Ce(IV) hydroxide species is in a soluble form. In addition, due to the low pKa value of TCA, deprotonated TCA acts as a second building block (SBU), bridging the Ce(IV) hydroxide species and leading to the formation of a novel polycrystalline Ce-CP. The corresponding equation is shown below: Ce 4+ +2OH - +2TCA+2H2O=Ce(OH)2(TCA)2.2H2O (Formula 6)

[0353] Layered Ce-CP tubes can be readily delaminated by sonication in deionized water (DI) at room temperature. Figures 1d and 1e show in-situ SEM and TEM images of partially delaminated Ce-CP after 4 minutes of sonication. The corresponding schematic diagram is shown in Figure 1f. Longer sonication (8 minutes) resulted in complete Ce-CP delamination, as shown in the SEM and TEM images in Figures 1g and 1h, respectively. The progression of total delamination as a function of sonication time is schematically shown in Figures 1c-i. The final step involves raising the pH of the solution to pH=8 during sonication, resulting in incomplete CeO₂ delamination from the Ce-CP nanosheets. 2-x This results in the formation of nanosheets. It is important to note that, as shown in Figures 1j and 1k, high-density nanopores are formed throughout the ultrathin sheet during this transformation. This is because the electric field strength of Ce(IV) is high over a wide pH range, and therefore correspondingly CeO 2-x This is thought to be due to the strong affinity for formation, which allows the organic bidentate trichloroacetate (TCA) linker to be rapidly removed. Figure 1 shows CeO 2-x A schematic diagram of the porous structure of the nanosheet is also shown.

[0354] The Raman spectra of Ce-CP (Figures 11 and 11A) were comprehensively analyzed and assigned to pure TCA and vibrational modes of CeO2. The data show that some of the peaks observed in the Ce-CP spectrum are also present in the TCA spectrum, suggesting the presence of TCA molecules within Ce-CP. (288 and 430 cm⁻¹) -1 The peaks centered at 688 cm are thought to be due to asymmetric and symmetric bending vibrations of the C-Cl bond, respectively. -1 The peaks belong to the symmetric stretching vibration mode of the C-Cl bond, while the peaks at 845 and 744 cm² are associated with the symmetric stretching vibration mode. -1 The peak is due to the asymmetric stretching vibration mode of the same coupling. 952cm -1 The peak located at (952–962 cm⁻¹) corresponds to the symmetric vibrational modes of the carbon-carbon bond (CC). Further comparison of the two spectra reveals that some of the peaks (952–962 cm⁻¹) correspond to the symmetric vibrational modes of the carbon-carbon bond (CC). -1 700-740cm -1 , and 683~688cm -1 A Raman shift was observed in ), which is thought to be due to a change in the vibrational mode of the bond in the TCA structure due to interaction with the cerium ion. In addition, TCA has a vibrational mode of 1746 cm², which corresponds to the vibrational mode of the free carboxylic acid group (COO). -1 There are peaks at 1367 (symmetric stretching vibration) and 1662 cm⁻¹ in the Ce-CP spectrum. -1 The (asymmetric stretching vibration) is split into two peaks. The split occurs at 455 cm. -1 The peak observed at 214cm is likely due to the interaction between the COO group and Ce, which leads to the formation of the Ce-O bond. -1 and 360cm -1 The peaks correlate with the in-phase and out-of-phase vibrational modes of the Ce-CP structure. The Ce-CP spectrum includes peaks at 455 and 470 cm⁻¹. -1 There are two main peaks located at [location]. The former is attributed to the symmetric stretching vibrations of cerium and its coordinating oxygen, while the latter originates from the vibrational modes of cerium bonded to chlorine and oxygen.

[0355] The FTIR spectra of the Ce-CP tube (Figure 12) show values ​​at 3620 and 3410 cm⁻¹. -1 The frequency band centered at 1660 cm² exhibits stretching vibrations of the hydroxyl group, revealing the presence of water and OH groups in Ce-CP. -1 and 1360cm -1 The peak is thought to be due to the asymmetric and symmetric stretching modes of the carboxyl group bonded to the cerium cation. Also, 1040 cm -1 and 966cm -1 The peaks are due to the bending vibrations of the carboxyl group and the symmetric vibrational modes of the carbon-carbon bond (CC), respectively. Similar to the Raman spectrum, at 688 cm⁻¹ -1 744cm -1 and 845cm -1 The peak is thought to be due to the C-Cl oscillation mode.

[0356] XPS data from Ce-CP tubes (Figure 13) showed that peaks corresponding to the 3d, 1s, 1s, and 2p orbitals of cerium, oxygen, carbon, and chlorine elements can be detected at binding energies in the ranges of 880–920, 529–535, 284–292, and 198–202 eV, respectively. In cerium, the spin-orbital coupling of the d orbital (3d 5 / 2 and 3D 3 / 2 Ce represents ) 3+ and Ce 4+ Two oxidation states exist. 3d 5 / 2 Ce in placement 4+ and Ce 3+ The corresponding bond energies are located at 883, 889, and 899 eV, and 881 and 886 eV, respectively (Table 1). The peak located at 530 eV is Ce 4+ This corresponds to the hydroxyl bonded to the TCA. The organic oxygen peak in TCA may be observed at 532 eV. At a bond energy of 534 eV, there is a small, broad peak representing the H2O structure. All peak positions are shown in Table 1. [Table 2]

[0357] Quantitative analysis of elements in the Ce-CP structure was performed by peak inverse convolution using the Gaussian approximation, and the results are shown in Table 2. From the analysis, the stoichiometry of Ce-CP is based on atomic percentages: Ce(OH) 1.8 (TCA) 2.0 (H2O) 1.0 It is identified as such. Furthermore, the XPS results were used for TGA analysis to confirm the molar ratio of Ce-CP structures from wt%, which will be described in detail in the following section.

[0358] Quantitative analysis of elements in the Ce-CP structure was performed by peak inverse convolution using the Gaussian approximation, and the results are shown in Table 2. From the analysis, the stoichiometry of Ce-CP is based on atomic percentages: Ce(OH) 1.8 (TCA) 2.0 (H2O) 1.0 It is identified as such. Furthermore, the XPS results were used for TGA analysis to confirm the molar ratio of Ce-CP structures from wt%, which will be described in detail in the following section. [Table 3]

[0359] TGA analysis of Ce-CP (Figure 14) showed similar patterns under both nitrogen and air atmospheres. Four stages were present, during which adsorbed water, structured water, carbon chloride, and CO2 were removed from Ce-CP, respectively. The results indicate that 35.8 wt% of the total Ce-CP was converted to CeO2 under both conditions. The weight percentages of each organic component and the resulting product are shown in Table 3, along with relevant XPS analysis data for comparison. XRD and Raman spectroscopy of the Ce-CP samples after the TGA test (data not shown here) revealed that a cubic fluorite-type structure of CeO2 was formed regardless of the gas used for heat treatment. [Table 4]

[0360] Characterization data of the Ce-CP crystal structure To identify Ce-CP structures that do not match existing structures in the crystallography database (Cambridge Crystallography Data Centre (CCDC)), we attempted to fabricate Ce-CP single crystals using vapor bed diffusion. However, all attempts resulted in the formation of polycrystalline Ce-CP. Therefore, based on the chemical composition of the obtained (Ce(OH)2(TCA)2·2H2O) and the obtained X-ray (1) and neutron (2) diffraction patterns, we performed Rietveld analysis (using the FullProf program package) by combining all three datasets to enhance the level of information. We refined the lattice parameters, atomic positions, and zero-shift parameters. Good approximations were obtained for both the X-ray and neutron diffraction patterns of Ce-CP (Figures 15 and 16). However, while the positions of the Ce atoms and lattice parameters were found to be very similar to those in the experimental data, the physical interpretation of the obtained structure was challenging due to the uncertainty of the positions of lighter elements, particularly H (Figure 17).

[0361] To obtain a physically meaningful structure, the lattice refined by the Rietveld method was used as a guideline for density functional theory and subsequent ab initio molecular dynamics calculations (particularly lattice parameters and Ce positions). To approximate the coordination environment around the cerium atoms in the Ce-CP structure, a small stoichiometric supercell composed of Ce(OH)2(TCA)2.2H2O, having one-sixth the volume of the refined experimental structure, was first used (Figure 17). Many coordination possibilities, such as Ce coordinated with Cl and O atoms of TCA, were comprehensively compared. The most stable coordination relaxation structure is shown in Figures 18A and 18B. It was found that seven O atoms coordinated to Ce, of which two came from the OH group, two from each water molecule, and three from the two TCA molecules. Subsequently, experimentally refined

number

[0362] The final optimized structure shown in Figure 18B(a) reproduces the major diffraction peaks at low angles centered around 7.34982° and 813390° with reasonable accuracy. It should be noted that the low resolution of the XRD measurement limits the use of experimental diffraction patterns for evaluating the DFT optimized structure. Consequently, comparison with the measured pattern can only estimate the positions of larger atoms, while it is almost impossible to evaluate finer details, such as the H bond network and the positions of hydrogen atoms, based on this comparison.

[0363] Furthermore, Ce-O (TCA) The bond is approximately 2.60 Å long, Ce-O (H2O) Bonding and 1.96 Å Ce-O (OH) It was found to be approximately 2.56 Å, longer than either bond. (TCA) The bond reinforces the view that this bond is fragile. The empty Ce 4f, 5d, and 6s states in Figure 18B(b) indicate the oxidized states of the 4+ Ce ion. Furthermore, the lack of overlap between the Ce states and the coordinating O states (Figures 18B(b)-(e)) suggests the absence of a strong covalent bond to Ce.

[0364] In summary, based on the results described herein, the XRD pattern of Ce-CP powder is triclinic Ce(OH)2(C2O2Cl3)2·2H2O, space group

number

[0365] Photoluminescence spectrum of Ce-CP CeO at room temperature 2-x Figure 46 shows the photoluminescence (PL) emission of the heterojunction structure. 2-x The PL spectrum of the nanosheet shows two small, broad emission lines with wavelengths of 426 nm (blue emission) and 510 nm (green emission). The former is F ++→This is thought to be due to a 4f1 transition, because F ++ The state is just below the 4f0 band, which acts as an electron trap, and the 4f1 state acts as a hole trap. On the other hand, the latter is Ce as a hole trap state. 3+ This is caused by the presence of oxygen valence as an electron trap state. Radiative recombination of these two traps leads to excitation at a wavelength of 510 nm. CeO 2-x The weaker PL intensities of these two emission types in the nanosheet compared to the reported CeO2 nanostructures further supports the idea that the diffusion pathways for charge carriers are shorter and therefore radiative recombination is reduced.

[0366] Example 4: Synthesis and Characterization of Ti-CP and Zr-CP The flexibility of the manufacturing method disclosed herein is demonstrated by the synthesis of layered titanium-based CP (Ti-CP) and zirconium-based CP (Zr-CP). Details of the morphological and structural characterization of these bulk layered MCPs are shown in Figures 24-29. Similar to Ce-CP, Ti-CP and Zr-CP were rapidly exfoliated as nanosheets in a basic aqueous solution, as shown by TEM and EDS analysis (Figures 30-39). 2-x , TiO 2-x and ZrO 2-x Morphological analyses of the nanosheets are shown in Figures 3a-c, respectively, and the TEM images reveal the porous nanostructures of metal oxides derived from MCP. Figures 3d-f show the SAED patterns of disorderly oriented polycrystalline nanosheets attributed to CeO2, TiO2, and ZrO2, respectively. Considering the ultrathin nature of the porous nanosheets, surface chemical analysis provides a de facto bulk analysis, given the XPS transmission depth of approximately 3 nm. For example, the deconvolution of the Ce 3d orbital in the XPS spectrum reveals the CeO2 2-x Quantitative analysis (Figure 40) was performed to determine high Ce 3+ The concentration was revealed, but this is generally the corresponding oxygen vacancy concentration due to charge compensation ([V O ** These results are related to the EELS data shown in Figures 2d and 2e.

[0367] To measure the thickness of porous metal oxide nanosheets, atomic force microscopy (AFM) imaging was obtained by depositing nanosheets onto a silicon substrate, as shown in Figures 3g-i. The corresponding height profiles are shown in two height levels from the substrate in Figures 3j-l. 2-x In this case, these are approximately 1.1 nm and 1.2 nm, indicating that the nanosheet has a thickness of 2 unit cells (CeO2 unit cell = 0.54 nm). 2-x and ZrO 2-x The thickness of the nanosheets was measured to be approximately 10.0 nm and 1.8 nm, respectively, corresponding to the thickness of 20-40 and 3-4 unit cells. 2-x The relatively thicker nanosheets may be due to loose packing resulting from the anisotropy of tetragonal anatate crystals, while the thinner ZrO 2-x Nanosheets likely originate from a de facto equiaxial lattice. These data suggest that self-assembled metal oxides with equiaxial or possibly highly anisotropic and therefore self-aligned nanostructures are somewhat more likely to produce ultrathin nanosheets.

[0368] Figure 32 shows the Raman spectrum collected from TiO2 nanosheets. According to group theory, Eg (approximately 144 cm⁻¹) -1 ), B1g (approximately 397cm -1 ), B1g / A1g (approximately 516cm -1 ) and Eg (approximately 639 cm -1 There are four main peaks that are thought to be due to TiO2 with a Raman-activated mode. Therefore, the Raman spectrum of the sample shows anatate (tetragonal) TiO2, although a slight shift is observed in the position of the assigned peak. In particular, the peak with the highest intensity is at 153 cm⁻¹. -1 The bands are shifted to blue. Similarly, the B1g and Eg bands are 397 and 639 cm, respectively. -1The peak appeared at a different position than the predicted frequency. The asymmetric broadening of the peak and the observed shift can be explained by phonon confinement phenomena occurring due to reducing the crystal size to the nanoscale. The nanosheets in this study have a porous structure consisting of nano-sized crystallites with a diameter of 2-4 nm (as shown in high-resolution TEM images), which can explain these slight shifts. Furthermore, 690 cm⁻¹ -1 The small, broad peak located there is Rutile TiO 2-x This could be the cause.

[0369] Figure 33 shows the XPS peaks for the carbon 1s orbital in both Ti-CP and TiO2. The peak at 248.8 eV is thought to be due to CC bonding in either the sample composition or contaminants adsorbed on the sample surface. The peak at 286 eV is attributed to COC bonding in formic acid anhydride, which is measured to have a concentration of 9.70 at% by calculation of the corresponding peak area. However, this amount dropped to only 2.20 at% upon conversion to TiO2 nanosheets. Furthermore, the peak at 288.5 eV corresponds to the OC=O bond of formic acid, but its atomic percentage decreases to approximately 1 / 13th, from 10.36 at% in Ti-CP to 0.80 at% in TiO2. The removal of the formic organic linker by TiO2 production is also confirmed by examining the XPS peak for oxygen (Figure 34). The peak at 532.1 eV is due to the 1s orbital of organic oxygen, but this peak disappeared in the oxygen spectrum of TiO2. The two main peaks due to the oxygen 1s orbital are located at 530.0 eV and 531.85 eV, respectively, in the O-Ti 4+ and O-Ti 3+ That is the case.

[0370] The Raman spectra of zirconia nanosheets and their associated approximations (reproduced by a set of eight Lorentz bands corresponding to the most apparent vibrational modes) are shown in Figure 37. The bands appearing at approximately 195 and 450 are the A bands of Zr-Zr and Zr-O in monoclinic zirconium oxide. gThis is thought to be due to vibration modes, while 180 and 240 cm -1 A broad line consisting of two peaks, and 550cm -1 The most prominent peak located at [location] is attributed to the presence of the cubic phase. Therefore, the Raman data indicates the coexistence of monoclinic and cubic phases in zirconia nanosheets.

[0371] The conversion from Zr-Cp to ZrO2 was also investigated by XPS analysis, as shown in Figures 38 and 39. Figure 38 shows the XPS peaks for the carbon 1s orbital of Zr-CP (bottom) and ZrO2 (top). The unavoidable peak at 248.8 eV is thought to be due to CC bonding, which mainly originates from contaminants adsorbed on the surface of the sample. The peaks at 286.0 and 288.5 eV are related to the COC and OC=O bonds of formic acid anhydride bonded to Zr. The total atomic percentage of these two peaks was measured at 23.14 at% for Zr-CP and decreased to 3.87 at% for ZrO2. It should be noted that the peak at 286.0 eV may be due to surface bonding between CO2 in the air and surface oxygen of the sample due to exposure to air, and therefore the presence of CO3 due to surface bonding with CO2 in the air. This bond is confirmed by the XPS results obtained from the oxygen 1s orbital shown in Figure 39. The organic peak at 532.0 eV in Zr-CP is removed from the XPS spectrum for ZrO2. Furthermore, the Zr peak appearing at approximately 530 eV in Zr-CP is also removed. 4+ The small peak of -O dramatically increased in ZrO2. Interestingly, in ZrO2, O-Zr 3+ The peak at 531.6 eV, which is thought to be due to [the following factor], accounts for 27.0 at% of the total oxygen concentration of ZrO2, clearly indicating the formation of incomplete ZrO2. It should be noted, as previously reported, that the peak located at 533.2 eV is related to the oxygen in adsorbed water.

[0372] Example 5: Synthesis of heterostructures Porous CeO 2-xThe applicability of nanosheets can be expanded by using them as a mold material in the fabrication of mixed 0D / 2D heterostructures with Fe-based, Ni-based, and Zn-based transition metal oxides (TMOs) (0D). Porous CeO 2-x The nanosheets were dispersed in an aqueous solution (pH=6), resulting in a relatively stable suspension with a zeta potential of -25mV (Figure 41), slightly lower than the threshold of -30mV for a sufficiently stable colloidal system. In addition, considering the chemical species formation diagram of transition metal (TM) ions (Figure 42), CeO 2-x The dominant species in the acidic pH range of the suspension is TM n+ This is predicted. Therefore, this situation establishes an electrostatic attraction between positively charged metal species and negatively charged porous nanosheets, thereby leading to a mechanism for the aggregation of metal species on the nanosheet surface. This is supported by the decrease in zeta potential of Fe, Ni, and Zn nanostructure suspensions, respectively. This method can significantly improve the functionality of nanosheets by minimizing vdW interactions between planes, preventing layer stacking, and maximizing accessibility to the active site.

[0373] Furthermore, mixed 0D / 2D heterostructures can lead to sufficient hybridization between atomic orbitals, resulting in enhanced carrier delocalization at the junction interface. Elemental, mineralogical, and crystallographic studies of the nanostructures were performed using EDS, laser Raman microspectroscopy, and XRD, as shown in Figure 4.

[0374] EDS mapping of the nanosheets in Figures 4a-c demonstrates the formation of nanostructures, revealing a uniform distribution of 0D TMO. Furthermore, the relationship between TMO and CeO 2-x The coexistence of these substances was confirmed by laser Raman microspectroscopy (Figures 4d-f). The peak for pure CeO2 was 464 cm⁻¹. -1 Because it is located in Fe2O3 / Fe3O4-CeO 2-x (FCO), NiO-CeO 2-x (NCO) and ZnO-CeO 2-x (ZCO) Approximately 460cm -1A large peak is located there (Ce(IV) and the surrounding eight oxygen atoms are due to symmetrical stretching of F 2g (Assigned to the vibration mode) is V O ** This suggests a red shift to lower wavenumbers that is consistent with the expansion strain caused by it. Furthermore, approximately 600 cm -1 The peak located at V O ** This is thought to be due to a defect-induced mode originating from [the specified location]. 230cm in Figure 4d -1 The peaks are attributed to the A1g oscillation mode of α-Fe2O3, while the peaks at 294, 395, and 620 cm⁻¹ are attributed to the A1g oscillation mode of α-Fe2O3. -1 The peak corresponds to the Eg oscillation mode of α-Fe2O3. In addition, there are three inversely convolved peaks, which are thought to be due to the oscillation mode of Fe3O4, at 310(T 2g ), 538(T 2g It is present at ) and 680 (A1g). Figure 4e shows the coexistence of NiO (red-purple peak) and CeO2 (gray peak). Peaks for NiO due to the Eg, 1-phonon transverse wave optical branch (1T), 1-phonon longitudinal wave optical branch (1L), and 2-phonon transverse wave optical branch (2T) vibrational modes are at 287, 380, 560, and 690 cm⁻¹. -1 It is located at 380 cm. The inverse convolution of the ZCO peak in Figure 4f is 380 cm. -1 and 412cm -1 This reveals two peaks, which are A of ZnO. 1T and E 1T It belongs to the vibration mode. Furthermore, 580cm -1 The peak is attributed to the E1L oscillation mode of ZnO. Similarly, TMO and CeO 2-x The coexistence with nanosheets was confirmed by XRD analysis, as shown in Figures 4g-i. Further data analysis of the nanostructure is shown in Figure 43.

[0375] CeO 2-xFigure 46 shows the photoluminescence (PL) emission of a heterojunction structure at room temperature. At FCO, the peak intensity drops to near zero, indicating minimal electron / hole recombination due to rapid charge carrier separation via a very short diffusion pathway. The broad emission band located at approximately 450 nm is caused by surface oxygen vacancies and atomically thin CeO 2-x This confirms the high concentration of oxygen vacancies in porous nanosheets. Adding NiO and ZnO significantly reduced the UV emission peak near the band edge, while simultaneously shifting it towards deep-level (DL) emission within the green wavenumber range. This decrease is attributed to Ni 2+ and Zn 2+ The band electrons of the localized d electrons and CeO 2-x This is thought to be due to sp-d exchange interactions with the nanosheets. Furthermore, the high intensity of PL emission in both NCO and ZCO indicates an increase in defect concentration. The increase in defect concentration can also be confirmed by determining the trapping sites from the XPS valence band results (Figure 44). For NiO, the green emission band at 560 nm indicates defects in the NiO lattice, such as Schottky pair defects, interstitial oxygen traps, and Ni 2+ Ions and Ni 3+ This is thought to be due to nickel vacancies generated by charge transfer between ions. In ZCO, the small, broad emission peak at 390 nm is thought to be due to the recombination of free excitons via exciton-exciton collisions, but this is not very significant in any heterojunction nanostructure. The weak, broad blue emission band at approximately 460 nm is deep-level emission (DLE) caused by oxygen vacancies or interstitial zinc ions in the ZnO nanomaterial. A broad green emission band was observed at 550 nm in all ZnO nanomaterials, which may be due to the presence of defects such as monovalent ionized oxygen vacancies.

[0376] Example 6: Formation of nanostructures with unique morphologies by controllable decomposition / reassembly of metal-coordinated polymers Ce-CP exhibits environmental stability during long-term exposure. In contrast, the instability of Ce-CP in polar solvents leads to its rapid dissociation. Under controlled removal of the solvent, the ultrafine crystallites of CP reassemble to form unique nanostructures. This stems from the weak electrostatic coupling between the cation and the organic linker in unstable CP. High rarity This is a new CeO 2-x This provides a framework for the simple and controllable destruction / reconstruction of CP crystallites for forming nanostructures. These nanostructures are prepared by varying processing parameters, including solvent type, solute concentration, temperature (T), and time (t). Subsequent post-oxidation in air or time course in a NaOH basic solution causes the Ce-CP nanostructures to resemble CeO 2-X It is converted into nanostructures. The feasibility, high yield, and suitability of the method of this disclosure, in which CP acts solely as a precursor, are due to the fact that CeO2 is inherently a non-layering material, despite the functional CeO 2-x This enables the large-scale synthesis of nanostructures, such as ultrathin nanosheets (see Figures 48u~x) and 2D-3D scaffolds (see Figure 79).

[0377] By adjusting the very weak bond between the metal ion center and the coordination linker, various metal oxide (MO) structures can be obtained from a single metal coordination polymer precursor. The success of this method is confirmed by the synthesis of novel unstable cerium-based coordination polymers (Ce-CP) that can be subjected to controllable decomposition / reassembly in a polar solvent (ethanol). This allows for the formation of distinct Ce-CP nanostructures by controlling the kinetics of the reassembly process. Post-treatment of Ce-CP nanostructures by low-temperature thermal decomposition and / or time-course in alkaline solution yields defect-rich 2D and 3D nanostructure forms of CeO 2-x This led to the formation of [a specific structure]. This method provides a rapid, mold-free, precisely controlled, and economical method for synthesizing MCPs of a specific structure.

[0378] Electrochemical Production of Ce-CP CeO 2-xTo synthesize nanostructures, Ce-CP precursors were prepared as described herein. A schematic diagram of the synthesis process (Figure 50(a)) shows the growth of self-supporting Ce-CP hexagonal rods on a fluorine-doped tin oxide (FTO) substrate, as shown by the SEM image in Figure 51. Ce-CP rods were synthesized in an aqueous solution under an anodic electrochemical current within the oxygen-evolving region. One major factor in the precipitation of the Ce-CP precursors was the application of a high current density within the oxidizing range of water, which resulted in vigorous oxygen bubble generation, leading to the formation of an oxidizing atmosphere and an acidic pH both on and around the surface of the working electrode.

[0379] The stability of the Ce-CP structure was analyzed, and judging from the XRD patterns of the corresponding samples (Figure 52), it was found to be fairly stable even after exposure to air for 90 days after precipitation. However, Ce-CP exhibited high instability when exposed to the polar solvent ethanol, as shown in step 1 of Figure 50(b).

[0380] The simplified molecular structure of the hexagonal Ce-CP rod consists of eight coordinated cerium ions (Figure 50(c)), with the coordinating oxygen ions linked to trichloroacetate (TCA) ligands (four), hydroxyl ions (two), and water molecules (two). In addition, the cerium ions are cross-linked by covalent bonding with the carboxyl groups of the TCA ions, thus forming a two-dimensional (2D) substructure. However, weak electrostatic interactions exist in the interlayer space of the 2D Ce-TCA substructure, leading to the formation of a layered structure (Figure 1A).

[0381] The Ce-CP structure readily decomposes upon exposure to ethanol, forming a pale yellow, clear solution (Figure 50(d), (e)). The high instability of Ce-CP and the resulting rapid decomposition are generally attributed to the retention of Ce ions in the 4+ valence state. From a thermodynamic standpoint, Ce 4+ Aeon is Ce 3+ The electric field strength is higher compared to ions. As a result, Ce is as shown in the Pourbet diagram (Figure 7).4+ Even at acidic pH, the surrounding OH - While there is a strong tendency to attract Ce 3+ It tends to remain in a cation state.

[0382] As discussed herein, the aqueous solution conditions used in the production of Ce-CP resulted in strongly acidic conditions with a pH of <2.3, which led to the formation of Ce(OH)2 2+ This was the primary species produced. From the related chemical species formation diagram, it appears that this species is a stable solute at these pH values ​​but becomes unstable at higher values. Furthermore, the Pourbet diagram (Figure 7) shows Ce(OH)2 2+ Since it was shown that it exists only in the water-instability region, its presence requires the application of an external bias and a appropriately low pH. The application of an external bias causes it to fall out of the water-stable range, leading to rapid proton formation and a decrease in local pH. Therefore, under the typical aqueous treatment conditions used in the research of this invention, Ce(OH)2 2+ Positively charged Ce(OH)2 is not formed. 2+ The coexistence of unsaturated coordination bonds within and negatively charged bidentate TCAs as organic linkers leads to the formation of Ce-CPs with a unique layered structure. 4+ The aqueous chemistry of Ce is such that there are coordination polymers that cannot be decomposed / reassembled. 3+ This is distinct from aqueous chemistry.

[0383] In the recrystallization of Ce-CP from ethanol, this local bond configuration, therefore Ce 4+ The presence of Ce-CP is preserved, thereby enabling the reformation of Ce-CP (Figure 50(f), (g)). The design of the final structure can be adjusted by controlling the kinetics of solvent evaporation and the concentration of the Ce-CP solute. This novel technique results in the precise and controllable assembly of nanostructures at room temperature, or even lower temperatures, without the use of mold materials. Therefore, this method can be used to form unique structures that are extremely difficult to form by existing techniques.

[0384] Formation of a Ce-CP monolayer at the ethanol / air interface results in 2D Ce-CP nanosheets and porous CeO obtained therefrom. 2-x Research on fabricating cerium-based porous nanosheets, and more importantly, structures with controllable thickness, is very limited.

[0385] This specification describes how to perform slow kinetics of ethanol evaporation at low temperatures of -10°C and vapor pressures (VP) of 0.744 kPa on porous ultrathin CeO of various thicknesses. 2-x We succeeded in fabricating nanosheets. As shown in the schematic diagram of the Ce-CP monolayer in Figure 53(a), these conditions allowed individual Ce-CP layers to be formed by de facto Langmuir-Bludget deposition.

[0386] In contrast to the study by Wang et al., which used separate solvents and surfactants, the mechanism shown in Figure 53(b) involves a surface assembly of Ce-CP at the ethanol / air interface, where ethanol exhibits dual functionality as both a solvent and a surfactant in this bottom-up 2D process. The juxtaposition of the positively charged hydrophobic -CH3 groups of ethanol in the air leads to the establishment of a negatively charged layer on the surface consisting of the hydrophilic -OH groups of ethanol. The formation of this layer is facilitated by the presence of Ce in solution. 4+ This imparts a polar attraction to the cerium, thus forming the basis for the development of a cerium-rich electrostatic bilayer. 4+ Coordinated and aligned COO - Each group contains a negative hydrophobic tail of a -CCl3 group, and the Ce-CP monolayer terminates at this layer. This terminal layer provides the structural and charge neutrality requirements for electrostatic coupling to the positive -CH3 group of ethanol on the terminal layer of the opposing Ce-CP monolayer. Continued evaporation of ethanol will result in more Ce, regardless of whether the monolayer is permeable or not. 4+ It provides the propulsion force for ions to move toward the surface.

[0387] In this way, multiple monolayers can be stacked to form sheets with a wide range of thicknesses. This is shown in Figure 54, where Ce-CP sheets with various thicknesses ranging from extremely thin (10 nm) to thick (100 nm) were synthesized during reassembly over a period of 6 to 72 hours. The graph of thickness variation as a function of evaporation time is shown in Figure 54, which shows a partially linear tendency in the controllable fabrication of nanosheets with precisely tuned thicknesses. Furthermore, by changing the concentration of Ce-CP as a precursor over a constant reassembly time of 48 hours, Ce-CP nanosheets with different thicknesses are formed (Figure 55).

[0388] Figure 53(c) shows an optical image of a fragmented Ce-CP nanosheet with a lateral size of several hundred microns. Figure 53(d) shows an AFM image of a representative nanosheet collected from the ethanol / air interface after ethanol evaporation at -10°C for 48 hours. The associated height profile shown in the inset of Figure 53(d) revealed a consistent thickness of approximately 48 nm. TEM and the corresponding selected-region diffraction (SAED) patterns, as shown in Figure 53(e) and the corresponding inset, support the presence of polycrystalline Ce-CP nanosheets. Elemental mapping performed by energy-dispersive spectroscopy (EDS) (Figures 53(f)-(k)) indicates that the main elements are Ce and Cl. These nanosheets can be easily transferred to a glass substrate using van der Waals exfoliation techniques.

[0389] From Ce-CP to CeO 2-x The conversion was carried out by elapsed Ce-CP nanosheets in a strongly basic solution (6 M NaOH) at room temperature, followed by heating at 200°C. As a result, the 2D morphology with extensive nanopore formation was retained. Figures 56(a) and (b) show porous CeO 2-x High-angle annular dark-field (HAADF) images of nanosheets are shown. CeO 2-xThe polycrystalline nature of the material is confirmed by the SAED pattern in the inset (Figure 56(b)). A high-resolution TEM (HRTEM) image of the nanosheet (Figure 56(c)) shows crystallites with sizes ranging from 4 to 8 nm, and intercrystallite pores smaller than 10 nm. In addition, strong chemical bonds exist between single crystallites due to the transverse stripe lattice. Figure 56(d) shows CeO 2-x Ce 3+ and Ce 4+ Porous CeO2 suggests the coexistence of both oxidized and porous states. 2-x The XPS spectrum of the nanosheet is shown. As discussed above, Ce 3+ The presence of oxygen vacancy defects (V) is considered to be the active site of the catalyst. O ** This reflects oxygen vacancies ([V O ** The concentration of ]) is Ce 3+ It is indirectly quantified from the amount, which will be discussed later. Figures 56(e) and (f) show highly porous CeO obtained from Ce-CP nanosheets recovered after 10 hours of evaporation. 2-x AFM image (e) and corresponding height profile (f) of the nanosheet are shown.

[0390] 3D Ce-CP hollow pseudo-octahedron and CeO derived therefrom 2-x The role of evaporation kinetics was investigated by rapidly recrystallizing Ce-CP at room temperature while keeping the concentration constant ([Ce-CP] = approximately 8M). Ce-CP can form self-supporting Ce-CP pseudooctahedra. Figure 57(a) shows an SEM image of a self-supporting Ce-CP pseudooctahedra. The pseudooctahedra shown in Figure 57(b), which have variable c-axis lengths and terminate at upward and downward pyramidal structures, are a common crystal form for minerals that crystallize in a monoclinic system. The XRD pattern of the Ce-CP octahedra was identical to that of the Ce-CP rods (Figure 58(a)), confirming that the crystal structure remained unchanged and was not affected by the decomposition / reassembly process. However, the peaks of the hollow pseudooctahedra were broadened compared to those of the rods. The smaller crystallite size of the hollow pseudo-octahedron compared to the Ce-CP rod / tube suggests that the difference in full width at half maximum (FWHM) of the XRD pattern is reasonable (Figure 58(b)). Further supporting evidence was found by laser Raman microscopy and Fourier transform infrared spectroscopy (FTIR), which demonstrated that the chemical structures of the Ce-CP tube and the pseudo-octahedron are identical (Figure 58(c), (d)).

[0391] The time course and transformation of a pseudo-octahedron in a concentrated NaOH solution at room temperature resulted in CeO without morphological changes. 2-x The conversion was performed. This is shown in Figures 57(d) and (e) by SEM images and corresponding schematic diagrams, respectively.

[0392] CeO obtained from Ce-CP 2-x The XRD pattern (Figure 57(f)) was attributed to the cubic fluorite-type structure of CeO2, space group Fm3m. Generally, the conversion from CP to metal oxides is due to the weakly bonded organic linker being OH in aqueous solution. - This is thought to be due to replacement with and / or H2O. Regarding Ce-CP in aqueous solution, Ce 4+ The relatively high electric field strength enhances its Ce(OH)4 formation ability, but this is easily reduced by drying. 2-x It is converted to [this]. After the conversion, thermal decomposition at a temperature above 200°C may be performed. As a result, the crystal plane is formed by the remaining OH -Furthermore, the removal of H2O molecules causes a concave distortion (Figure 57(g), (h)), which leads to improved crystallinity (Figure 57(i)). 2-x SEM images of the pseudo-octahedron revealed the presence of pores formed on the structure (shown as reddish-purple circles in Figure 57(g)). This is supported by dark-field HRTEM images (Figures 57(j), (k)) which identify a cluster of pores approximately 10 nm in size. The extended rings in the selected-region diffraction (SAED) pattern (inset in Figure 57(j)) are polycrystalline CeO 2-x It shows a disorderly oriented structure. The BET surface area of ​​the hollow pseudo-octahedron is 47.18 m². 2 g -1 The measurements showed a pore size of 6.86 nm and a pore volume of 0.42 cm³. 3 / g -1 That was the case.

[0393] The second crucial factor controlling structural reassembly is the Ce-CP concentration. In principle, the supersaturation factor (S) of the major ion concentration in solution is determined by the following equation:

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[0394] 3D Ce-CP hollow spherical bodies and CeO derived therefrom 2-x Another decisive factor is the ionization (α) of Ce-CP, which represents the amount of Ce-CP dissociated. This value is considered to be approximately 1, since Ce-CP completely decomposes in ethanol.

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[0395] The proposed mechanism for spherical formation is based on the swelling of nanosheets during the evaporation of interlayer ethanol, which is schematically shown in Figure 59(d). To support the proposed mechanism, experimental conditions were designed to accelerate evaporation, which contributes to the formation of hemispheres preceding spherical formation and exfoliation. 3D AFM images and corresponding height profiles are shown in Figures 59(e) and (f), respectively. The hemispheres have a diameter of approximately 600–700 nm (height of approximately 10–25 nm), which is larger than the diameter of the spherical bodies (approximately 200–400 nm), as shown in Figure 60. This is thought to be due to the gradual contraction of the former during the formation of the latter.

[0396] Similarly, Ce-CP is converted to CeO using the time course of NaOH and thermal decomposition at 200°C. 2-x It was converted into a sphere. CeO 2-xThe hollow spherical bodies had a diameter of 200-400 nm and a wall thickness in the range of approximately 28-0 nm. 2-x SEM images of the hollow spherical body are shown in Figures 5a-c, which clearly show that the hollow spherical body has a diameter of 200-400 nm. TEM images of CeO are shown in Figures 60(d) and (e). 2-x The hollow structure is observed, with the wall thickness of the spherical bodies ranging from approximately 28 to 40 nm. These thicknesses appear to be approximately half the thickness of the original nanosheet. HRTEM images of individual hollow spherical bodies (Figure 60(d)) are shown in Figure 60(e), where crystallites with exposed crystal planes (111) and (100) were identified. The SAED pattern of the hollow spherical bodies, as shown in Figure 60(g), is attributed to CeO2, and the rings support a polycrystalline structure. Furthermore, Figures 60(h) and (i) show CeO2 2-x This shows the EDS mapping of Ce and O in a hollow spherical body.

[0397] Figure 60(j) shows the Raman spectrum of Ce-CP, as well as the time course and heating process of CeO 2-x This shows the effect on derived Ce-CP. After the NaOH time elapsed, 455 cm -1 The peaks were attributed to the F2g vibrational modes of Ce and O. However, the asymmetric nature of the peaks and the red shift are due to V in the structure. O ** This is thought to be due to the presence of charge compensation (V O ** This is supported by three broader, lower-intensity peaks suggesting ) . After heating at 200°C, a single narrow peak indicates relatively good crystallization of CeO 2-x This suggests that the remaining compression and V O ** 464cm caused by the annihilation of two -1 The blue color indicates the shift (higher value) of the F2g peak located at [this point].

[0398] Overall Ce-CP formation mechanism The tuning of the structure of the nanostructures of this disclosure, and the resulting performance, may be accidental due to the use of unstable CP. The methods of this disclosure generally provide rapid yet variable decomposition / reassembly kinetics by generating new nanostructures at room temperature using various solvents. For example, immersion of Ce-CP in deionized water causes the Ce-CP to gradually detach, as shown by extrasystem TEM imaging and the schematic diagram in Figure 1-h. Decomposition occurs due to interlayer insertion of water molecules between terminal Cl ions on the Ce-CP nanosheet. Furthermore, deionized water does not act as a solvent due to its different polarity index. The same results are obtained by applying the same method to Zr-CP and Ti-CP, thus highlighting the universality of the methods of this disclosure.

[0399] In contrast, weakly polar solvents such as ethanol induce very rapid decomposition / reassembly of Ce-CP. This solubility indicates that Ce-CP has a similar degree of intermediate polarity as a solvent. The tendency for very rapid structural changes of Ce-CP at room temperature is demonstrated by the decomposition of tubular Ce-CP nanostructures within 1.5 minutes and their rapid reassembly into octahedral form during ethanol evaporation. In addition, in-situ Raman spectroscopy revealed changes in the vibrational modes of structural bonds during the decomposition / reassembly of Ce-CP. The Raman spectrum after 360 seconds showed no trace of ethanol, supporting the conclusion that ethanol merely acts as a medium for the decomposition and reassembly of Ce-CP nanostructures. Such behavior was also observed in MOF-5 nanostructures, with different experimental conditions yielding a variety of ZnO nanostructures.

[0400] The decomposition kinetics of unstable CPs may be driven by (i) a high cationic charge and, consequently, a high electric field strength that favors hydroxide formation at high pH, ​​(ii) a tendency of the linker to be protonated in low pH aqueous solvents, thereby replacing the linker with a hydroxyl group, (iii) a linker with low molecular symmetry (monodentate, bidentate, etc.), and (iv) polarity agreement between the solute and the solvent. In the case of Ce-CP, Ce 4+The electric field strength is relatively strong, which is therefore more favorable to forming bonds with hydroxyl groups than with monodentate trichloroacetate (TCA) linkers, effectively destabilizing any Ce-TCA bond. The solvents exhibiting the fastest kinetics are those with polarity indices in the range of 4.3 to 5.9, indicating that the polarity indices of Ce-CP fall within this intermediate range. Furthermore, the reassembly kinetics of the new nanostructures are mainly determined by the partial pressure of the solvent, which can be manipulated by temperature and chemical potential. For example, hollow octahedra are formed when ethanol evaporates rapidly at room temperature, while hollow spheres are formed when evaporation occurs at 0°C.

[0401] Figure 61 shows various nanostructures obtained as a function of [Ce-CP], with Figure 4(ad) showing the Ce-CP nanostructure and Figure 59(e~h) showing the CeO obtained by time progression in NaOH and heating at 200°C. 2-x This shows that Ce-CP as a function of increasing [Ce-CP], and therefore CeO 2-x The structural changes follow the order of nanosheet, hollow sphere, hollow pseudo-octahedron, hollow elongated octahedron, and dense foil.

[0402] The model of stacked flat nanosheets presented in Figure 53 is supported by the presence of ridges, which are clear in Figures 61(f) and (g) and faintly visible in Figures 61(h) and 55. Ultimately, the collision of the elongated octahedral morphology shown in Figure 61(g) results in the formation of the dense foil morphology shown in Figure 61(h). This dense state arises from an increase in [Ce] and, consequently, a decrease in diffusion distance. All nanostructures in Figure 61 were generated at low temperatures (25°C), and therefore the driving force of diffusion was low. This worked in favor of forming polycrystalline structures rather than single crystals. Consequently, the flexibility to generate various nanostructures suggests structural changes due to phase transformations by low-energy substitution rather than high-energy reconstruction.

[0403] CeO 2-xFurther morphological analysis is shown in Figure 62. Figure 62(h) contains a large amount of single crystal CeO 2-x The identification of pyramidal structures, combined with the presence of ridges on the pseudo-octahedrons, suggests that these morphologies arose from interlocking hemispheres still bonded to nanosheets present along the diameter (Figure 61(a)). This process can be proposed to occur through the formation of ridges from the fracture surface of the flexible Ce-CP monolayer, followed by the early formation of crystal planes through the planarization of the rounded hemispheres. As suggested in Figure 61(a), the pyramidal structures are formed before separation from the nanosheets due to the presence of maximum diametrical stress at the circle of greatest sheet mismatch. Although individual pyramidal structures would have been formed by complete delamination, the nanosheets and elongated octahedra are formed by different mechanisms. These structures may have been generated by chemical gradient fluctuations resulting from the periodic evaporation and replenishment of ethanol while the two hemispheres remained in proximity. This view is supported by a more detailed visual examination of Figure 61(g), which shows that the central ridge of the elongated octahedron is the most inconsistent, suggesting the closure of two interlocking pyramids in the final stage of evaporation-concentration.

[0404] The general formation mechanism of the microstructure is shown in Figure 63. The recrystallization of aggregates from electrolytes containing both cations and anions, which are constituent elements, is governed by the aforementioned equation. 2It is known that the ionization (α) and supersaturation factor (S), which are represented by , are determined by . With respect to α, the solvent ethanol and solute Ce-CP, which have a high degree of dissociation, are single variables, and therefore the ionization factor is fixed in principle. Nevertheless, α during recrystallization changes with temperature fluctuations, which alters the ethanol evaporation rate. Similarly, with respect to S, changes in the Ce-CP concentration during evaporation also lead to changes in the S value. Consequently, the formation of polycrystalline 2D and 3D structures depends on the synergistic control of both the α and S factors. Such control by a single experimental variable allows for systematic and precise changes in morphology from 2D to 3D. More specifically, evaporation kinetics characterized by low α and S factors lead to the formation of ultrathin 2D Ce-CP nanosheets. If a low α factor is maintained but the S factor increases, an increase in nanosheet thickness occurs. When the α factor increases due to evaporation at room temperature, the increase in S leads to a 3D structural change in the following order: hollow sphere, hollow pseudo-octahedron, hollow elongated pseudo-octahedron, and finally solid foil.

[0405] Overall, the metal-based CP (MCP) treatment method is a simple, cost-effective, and mold-free low-temperature method (below 25°C) for producing metal oxides with unprecedented structures. This method involves the oxidation of cerium-based MCP, which enables rapid decomposition / reassembly in the polar solvent ethanol, thus producing highly functional, reliable porous 2D and hollow 3DCeO 2-x Nanostructures are obtained. Porous 2D metal oxides with precisely controlled thicknesses were obtained by manipulating the kinetics of MCP nucleation / growth.

[0406] Example 7: Photocatalytic activity of nanostructures Photocatalytic parameters CeO 2-xTo investigate the photocatalytic parameters of the mixed nanostructure, corresponding electronic band structures were constructed. Therefore, the gap between the valence band (VB, orange line) and the Fermi level (Ef, black dashed line), the optical indirect transition band gap (Eg), and the work function (Φ) were determined using XPS, UV-Vis spectrophotometry, and amplitude-modulated Kelvin probe force microscopy (AM-KPFM). The AFM image in Figure 5a is shown in Figure 5b for CeO 2-x This shows the baseline for KPFM results. A silicon substrate (higher potential) and a 1.2 nm thick layer of deposited CeO2. 2-x A large potential difference of 90mV (0.09eV) exists between the nanosheet (lower potential) and the silicon chip. The Φ of the platinum / indium coated silicon chip was measured to be 4.74eV (similar to previously reported values), so by subtracting 0.09eV, we can determine the CeO 2-x A Φ of 4.65 eV is obtained. The existence of a trapped state within the band gap was also shown for CeO 2-x The XPS graph of the valence band of is shown in Figure 5c. In addition, the Tauc plot of Eg is shown in Figure 5d. These data, as well as Fe2O3 / Fe3O4-CeO 2-x Using data from nanostructures (FCO), NCO, and ZCO (Figures 44 and 45), the electron energy level diagram shown in Figure 5e was constructed.

[0407] The above demonstrates that these porous 2D nanostructures offer the dual advantages of rapid charge-carrier diffusion and a significant reduction in Eg from 3.36 eV to 2.89 eV. Furthermore, V O ** and V Ce ”” There exists a potential in which the influence of a mid-gap trap state (Figure 5c) related to the presence of exists, although the position of the corresponding energy level does not appear to be fixed. Figure 5e shows that the photocatalytic ability for a particular chemical reaction can be manipulated by modifying the electron band structure by creating nanostructures. For example, Figure 5e shows that FCO lowers Eg to 2.50 eV and CeO 2-x The CB (green line) is above that of Fe2O3 / Fe3O4 and also O2 / ·O2 -This indicates that it is positioned above the energy level. Reducing the band gap significantly increases light absorption, O2 / ·O2 - The new CB position of the FCO near CeO 2-x The activation of electron transfer from to Fe2O3 / Fe3O4 enhances the formation of reactive oxygen species (ROS). The alignment of the VB and CB bands also suggests that both electron and hole charge transfer is toward Fe2O3 / Fe3O4, and therefore charge recombination is enhanced. However, electron / hole recombination in mixed OD / 2D heterostructures is CeO 2-x PL spectroscopy confirmed a decrease compared to nanosheets (Figure 46). These data suggest that charge transfer is dominant over electron / hole recombination due to the short diffusion pathways in nanosheets.

[0408] XPS analysis of NCO and ZCO nanostructures (Figure 44) also showed the formation of a trapped state. The band gaps of NCO and ZCO increased (Figure 5e), but the CB of NCO, and the VB of both NCO and ZCO, remained O2 / ·O2, respectively. - And are appropriately positioned to catalyze the ·OH / H2O reaction, thereby enhancing the formation of each ROS. Furthermore, both VB and CB are CeO 2-x Compared to those, the charge separation is reduced, and electron diffusion to TMO and CeO 2-x This suggests that the problem will be improved by hole diffusion.

[0409] To further evaluate the differences in electronic band structure between CeO2 nanosheets, bulk CeO2, and 0D / 2D heterostructures, first-principles calculations based on DFT were performed. Figure 5f shows that the band gap of CeO2 nanosheets is reduced by approximately 10% compared to that of bulk CeO2, which is in excellent agreement with experimental results (Figure 5d). When transition metal ions are adsorbed, a significant change in the band structure of CeO2 nanosheets is observed (Figures 5g-i), with new electronic states appearing within the band gap and, in one case, at the bottom of the conduction band (Figure 5g); the band gap is in good agreement with experimental data (Figure 5e). The origin of such differences in band structure is supported by the differences in the calculated transition metal adsorption energies, which are -10.8 eV (Fe), -3.8 eV (Ni), and -0.1 eV (Zn). Larger charge transfers typically correlate with more favorable adsorption energies, and therefore, different attractive electrostatic interactions result in large differences in the amount of charge that transition metal ions transfer to the nanosheet (approximately 2e per Fe ion). - Approximately 1e per Ni - , and approximately 0e per Zn - These fluctuations suggest the possibility of broad band tuning through the formation of 0D / 2D heterostructures using different ions.

[0410] CeO based on heterojunction structure 2-x Figure 46 shows the room-temperature luminescence (PL) emission. At FCO, the peak intensity drops to near zero, indicating minimal electron / hole recombination due to rapid charge carrier separation via a very short diffusion pathway. The broad emission band located at approximately 450 nm is caused by surface oxygen vacancies and atomically thin CeO 2-x This confirms the high concentration of oxygen vacancies in porous nanosheets. Adding NiO and ZnO significantly reduced the UV emission peak near the band edge, while simultaneously shifting it towards deep-level (DL) emission within the green wavenumber range. This decrease is attributed to Ni 2+ and Zn 2+ The band electrons of the localized d electrons and CeO 2-xThis is thought to be due to sp-d exchange interactions with the nanosheets. Furthermore, the high intensity of PL emission in both NCO and ZCO indicates an increase in defect concentration. The increase in defect concentration can also be confirmed by determining the trapping sites from the XPS valence band results (Figure 44). For NiO, the green emission band at 560 nm indicates defects in the NiO lattice, such as Schottky pair defects, interstitial oxygen traps, and Ni 2+ Ions and Ni 3+ This is thought to be due to nickel vacancies generated by charge transfer between ions. In ZCO, the small, broad emission peak at 390 nm is thought to be due to the recombination of free excitons via exciton-exciton collisions, but this is not very significant in any heterojunction nanostructure. The weak, broad blue emission band at approximately 460 nm is deep-level emission (DLE) caused by oxygen vacancies or interstitial zinc ions in the ZnO nanomaterial. A broad green emission band was observed at 550 nm in all ZnO nanomaterials, which may be due to the presence of defects such as monovalent ionized oxygen vacancies.

[0411] CeO 2-x The functionality of nanostructures depends on their defect content.

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[0412] Catalyst performance The photocatalytic performance of the samples was evaluated under sunlight irradiation by decomposition analysis of methylene blue (MB) compounds, which are widely used for photocatalytic analysis. (664 cm² in the presence of nanosheets) -1 The gradual decrease in the intensity of the absorbance peak of MB centered on was measured. 2-x The nanosheets exhibited a high degree of pigment degradation of 85% after 2 hours (Figure 47), but the reaction kinetics were 0.024 min, which corresponds to the fastest reported pigment degradation using pure CeO2. -1 The rate constant (k) for each height was determined (Table 4). The 0D / 2D heterostructures performed even better, with FCO, NCO, and ZCO reaching 100%, 94%, and 90% respectively after 2 hours with correspondingly higher rate constants. High stability of the samples was observed after the photocatalytic testing.

[0413] Figure 47(a) shows the absorption spectra corresponding to the mixed nanosheets and MB solution as a function of irradiation time. The considerable decrease in the absorption peak in the first 40 minutes indicates rapid chemical decomposition of MB, followed by the almost complete loss of the peak after 2 hours. As shown in Figure 47(b), using a pseudo-first-order reaction model, A t Let ln(A) be the dye absorbance at time (t) and A0 be the dye absorbance before irradiation. tThe kinetics of photodegradation were investigated by plotting the / A0) against irradiation time. In addition, Figure 47(c) shows a graph comparing the dye degradation performance of the porous nanosheet synthesized in this study with the best performance previously reported. The experimental conditions of the study are summarized in Table 4. Furthermore, FCO, which has a band gap in the visible light region, shows enhanced dye degradation performance with a remarkable nearly 100% degradation after 2 hours (Figure 47(d)).

[0414] The performance of nanosheets can be attributed to two mechanisms: 1) High density of structural defects that modify the electronic properties of the nanosheets by narrowing the band gap. The atomic layers of the nanosheets provide a high surface-to-volume ratio, which significantly enhances the exposed crystalline planes in the dye-nanosheet interface region. 2) This performance has been shown to be greatly improved by the fabrication of mixed heterojunction nanostructures that minimize the density of electron / hole recombination, introducing numerous defects that act as active sites, thereby catalyzing dye degradation by resulting in numerous ROS in solution. [Table 5]

[0415] Furthermore, CeO 2-x Complete CO oxidation at approximately 150°C using a 2D-3D scaffold, and its subsequent reduction to approximately 90°C through modification as a CeO2-based hybrid, result in the lowest temperatures for CO oxidation ever reported (see Table 5). [Table 6]

[0416] Various CEOs 2-x Catalyst performance of form Various CEOs 2-xThe catalytic performance of nanostructures was compared by testing their activity in CO oxidation. The results in Figure 64 show that the CO conversion rate decreases in the order of ultrathin sheet > pseudo-octahedron > sphere > foil. For example, at 400°C, these values ​​were 21.1, 12.8, 1.93, and 0.0 mol g, respectively. -1 s -1 The turnover frequency (TOF) values ​​calculated for each catalyst at this temperature, based on the CO molar ratio, are as follows: (surface area = 81 m²) 2 ·g -1 Pore ​​volume = 0.32 cm³ 3 g -1 ) is 4.4 × 10 -3 mol mol -1 s -1 This shows that it exhibited the highest TOF value, which is a pseudo-octahedron (surface area = 47 m²). 2 ·g -1 Pore ​​volume = 0.42 cm³ 3 g -1 This value for nanosheets is 1.5 times higher than that for spherical bodies (surface area = 53 m²). 2 ·g -1 Pore ​​volume = 0.15 cm³ 3 g -1 It is also 5 times the value of the foil (surface area = 6m²). 2 ·g -1 Pore ​​volume ≈ 0 cm³ 3 g -1 This value is approximately 50 times greater. These results support the idea that the combination of surface and pore volume reflects the density of active sites consisting of unsaturated coordination bonds that enhance CO adsorption. Furthermore, it is important that the nanostructure is polycrystalline, as V is present as a point defect along the grain boundaries. O ** This is because it has been shown to be present in high concentrations.

[0417] The activation energy (E) of CO oxidation for various nanostructures aTo determine the catalyst kinetics, we also evaluated them using Arrhenius plots. As expected, these followed the same relative order as the CO conversion rates, with TOF increasing to 47 < 58 < 115 < 134 kJ / mol for ultrathin sheets, pseudo-octahedrons, spheres, and foils, respectively. The high [V] of the CeO2 samples obtained from quantitative analysis of XPS results in Figures 65 and 66. O ** It is important to note that [these play an important role in catalytic activity by facilitating CO adsorption and accelerating the mobility of lattice oxygen, thereby enhancing CO2 desorption.]

[0418] The CeO prepared in this specification 2-x The photocatalytic performance of the form is measured at an illuminance of 100 mW / cm². 2 This was studied by photodecomposition of MB during AM1.5G sunlight irradiation. 664cm² -1 The maximum intensity of the absorbance peak was used as the criterion for comparative evaluation, and the data is shown in Figure 67(a). Figure 67(b) reveals that there are three performance levels for dye decomposition: high (84% porous nanosheet), medium (55% pseudo-octahedron, 40% spherical), and low (16% foil). These data are consistent with CO oxidation activity and suggest that surface properties and pore volume play the main roles in catalytic activity.

[0419] Absorbance at time t (A0) relative to absorbance at initial time t Figure 67(c) shows the kinetics of decomposition by porous nanosheets plotted against irradiation time, converted to a ratio of ). The only other published value obtained under similar test conditions is 0.003 min. -1 and 0.012 min -1 The decomposition rate constant (k) that can be compared to this is 0.014 min -1 This was decided. Pure CeO 2-x The high efficiency observed is thought to be due to two main factors. First, the porous, thin nanostructure provided high reach of charge carriers to the active site due to the short diffusion distance from bulk to surface. This desirable property is attributed to Ru3Al

[42] and Ni(OH)

[43] The porous nanosheet catalysts, as previously reported, resulted in a reduction in charge carrier recombination time, which led to enhanced hydrogen and oxygen evolution reactions (HER and OER, respectively). Secondly, XPS data identified the active sites involved in the reaction [V O ** The high calculated value of [ ] (Figure 65) reveals a high area density of the active site.

[0420] Figure 67(d) shows various pure and hybrid CeO2s with variable sizes. 2-x This shows a series of publicly available values ​​from photodegradation tests conducted on the morphology. The superiority of the porous nanosheet morphology is demonstrated by the degree of degradation. Furthermore, the analysis revealed that various CeO2 morphologies with crystallite sizes of 20 nm or less ranged from 2 to 65 nm. 2 ·g -1 The study revealed that the BET specific surface area was in the range of 4-8 nm and the degree of photodegradation was in the range of approximately 4-70%. These values ​​correspond to the crystallite size in the range of 4-8 nm and 81 nm. 2 ·g -1 The specific surface area and the value of the porous nanosheet form, which exhibited outstanding photodegradation performance of 77%, can be compared. The latter is CeO 2-x This represents the best performance ever reported. Comparing the data from this study, the effect of the reachable active site is clearly dominant, most evident in the relationship between specific surface area and pore volume, which are predictors of performance.

[0421] Structure, defect equilibrium and nanostructures are CeO 2-x The effects of the oxygen vacancy concentration ([V) on the catalytic and photocatalytic performance are summarized in Figure 68, which shows the effects of the oxygen vacancy concentration ([V) on the catalytic and photocatalytic performance of the four forms. O ** The graph plots the surface area, specific surface area, and pore volume. These data are used to determine the CO conversion rate, turnover frequency, and required activation energy (E). a) and photodegradation are compared with the data presented in the table. These data showed that the primary factor controlling performance is the specific surface area, which reflects the density of the active sites. Table 6 shows comparative data between this study and other equivalent studies, where the dominant effect of surface area is also confirmed. However, the inconsistent trend between pseudooctahedrons and spheres indicates that this parameter is mitigated by the effects of oxygen vacancy concentration and pore volume. Finally, there is no direct correlation between morphology and oxygen vacancy concentration, which is concentrated in crystallites and grain boundaries. Such a correlation is not found in single-crystal CeO 2-x While this has been observed in previous studies, the discrepancies with this research highlight the effect of these structures being polycrystalline.

[0422] Overall, porous 2D CeO 2-x The nanostructures exhibited outstanding photocatalytic performance. These catalytic properties may be derived from short charge carrier diffusion pathways and low recombination densities, which are associated with thin, porous, polycrystalline nanosheets containing high concentrations of active sites.

[0423] Example 8: Metal sulfide nanostructures Ce-CP is a hybrid CeO2 with carbon and sulfur incorporated. 2-x It can be used as a precursor for forming a system macrolayer (Ce / S / C).

[0424] The structural study of the conversion from Ce-CP to Ce / S / C was conducted using XRD and Raman analysis, and the results are shown in Figure 70. The XRD data confirms that the decomposition / reassembly of Ce-CP using DMSO preserves the triclinic structure of pure Ce-CP. Annealing of the reassembled Ce-CP in air and N2 atmosphere resulted in oxidation to a CeO2 fluorite-type structure. The Raman spectra obtained for Ce-CP and DMSO-derived Ce-CP (Figure 70b) show the α of SO4 in the sulfuric acid Ce structure. g 1040cm, which is thought to be due to the vibration mode. -1 This reveals the main peak located at 450cm. -1 and 470cm -1As suggested by the decrease in intensity of adjacent peaks in the COO of Ce and TCA - The number density of bonds with the group decreased significantly after reassembly.

[0425] When DMSO-derived Ce-CP was annealed in an air and N2 atmosphere, CeO2 with carbon incorporated into its structure was obtained. (1300 cm) -1 and 1600cm -1 The two peaks are the D-mode and G-mode, which support the presence of graphitic carbon. It is important to note that the F2g mode, due to stretching vibrations between Ce and O in CeO2, appeared in the spectra for both air and N2. However, in CeO2 obtained in air, this peak is lower (457 cm⁻¹). -1 The position shifted to ). This may be due to the presence of the E1g vibrational mode of the SO4 group in the sulfuric acid Ce structure. The Raman spectrum of the sample calcined in air also shows 1057 cm⁻¹, which is thought to be due to SO4. -1 A small peak is observed. These results indicate that the formation of carbon-sulfur heterostructures in hybrid CeO2 systems involves a two-step process of reassembly and post-oxidation.

[0426] Further analysis by XPS surface characterization is shown in Figure 71. The variation in Cl concentration is shown in Figure 71a; the intensity of the Cl 2p orbital remained unchanged in Ce-CP and DMSO-derived Ce-CP, while calcination in both air and N2 resulted in almost complete removal. In Figure 71b, XPS analysis of the C 1s orbital revealed similar differences between Ce-CP and DMSO-derived Ce-CP, with COC bonds (286 eV) and OC=O bonds (289 eV), respectively, although the former was increased by the introduction of DMSO into the structure. Calcination of DMSO-derived Ce-CP almost completely eliminated the less stable O=C bond, although a small amount of such bond remained, shifting to a higher bond energy due to the increased covalent nature of the CC bond upon removal of the highly electronegative Cl group. The presence of a dominant 286 eV peak may suggest the formation of a graphite structure. Firing in N2 revealed higher peak intensity, suggesting the formation of a higher graphite-carbon concentration compared to that obtained in air.

[0427] This is confirmed by the XPS analysis of the S 2p orbital shown in Figure 71c. S 2p at 169 eV 3 / 2 As confirmed by the peak, the use of DMSO solvent led to the formation of Ce sulfate. This peak is consistent with what has been reported for cerium sulfate (Ce(SO4)2) where the sulfur oxidation state is +6. The structure of Ce(SO4)2 remained unchanged during calcination in air. On the other hand, calcination in N2 resulted in the appearance of a peak centered at a lower energy of 164 eV, which is thought to be due to sulfur with an oxidation state of +4, suggesting the formation of CeO2 / SO2.

[0428] S occurring simultaneously under N2 6+ From S 4+ Reduction to Ce 3+ From Ce 4+ Oxidation to is an electron exchange reaction: S 6+ +2Ce 3+ →S 4+ +2Ce 4+ This suggests the possibility of IVCT. The feasibility of IVCT is supported by XPS data, as shown in Figures 72a and 72b. However, the corresponding XPS data does not show that this reaction occurs after firing in air. Therefore, under N2, S 6+ From S 4+ It is possible to reduce to Ce 3+ From Ce 4+ Simple oxidation to facilitates IVCT as a means of charge transfer between CeO2 and the sulfate structure. In contrast, under air, S 7+ The absence of a valence state means that S is not S 8+ Oxidation to is effectively prevented, and therefore Ce 3+ Ce via IVCT 4+ It cannot be oxidized to , the latter of which is supported in Figures 72a and 72b. The above results indicate that calcined N2 leads to the formation of a CeO2 / graphitic oxygen / sulfuric acid Ce heterojunction structure.

[0429] The concentration of structural defects associated with the new heterojunction Ce / S / C and pure CeO2 was evaluated using EPR, and the data is shown in Figure 73. The ultrafine pattern in Figure 73a indicates the presence of seven types of defects in the heterostructure compared to pure CeO2, and the area in Figure 73b indicates the presence of a very high concentration of total defects.

[0430] Those skilled in the art will recognize that many changes and / or modifications can be made to the present invention, as shown in the specific embodiments, without departing from the broadly described spirit and scope of the invention. Therefore, the embodiments of the present invention should be considered in all respects as illustrative rather than restrictive.

[0431] All publications discussed and / or referenced herein are incorporated herein by reference.

[0432] Any discussion of documents, actions, materials, apparatus, articles, etc., contained herein is intended solely to provide context for the present invention. The fact that such discussions existed prior to the priority date of any claim of this application should not be construed as acceptance of any or all of these matters forming part of the foundation of the prior art or being common general knowledge in the relevant art of the present invention. (Note) (Note 1) A layered metal coordination polymer comprising two or more layers, Each layer contains metal atoms coordinated to an organic linker in order to form a metal-coordinate polymer layer; where the organic linker is defined by formula 1: XR 1 (1) Selected from one or more compounds having the structure, During the ceremony: X is the metallic bonding portion that coordinates to the metal atom; and R 1 The layered metal coordination polymer is a H, or an optionally interrupted alkyl, alkenyl, or alkynyl group substituted in one or more portions to form the layered metal coordination polymer by forming electrostatic interactions with adjacent metal coordination polymer layers. (Note 2) A layered metal-coordinate polymer, which is a reaction product of an organolinker and a source of metal atoms, The layered metal coordination polymer comprises two or more layers, each layer containing a metal atom coordinated to one or more organic linkers in order to form a metal coordination polymer layer; In the formula, the organic linker is defined in formula 1: XR 1 (1) A compound having the structure is selected, During the ceremony: X is the metallic bonding portion for coordinating with the metal ion; and R 1The layered metal coordination polymer is a H, or an optionally interrupted alkyl, alkenyl, or alkynyl group substituted in one or more portions to form the layered metal coordination polymer by forming electrostatic interactions with adjacent metal coordination polymer layers. (Note 3) The layered metal coordination polymer forms the layered metal coordination polymer, and each R of the organic linker in each metal coordination polymer layer 1 A plurality of metal coordination polymer layers are scattered between the one or more portions of the arbitrarily interrupted alkyl, alkenyl, or alkynyl groups that form the electrostatic interaction between them. Rayville A layered metal coordination polymer containing ions, as described in Appendix 1 or Appendix 2. (Note 4) R 1 However, the metal coordination polymer layers are scattered between them. Rayville The layered metal coordination polymer according to Appendix 3, wherein the layered metal coordination polymer is an optionally interrupted alkyl, alkenyl, or alkynyl group terminated at one or more portions for forming electrostatic interactions with ions to form the layered metal coordination polymer. (Note 5) The aforementioned Rayville The ions are each R of the organic linker in each metal coordination polymer layer. 1 The layered metal coordination polymer according to Appendix 3 or Appendix 4, wherein the charge is opposite to the charge of the one or more terminal portions of the arbitrarily interrupted alkyl, alkenyl, or alkynyl groups. (Note 6) The aforementioned Rayville Ions and each R of the organic linker in each metal coordination polymer layer 1 The layered metal coordination polymer according to any one of appendices 3 to 5, wherein the electrostatic interaction between the one or more terminal portions of the optionally interrupted alkyl, alkenyl, or alkynyl groups is substantially orthogonal to the coordination bonds in the metal coordination polymer layer. (Note 7) The layered metal coordination polymer described in any one of the appendices 1 to 6, wherein the layered metal coordination polymer has a zeta potential greater than zero (0) mV. (Note 8) The layered metal coordination polymer described in any one of the appendices 1 to 7, wherein the layered metal coordination polymer has a zeta potential of about 10 mV to about 60 mV. (Note 9) Each R of the aforementioned organolinker 1 The alkyl group is optionally interrupted by one or more O, N, S, Se, Te, Si, aryl, heteroaryl, and / or cycloalkyl groups. 1-10 A layered metal-coordinate polymer, which is an alkyl group, as described in any one of the appendices 1 to 8. (Note 10) Each R of the aforementioned organolinker 1 The alkyl group is optionally interrupted by one or more O, N, S, Se, Te, Si, aryl, heteroaryl, and / or cycloalkyl groups. 1-6 A layered metal-coordinate polymer, which is an alkyl group, as described in any one of the appendices 1 to 9. (Note 11) Each R of the aforementioned organolinker 1 The layered metal coordination polymer according to any one of the appendices 1 to 10, wherein one or more portions of the optionally interrupted alkyl, alkenyl, or alkynyl groups comprise one or more halogens selected from the group consisting of F, Cl, Br, and / or I, or one or more halides selected from the group consisting of Li, Na, K, Rb, and / or Cs. (Note 12) The layered metal coordination polymer according to any one of the appendices 1 to 11, wherein the metal bonding portion (X) is a monodentate, bidentate, or polydentate ligand. (Note 13) The layered metal coordination polymer according to any one of the appendices 1 to 12, wherein the metal bonding portion (X) is a monodentate or bidentate ligand. (Note 14) The layered metal coordination polymer according to any one of the appendices 1 to 13, wherein the metal bonding portion (X) is a monodentate or bidentate ligand that forms a bridging coordination bond with two or more metal atoms to form the metal coordination polymer layer. (Note 15) The layered metal coordination polymer according to any one of the appendices 1 to 14, wherein the metal bonding portion (X) comprises a carboxylate, an amine, a hydroxyl, a thiol, and a nitrile. (Note 16) The layered metal coordination polymer according to any one of the appendices 1 to 15, wherein the metal bonding portion (X) contains a carboxylate. (Note 17) The layered metal coordination polymer according to any one of the appendices 1 to 16, wherein the organic linker is formic acid, trifluoroacetic acid, trichloroacetic acid, tribromoacetic acid, or triiodoacetic acid. (Appendix 18) The layered metal coordination polymer according to any one of the appendices 1 to 17, wherein the metal atoms are selected from one or more of the rare earth metals, transition metals, Group 13, Group 14, or Group 15 metals of the periodic table. (Note 19) The layered metal coordination polymer according to any one of the appendices 1 to 18, wherein the metal atom is a metal ion. (Note 20) The layered metal coordination polymer according to Appendix 19, wherein the metal ions are monovalent or polyvalent. (Note 21) The layered metal coordination polymer according to Appendix 20, wherein the metal ions are monovalent or polyvalent and are one or more metals selected from rare earth metals, transition metals, Group 13, Group 14, or Group 15 metals of the periodic table. (Note 22) The aforementioned metal ions, Ce 3+ Ce 4+ Ti 4+ , Zr + or Zn + The layered metal coordination polymer described in Appendix 20 or Appendix 21. (Note 23) The layered metal coordination polymer according to any one of the appendices 1 to 22, wherein the metal coordination polymer is a cerium metal coordination polymer having the formula Ce(TCA)2(OH)2·2H2O. (Note 24) The layered metal coordination polymer according to Appendix 23, wherein the cerium metal coordination polymer is characterized by an X-ray powder diffraction (XRD) pattern containing one or more major peaks located at approximately 7.2, 8.1, 10.9, 20.6, 22.0, 23.1, and 23.2°(2θ). (Note 25) A layered metal coordination polymer according to any one of the appendices 1 to 24, wherein each metal coordination polymer layer may independently have an axial thickness along the c-axis of approximately 11.0 nm, 5.5 nm, 2.2 nm, or 1.1 nm. (Note 26) The layered metal coordination polymer according to any one of the appendices 1 to 25, wherein the layered metal coordination polymer is polycrystalline. (Note 27) A process for preparing a layered metal-coordinate polymer comprising two or more metal-coordinate polymer layers, as defined in any one of the appendices 1 to 26, The process involves combining a metal atom source with an organic linker to form a layered metal-coordinate polymer containing two or more metal-coordinate polymer layers that are held together by electrostatic interactions. The process including the process described above. (Note 28) The process according to Appendix 27, wherein the step of combining a metal atom source and an organic linker includes mixing an aqueous solution containing the metal atom source and the organic linker to form a layered metal coordination polymer comprising two or more metal coordination polymer layers held together by electrostatic interaction. (Note 29) The process according to Appendix 27 or Appendix 28, wherein the step of forming the layered metal coordination polymer includes hydrothermal treatment or electrodeposition. (Note 30) The process described in Appendix 29, wherein the electrodeposition is modified anodic chronoamperometric electrodeposition (MACE). (Note 31) The process according to Appendix 29 or Appendix 30, wherein the initial pH of the aqueous solution during electrodeposition is less than approximately 7. (Note 32) The process according to Appendix 29 or Appendix 31, wherein the initial pH of the aqueous solution during electrodeposition is approximately pH 2 to approximately pH 7. (Note 33) The process according to any one of the appendices 28 to 32, wherein the concentrations of the metal atom source and the organic linker in the aqueous solution are independently about 0.001 M to about 1 M. (Note 33) The process according to any one of the appendices 29 to 32, wherein the electrodeposition is carried out within the oxygen-evolving region of the aqueous solution containing the metal atom source and the organic linker. (Note 34) The process according to any one of the appendices 29 to 33, wherein the electrodeposition is carried out using a constant applied voltage effective in maintaining the oxygen-evolving region of the aqueous solution containing the metal atom source and the organic linker. (Note 35) The electrodeposition is carried out using a constant applied voltage of 1mV to 10V paired with Ag / AgCl, as described in Appendix 34. (Note 36) The electrodeposition is carried out at a temperature of approximately 0°C to approximately 100°C for a fixed period of approximately 1 minute to approximately 90 minutes, as described in any one of the appendices 29 to 35. (Note 37) The electrodeposition involves one or more of the metal coordination polymer layers scattered between them. Rayville Ions are generated, and each R of the organic linker in each metal coordination polymer layer 1 The process according to any one of the appendices 29 to 36, wherein the electrostatic interaction is formed between one or more optionally interrupted alkyl groups to form the layered metal coordination polymer. (Note 38) The process according to any one of the appendices 27 to 37, wherein the layered metal coordination polymer is decomposed in an organic solvent and reconstructed from the organic solvent by evaporation. (Note 39) The process described in Appendix 38, wherein the concentration of the metal coordination polymer decomposed in the organic solvent is preferably about 4 M to about 120 M. (Note 40) The process according to Appendix 38 or Appendix 39, wherein the evaporation of the organic solvent is carried out at a temperature of about -20°C to about 40°C and a vapor pressure of about 0.1 kPa to about 10 kPa. (Note 41) The process according to any one of the appendices 27 to 39, wherein the layered metal coordination polymer is peeled off to obtain one or more metal coordination polymer layers. (Note 42) The peeling off of the layered metal coordination polymer is the process of removing the metal coordination polymer scattered between each layer. Rayville By removing ions, each R of the organic linker in each metal-coordinate polymer layer 1 The process according to Appendix 41, comprising disrupting the electrostatic interaction between the one or more portions of the optionally interrupted alkyl group to obtain one or more metal-coordinate polymer layers. (Note 43) The process according to Appendix 41 or Appendix 42, wherein peeling off the layered metal coordination polymer includes dispersing and stirring the layered metal coordination polymer in water or an organic solvent to peel off the layered metal coordination polymer and obtain one or more metal coordination polymer layers. (Note 44) The process according to Appendix 43, wherein the layered metal coordination polymer is stirred at room temperature. (Note 45) The process according to Appendix 43 or 44, wherein the layered metal coordination polymer is stirred by ultrasonic treatment for a certain period of time effective in peeling off the layered metal coordination polymer to obtain one or more metal coordination polymer layers. (Note 46) The process according to Appendix 45, wherein the layered metal coordination polymer is stirred by ultrasonic treatment for a fixed period of time of approximately 1 minute to 72 hours or 1 minute to 20 minutes, and the layered metal coordination polymer is peeled off to obtain one or more metal coordination polymer layers. (Note 47) A method for forming nanostructures, To provide a layered metal coordination polymer comprising two or more layers, wherein each layer comprises a metal atom coordinated to one or more organic linkers in order to form the metal coordination polymer, and To remove at least a portion of the coordination organic linker and form the nanostructure. The method, including the method described above. (Note 48) The method according to Appendix 47, wherein removing at least a portion of the coordination organic linker to form the nanostructure comprises aging the layered metal coordination polymer. (Note 49) The method according to Appendix 48, wherein aging the layered metal coordination polymer includes heating the metal coordination polymer. (Note 50) The method according to Appendix 47 or Appendix 48, wherein removing at least a portion of the coordination organic linker to form the nanostructure comprises aging a solution containing the layered metal coordination polymer at a basic pH. (Note 51) The method according to Appendix 50, wherein the solution containing the layered metal coordination polymer is aged to a pH between approximately pH 7 and pH 10. (Note 52) The method according to Appendix 50 or Appendix 51, wherein the solution containing the layered metal coordination polymer is aged for a fixed period of about 1 minute to about 2 days. (Note 53) The method according to any one of the appendices 50 to 52, wherein the aging of the aforementioned solution is performed at a temperature of approximately 10°C to approximately 50°C. (Note 54) The method according to any one of the appendices 50 to 53, wherein at least a portion of the coordination organic linker is removed to exfoliate the layered metal coordination polymer before forming the nanostructure, thereby obtaining a dispersion of the metal coordination polymer layer. (Note 55) The method according to Appendix 54, wherein the step of peeling off the layered metal coordination polymer and removing at least a portion of the coordination organic linker to form an oxide nanostructure is performed simultaneously. (Note 56) The method according to Appendix 54 or 55, wherein the metal coordination polymer is dispersed in a solvent and stirred for a period of time effective in exfoliating the metal coordination polymer to obtain a dispersion of the metal coordination polymer layer before removing at least a portion of the coordination ligands, thereby forming the nanostructure. (Note 57) The method according to Appendix 56, wherein the metal coordination polymer is stirred by heating and / or ultrasonic treatment. (Note 58) The method according to any one of the appendices 50 to 57, wherein, before the formation of the nanostructure, at least a portion of the coordination ligand is removed, the metal coordination polymer is decomposed in an organic solvent and reconstructed from the organic solvent by evaporation, thereby changing the morphology of the metal coordination polymer. (Note 59) The method according to Appendix 58, wherein the concentration of the metal coordination polymer dissolved in the organic solvent is approximately 4 M to approximately 120 M. (Note 60) The method according to Appendix 58 or Appendix 59, wherein the evaporation of the organic solvent is carried out at a temperature of about -20°C to about 40°C and a vapor pressure of about 0.1 kPa to about 10 kPa. (Note 61) The method according to any one of the appendices 58 to 60, wherein the organic solvent is selected from alcohols, amines, or polar aprotic solvents. (Note 62) The method according to any one of the appendices 50 to 61, wherein the metal atom is a metal ion. (Note 63) The method according to Appendix 62, wherein the metal ion is monovalent or polyvalent. (Note 64) The method according to any one of the appendices 50 to 63, wherein the metal atom has an oxidation state that can increase when oxidized at an acidic pH. (Note 65) The method according to any one of the appendices 50 to 64, wherein removing at least a portion of the coordination organic linker destabilizes the metal atoms and sequentially forms stable nanostructures. (Note 66) The method according to any one of the appendices 50 to 65, wherein the morphology of the nanostructure is the same as the morphology of the metal-coordinate polymer. (Note 67) The method according to any one of the appendices 50 to 66, wherein the nanostructure is a porous oxide nanostructure, and the step of removing at least a portion of the coordination organic ligand is to form the porous nanostructure. (Note 68) The method according to any one of the appendices 50 to 67, wherein the nanostructure is polycrystalline. (Note 69) The method according to any one of the appendices 50 to 68, wherein one or more adsorbed species are adsorbed onto the surface of the nanostructure, and one or more heterojunctions are formed on the surface of the nanostructure. (Note 70) The method according to Appendix 69, wherein one or more species are adsorbed onto the surface of the nanostructure by removing at least a portion of the organic linker in the presence of the adsorbed species. (Appendix 71) The method according to Appendix 69 or Appendix 70, wherein the adsorbed species comprises one or more metal a...

Claims

1. A layered metal coordination polymer comprising two or more layers, Each layer contains metal atoms coordinated to an organic linker in order to form a metal-coordinate polymer layer; in the formula, the organic linker is defined by formula (1): X-R １ (1) Selected from one or more compounds having the structure, During the ceremony: X is a metallic bonding portion for coordinating with a metal atom, and the metallic bonding portion (X) is a head group selected from carboxylate, amine, hydroxyl, thiol, or nitrile; and R １ These are alkyl, alkenyl, or alkynyl groups substituted with one or more halogens that form the layered metal-coordinate polymer by forming a weak electrostatic interaction with an adjacent metal-coordinate polymer layer, selected from van der Waals forces or hydrogen bonds. The layered metal coordination polymer is a layered metal coordination polymer containing Rayville ions scattered between the layers of the metal coordination polymer.

2. The layered metal coordination polymer according to claim 1, wherein a plurality of Rayville ions scattered between the metal coordination polymer layers form the layered metal coordination polymer, and thus form the weak electrostatic interaction with one or more halogens of the organic linker in each metal coordination polymer layer.

3. The layered metal coordination polymer according to claim 2, wherein the weak electrostatic interaction between the Rayville ions scattered between the metal coordination polymer layers and the one or more halogens of the organic linker in each metal coordination polymer layer is substantially orthogonal to the coordination bond between the metal bonding portion (X) and the metal atom in the metal coordination polymer layer.

4. The layered metal coordination polymer according to any one of claims 1 to 3, wherein one or more halogens are selected from the group consisting of F, Cl, Br, and I.

5. The layered metal-coordinating polymer according to any one of claims 1 to 4, wherein the metal-bonding portion (X) is a monodentate ligand that forms a coordination bond with a metal atom to form the metal-coordinating polymer layer.

6. The layered metal coordination polymer according to any one of claims 1 to 5, wherein the organic linker is trifluoroacetic acid, trichloroacetic acid, tribromoacetic acid, or triiodoacetic acid.

7. The aforementioned metal atom is Ce ３＋ Ce ４＋ Ti ４＋ , Zr ４＋ or Zn ２＋ A layered metal coordination polymer according to any one of claims 1 to 6, wherein the metal ion is selected from the following.

8. The metal coordination polymer is Ce(TCA) ２ (OH) ２ ·2H ２ O, and is the layered metal coordination polymer according to any one of claims 1 to 7.

9. The layered metal coordination polymer according to claim 8, wherein the cerium metal coordination polymer is characterized by an X-ray powder diffraction (XRD) pattern including one or more major peaks located at approximately 7.2, 8.1, 10.9, 20.6, 22.0, 23.1, and 23.2° (2θ).

10. A process for preparing a layered metal coordination polymer according to any one of claims 1 to 9, The layered metal coordination polymer is formed by combining a metal atom source with the organic linker. Includes, The process comprising the step of combining the metal atom source and the organic linker, wherein the step of mixing an aqueous solution containing the metal atom source and the organic linker to form the layered metal coordination polymer.

11. The process according to claim 10, wherein the step of forming the layered metal coordination polymer includes electrodeposition.

12. The process according to claim 11, wherein the initial pH of the aqueous solution during electrodeposition is less than about 7.

13. The process according to claim 11 or 12, wherein the electrodeposition is carried out within the oxygen-evolving region of the aqueous solution containing the metal atom source and the organic linker.

14. The process according to any one of claims 10 to 13, wherein the layered metal coordination polymer is decomposed in an organic solvent, reconstructed by evaporation of the organic solvent, and the reconstruction from the organic solvent alters the morphology of the metal coordination polymer.

15. The process according to any one of claims 10 to 14, wherein the layered metal coordination polymer is peeled off to obtain one or more metal coordination polymer layers.

16. A method for forming nanostructures, To provide a layered metal coordination polymer according to any one of claims 1 to 9, and To remove at least a portion of the organic linker to form the nanostructure. The method, including the method described above.

17. The method according to claim 16, wherein at least a portion of the organic linker is removed to exfoliate the layered metal coordination polymer before forming the nanostructure, thereby obtaining a dispersion of the metal coordination polymer layer.

18. The method according to claim 16 or 17, wherein, before removing at least a portion of the organic linker to form the nanostructure, the metal coordination polymer is decomposed in an organic solvent and reconstructed from the organic solvent by evaporation.

19. A catalyst composition comprising a nanostructure prepared using the method described in any one of claims 16 to 18.

20. Use of a nanostructure prepared using the method described in any one of claims 16 to 19 as a catalyst.

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