A kind of fusion porphyrin axial modification Ti3C2T x Nonlinear optical nano-hybrid materials, their preparation and use

Abstract

The application relates to a kind of fusion porphyrin axial modification Ti3C2T x Nonlinear optical nanohybrid materials, their preparation and use, the nanohybrid materials are fused porphyrin by the zinc atom of ring center and covalently connected on the surface of Ti3C2T x The nitrogen atom on the pyridine ring on the surface of nanosheet forms a coordination bond. Compared with single functional components, the nanohybrid material TFP-Ti3C2T x Both nanosecond pulsed light at 532 nm and femtosecond pulsed light at 800 nm exhibit significantly enhanced optical limiting effect. The application develops a surface chemical modification strategy for titanium carbide MXene, and the obtained nanohybrid material exhibits optical limiting performance in cross-time domain and spectral domain, which has the potential to be applied to modern photonic or optoelectronic devices.

Description

Technical Field

[0001] This invention pertains to organic-inorganic functional composite materials and military-grade high-power laser protection materials, specifically a porphyrin-modified Ti3C2T composite material. x Nonlinear optical nanohybrid materials and their preparation and application. Background Technology

[0002] Nonlinear optical (NLO) materials have been widely applied in various fields, including electronic communications, all-optical data processing, optical switches, data storage, bioimaging, and quantum information technology. Nonlinear optical materials are currently a focus of scientific research. Over the past few decades, various types of nonlinear optical materials, such as semiconductors, organic molecules, inorganic glasses and crystals, and nanomaterials, have been extensively studied. Developing new materials with strong optical nonlinear properties and ultrafast response times has always been a research hotspot. Among them, two-dimensional materials such as graphene, transition metal sulfides, and black phosphorus nanosheets have attracted attention due to their excellent nonlinear optical properties. As an emerging two-dimensional material, MXenes have attracted great attention in optics, energy storage, and catalysis due to their high electrical conductivity, tunable bandgap, and ultrafast carrier dynamics. MXenes are prepared from transition metal carbides, nitrides, or carbonitrides with a MAX phase. Few-layer MXenes nanosheet structures can be obtained by etching the A layer with HF or HCl / LiF solution. The general formula for MXenes is M... n+1 X n T x In this model, M represents a transition metal element, such as titanium, molybdenum, and vanadium; X represents carbon, nitrogen, or a mixture of both; and T refers to the functional groups carried on its surface, such as -OH, =O, and -F. Recent studies have shown that MXenes have the potential to be high-performance nonlinear optical materials. The most widely studied example is Ti3C2T. x For example, Jiang et al. studied Ti3C2T x In the near-infrared region (800-1800 nm), it exhibits nonlinear optical properties, displaying a large nonlinear absorption coefficient of 10⁻¹³ eSu. Dong and colleagues prepared uniform two-dimensional Ti₃C₂T with variable thickness using interfacial film deposition technology. x The thin film exhibits thickness-dependent saturable absorption behavior at 1064 nm. With increasing film thickness, the saturation intensity decreases, while the modulation depth increases.

[0003] To further optimize and improve the Ti3C2T x Regarding the optical nonlinearity, researchers have proposed several feasible and effective research strategies. For example, Ti3C2T xNon-covalent modification, that is, some functional materials with nonlinear optical responses are modified with Ti3C2T through non-covalent interactions (van der Waals forces). x These components combine to form nanocomposites. Reports have shown that BP, Fe3O4 nanoparticles, and Ag nanoparticles can be successfully loaded onto Ti3C2T. x This leads to an enhancement of the overall nonlinear optical performance. Recently, Huang et al. reported on the electrochemical modulation of Ti3C2T... x The nonlinear optical response of Ti3C2T at different wavelengths. By applying different voltages, Ti3C2T x The functional groups on the surface can switch between -OH-rich and =O-rich, and the corresponding nonlinear optical properties (saturated absorption or antisaturated absorption) will also change accordingly. However, existing control methods inevitably have certain limitations. On the one hand, the binding force between the two non-covalently interacting components is weak, making it difficult to generate an efficient charge transfer process, and the van der Waals stacked complexes are also less stable during solution processing, and the structure is easily destroyed. On the other hand, the change in nonlinear optical properties caused by electrochemical treatment is actually a "dynamic change," that is, when the applied electric field disappears, the resulting nonlinear optical properties also disappear. Therefore, electrochemical control is not ideal for Ti3C2T. x In practical applications, this is disadvantageous. Conversely, covalent functionalization can form strong covalent bonds between the two components. This not only ensures efficient charge transfer at the tightly connected hybrid interface, but also results in a stable hybrid material structure that is not easily damaged by external forces, ensuring structural and performance stability and meeting the requirements of production and processing. Although Ti3C2T x Covalent modification of Ti3C2T in important fields such as field-effect transistors, smart sensors, and supercapacitors has been reported. This study explores covalent chemistry for Ti3C2T. x The photophysical properties and nonlinear optical properties of organic functional molecules have not yet been fully explored. Summary of the Invention

[0004] The purpose of this invention is to overcome the shortcomings of the existing technology and provide a fused porphyrin axially modified Ti3C2T x Nonlinear optical nanohybrid materials, their preparation and applications: The prepared organic-inorganic covalent nanohybrid materials simultaneously combine fused porphyrin and Ti3C2T x The electronic and chemical structural characteristics of nanosheets enhance the nonlinear optical absorption performance of the material and broaden its application range in nonlinear optics.

[0005] The objective of this invention can be achieved through the following technical solutions:

[0006] In a first aspect, the present invention provides a fusion of porphyrin-axially modified Ti3C2T x Nonlinear optical nanohybrids, consisting of fused porphyrins covalently linked to Ti3C2T via zinc atoms at the ring center. x The nanosheets are obtained by forming coordination bonds on nitrogen atoms in the pyridine rings on the surface of the nanosheets.

[0007] In a second aspect, the present invention also provides a fusion of porphyrin-axially modified Ti3C2T x A method for preparing nonlinear optical nanohybrid materials includes the following steps:

[0008] (1) Take a few layers of titanium carbide Ti3C2T x Nanosheets were dispersed in deionized water, and an aqueous solution of pyridine diazonium salt and potassium iodide were added under ice bath conditions. After reaction, the pyridine-covalently modified Ti3C2T was obtained by separation. x Nanosheets, designated Py-Ti3C2T x ;

[0009] (2) Take the obtained Py-Ti3C2T x Dispersed in DMF, then fused porphyrin TFP was added, and the mixture was heated under reflux to obtain axially modified Ti3C2T with fused porphyrin. x The nanosheets are the target product TFP-Ti3C2T x .

[0010] Furthermore, in step (1), the Ti3C2T x The mass ratio of nanosheets, pyridine diazonium salt and potassium iodide is 50 mg:(450-550) mg:(0.8-1.2) g, preferably 50 mg:500 mg:1 g.

[0011] Furthermore, in step (1), the pyridine diazonium salt aqueous solution is prepared by the following method:

[0012] Sodium nitrite and 4-aminopyridine were dissolved in water and hydrochloric acid, respectively, and the resulting aqueous solutions of sodium nitrite and hydrochloric acid of 4-aminopyridine were cooled to 0°C using an ice bath.

[0013] A sodium nitrite aqueous solution cooled to 0°C was added dropwise to a hydrochloric acid solution of 4-aminopyridine. The reaction yielded a pale yellow solution, which was the aqueous solution of pyridine diazonium salt.

[0014] Furthermore, the ratio of sodium nitrite to water added is (1.2–1.3) g: 7 mL;

[0015] The ratio of 4-aminopyridine to hydrochloric acid is (1.5-1.7) g: 5 mL, and the concentration of the hydrochloric acid is 4 mol / L.

[0016] The mass ratio of sodium nitrite to 4-aminopyridine is (1.2–1.3):(1.5–1.7).

[0017] Furthermore, in step (2), Py-Ti3C2T x The mass ratio of TFP to TFP is 1:3 to 5, preferably 1:4.

[0018] Furthermore, in step (2), the temperature of the heating reflux is 115-125°C, preferably 120°C.

[0019] Furthermore, in step (2), the heating reflux time is 18 to 30 hours, preferably 24 hours.

[0020] Furthermore, in step (2), the heating reflux is carried out under a nitrogen atmosphere.

[0021] In a third aspect, the present invention provides a fusion of porphyrin-axially modified Ti3C2T x Applications of nonlinear optical nanohybrids as nonlinear optical materials.

[0022] Compared with the prior art, the present invention has the following advantages:

[0023] I. This invention utilizes diazonium salts to treat Ti3C2T x The free radical addition reaction and the coordination between nitrogen and metal atoms were used to, for the first time, axially covalently modify Ti3C2T with fused porphyrin molecules. x Surface. This invention expands the surface chemistry of titanium carbide MXene and enriches the design and preparation strategies for binary nano-hybrid materials based on titanium carbide MXene.

[0024] II. The nano-hybrid material TFP-Ti3C2T prepared in this invention x The transverse surface plasmon resonance signal from the MXene component in its ultraviolet-visible-near-infrared absorption spectrum showed a significant shift, proving that there is a strong electronic interaction between the fused porphyrin molecule and the two-dimensional nanosheet.

[0025] III. TFP-Ti3C2T prepared by this invention x The nanohybrid materials exhibit significantly enhanced optical confinement effects compared to single-component TFPs and pure nanosheets under both 532 nm nanosecond excitation and 800 nm femtosecond excitation. TFP and Ti3C2T x The coupling between nanosheets plays a crucial role in enhancing the overall nonlinear optical properties of the material. This hybrid system design approach is beneficial for the future synthesis and preparation of more Ti3C2T. x The study of binary nonlinear optical functional materials based on this has reference value. Attached Figure Description

[0026] Figure 1 The TFP-Ti3C2T prepared in this invention x Preparation routes of nano-hybrid materials;

[0027] Figure 2 The TFP-Ti3C2T prepared in this invention x Nano-hybrid materials and their precursor materials, Ti3C2T x The infrared spectrum;

[0028] Figure 3 The TFP-Ti3C2T prepared in this invention x X-ray diffraction (XRD) patterns of nano-hybrid materials and their precursor materials;

[0029] Figure 4 The TFP-Ti3C2T prepared in this invention x X-ray photoelectron spectroscopy (XPS) of nano-hybrid materials;

[0030] Figure 5 The TFP-Ti3C2T prepared in this invention x Nano-hybrid materials and their precursor materials Ti3C2T x Scanning electron microscope (SEM) and transmission electron microscope (TEM) images;

[0031] Figure 6 The TFP-Ti3C2T prepared in this invention x Ultraviolet absorption spectra of nano-hybrid materials and precursor materials;

[0032] Figure 7 The TFP-Ti3C2T prepared in this invention x Z-scan spectra of nano-hybrid materials and precursor materials at 800 nm wavelength;

[0033] Figure 8 The TFP-Ti3C2T prepared in this invention x Z-scan spectra of nano-hybrid materials and precursor materials at a wavelength of 532 nm. Detailed Implementation

[0034] The present invention will now be described in detail with reference to the accompanying drawings and specific embodiments. These embodiments are based on the technical solution of the present invention and provide detailed implementation methods and specific operating procedures. However, the scope of protection of the present invention is not limited to the following embodiments.

[0035] The raw materials used in the following examples were all from reagent companies such as Exploration Platform, Anaiji, and Bailingwei. The synthesis method of fused porphyrin was referenced from the literature (Ostrowski, S., Grzyb, S. (2012). Direct β-amination reaction in porphyrin systems - a simple route to compounds containing two nitrogen substances at both β-positions of the same pyrrole unit. Tetrahedron Letters, 53(47), 6355-6357.).

[0036] Unless otherwise specified, all other raw materials or processing technologies are commercially available products or conventional processing technologies in the field.

[0037] Example 1:

[0038] Reference Figure 1 The process flow shown in this embodiment provides a Ti3C2T process incorporating porphyrin axial modification. x Preparation methods of nano-hybrid materials:

[0039] first step:

[0040] 1 g of Ti3AlC2 was added in multiple batches to a mixture containing 9 M HCl solution and 1 g of lithium fluoride in 20 mL, and the suspension was continuously stirred at 40 °C for 24 hours. The crude product was then washed with deionized water and centrifuged at 8000 rpm for 5 minutes. This process was repeated several times until the pH of the supernatant reached 6. Deionized water was added to the centrifuged precipitate and the mixture was sonicated for 1 hour. The resulting dispersion was then centrifuged at 3500 rpm for 45 minutes, and the supernatant was collected. Deionized water was added to the remaining precipitate, and the process was repeated 2–3 times. Finally, 350 mg of black Ti3C2T was obtained by freeze-drying the supernatant. x Nanosheets.

[0041] Step Two:

[0042] 1.23 g NaNO2 and 1.6 g 4-aminopyridine (4-AP) were dissolved in 7 mL H2O and 5 mL 4M HCl, respectively, and then the system was cooled to 0 °C in an ice bath. The above NaNO2 aqueous solution was added dropwise to the hydrochloric acid solution of 4-AP, and the resulting pale yellow solution (i.e., the pyridine diazonium salt aqueous solution) was maintained at 0 °C in an ice bath and stirred for 30 minutes.

[0043] Subsequently, 100 mg of Ti3C2T was taken. xNanosheets were dispersed in 100 mL of deionized water and ultrasonically dispersed until homogeneous. The dispersion was then added dropwise to an aqueous solution of pyridine diazonium salt while maintaining the temperature at 0 °C to prevent decomposition of the diazonium salt. After reacting at 0 °C for 3 hours, 1 g of potassium iodide was added, and the mixture was stirred at room temperature for another 15 hours. The reaction solution was filtered through a 0.22 μm pore size filter membrane. The resulting black solid was dispersed in DMF and subjected to multiple ultrasonic-filtration-redispersion processes to ensure complete removal of unreacted small organic molecules and other reaction byproducts. The mixture was then dried in a vacuum drying oven at 80 °C for 24 hours to obtain pyridine-modified Ti3C2T. x Nanosheets (Py-Ti3C2T) x ).

[0044] Step 3:

[0045] The reaction was carried out under a nitrogen atmosphere. 50 mg of Py-Ti3C2T was added. x The mixture was placed in a round-bottom flask equipped with a reflux condenser, and 50 mL of DMF was added, followed by sonication for 1 hour. Then, 200 mg of TFP was added to the reactants, and the reaction mixture was stirred at 120 °C for 24 hours. After the reaction was complete and cooled to room temperature, the reaction solution was filtered through a 0.22 μm pore size filter membrane. The filter cake was washed several times with organic solvents such as DMF, tetrahydrofuran, and dichloromethane until no absorption spectral signal of the fused porphyrin was detected in the final filtrate. The filter cake was then dried in a vacuum drying oven at 80 °C for 24 hours to obtain the final product (TFP-Ti3C2T). x ).

[0046] Figure 2 The prepared nano-hybrid material TFP-Ti3C2T x Infrared spectra of Ti3C2T and precursor materials. First, focus on Ti3C2T. x Samples located at 3601 and 1462 cm -1 The absorption peak at 1664 cm⁻¹ can be attributed to the stretching and bending vibration modes of the -OH group. -1 The absorption peak at 500 to 800 cm⁻¹ is attributed to C=O. -1 The wavelength range includes vibrational modes of Ti-OH, Ti-O, and Ti-C bonds. For Ti3C2T... x After the nanosheets were modified with diazonium salt, Py-Ti3C2T x The high wavenumber region of the sample's infrared spectrum shows a significant decrease in the peak intensity of the stretching vibration from -OH, indicating that a large amount of hydroxyl groups were consumed during the reaction with the pyridine diazonium salt. Meanwhile, in the 900-1600 cm⁻¹ region... -1 The new absorption peak observed within the range is caused by the stretching vibration of the pyridine ring (located at 992 cm⁻¹). -1The pyridine ring skeleton vibration at 1529 and 1594 cm -1 (CC stretching vibration at 2200-2300 cm). It is noteworthy that at 2200-2300 cm... -1 No N2 from diazonium salts was observed within the wavelength range. + The characteristic stretching vibration peaks of the pyridine group indicate that the pyridine group is covalently attached to Ti3C2T. x Surface rather than simple physical adsorption. For TFP samples, at 959 and 865 cm⁻¹ -1 The absorption peak at this point can be attributed to the NH stretching vibration peak on the porphyrin ring, while the stretching vibration peaks of pyrrole CN at the center of the porphyrin ring are located at 1096 and 1221 cm⁻¹, respectively. -1 The characteristic absorption peaks of the porphyrin molecule mentioned above are also located at TFP-Ti3C2T. x The presence of porphyrin in the infrared spectrum of the sample indicates that the fused porphyrin was successfully modified into Ti3C2T via axial coordination between the N atom on pyridine and the zinc atom. x surface.

[0047] Figure 3 The prepared nano-hybrid material TFP-Ti3C2T x X-ray diffraction patterns of Ti3AlC2 and Ti3C2T precursor materials. x For example, the diffraction peak at 39.2° belonging to the (104) crystal plane of the precursor Ti3AlC2 disappeared after etching, and the (002) diffraction peak shifted to a lower angle of 6.3°. These two points indicate that the Al atomic layer was completely removed and the Ti3C2T… x Generation of nanosheets. After diazonium salt modification, Py-Ti3C2T x The (002) diffraction peak shifted to 5.6°. For MXene-type materials, the change in the position of the (002) diffraction peak represents a change in the interlayer spacing, which is closely related to the interlayer inserts. Clearly, Py-Ti3C2T x The increased interlayer distance should be attributed to the introduction of pyridine molecules. For TFP-Ti3C2T x The (002) diffraction peak of the sample shifted further to a lower angle of 5.2°, indicating that the introduction of porphyrin molecules further expanded the diffraction range of Ti3C2T. x The interlayer spacing. It is worth noting that Py-Ti3C2T x and TFP-Ti3C2T x The (002) diffraction peak compared to the original Ti3C2T x The sample strength was reduced, which may be due to the surface functional groups covering and disrupting the Ti3C2T x This is due to the stacking structure of the layers along the c-axis.

[0048] Figure 4 The prepared nano-hybrid material TFP-Ti3C2T x The X-ray photoelectron spectra of the precursor materials and the precursor materials were examined. It can be seen that both materials exhibit five peaks centered at 684, 563, 530, 455, and 284 eV in their XPS spectra. These characteristic peaks are attributed to F1s, Ti2s, O1s, Ti2p, and C1s, respectively. Meanwhile, in Py-Ti3C2T… x A nitrogen signal was observed, indicating the successful introduction of the pyridine ring. Further investigation was conducted to determine the relationship between the pyridine molecule and Py-Ti3C2T. x Information on chemical bonds between them Figure 4 b and 4c respectively give Ti3C2T x and Py-Ti3C2T x The fine spectra of O1s were obtained. Both groups of samples exhibited characteristic peaks at approximately 531.4 and 529.8 eV, belonging to Ti-OH and Ti-O, respectively. Furthermore, Py-Ti3C2T... x A new peak appears at 531 eV, which can be attributed to porphyrin and Ti3C2T. x The newly formed Ti-OC bonds between the nanosheets further demonstrate that pyridine molecules are covalently linked to Ti3C2T. x The surface results are consistent with those obtained from infrared spectroscopy. Figure 4 d and 4e respectively give TFP-Ti3C2T x XPS full spectrum and fine spectrum of Zn2p. After introducing fused porphyrin, TFP-Ti3C2T... x Two additional areas with a ratio of 2:1 appear in the middle, which are respectively attributed to Zn 2p 1 / 2 and Zn 2p 3 / 2 The peak. Considering that the sole source of Zn is TFP, this indicates that the TFP component was successfully linked to Ti3C2T via the pyridine axial direction. x surface.

[0049] Figure 5 For the prepared TFP-Ti3C2T x Nano-hybrid materials and their precursor materials Ti3C2T x Scanning electron microscope and transmission electron microscope images. Figure 5 ac respectively gave Ti3C2T x Py-Ti3C2T x TFP-Ti3C2T x The SEM image shows the original Ti3C2T. xFurthermore, the functionalized materials are all irregularly shaped, ultrathin nanosheets a few micrometers in size. No significant morphological changes were observed before and after functionalization, indicating that the reaction process of Ti3C2T... x The structure of the nanosheets was not destroyed. To further explore the surface morphology details of the sample, Figure 5 df provides the Ti3C2T x Py-Ti3C2T x TFP-Ti3C2T x TEM image of the original Ti3C2T. x The nanosheets exhibited clean and relatively smooth surfaces, indicating that Ti3C2T was synthesized during the process. x The nanosheets did not exhibit significant oxidation behavior and possessed a few-layered, sheet-like structure. However, after surface modification, Py-Ti3C2T... x and TFP-Ti3C2T x The surface of the hybrid becomes significantly rougher, indicating that the introduced organic molecules interact with Ti3C2T. x The nanosheets interacted with each other. Furthermore, Figure 5 g provides TFP-Ti3C2T x Elemental distribution diagrams of nano-hybrid materials, except for Ti3C2T x In addition to the Ti, C, and O elements contained in the nanosheets themselves, N and Zn elements from porphyrin are also uniformly distributed on the surface of the hybrid material. This result allows for axial modification of Ti3C2T by porphyrin. x The surface provides supplementary evidence.

[0050] Figure 6 For the prepared TFP-Ti3C2T x UV absorption spectra of nano-hybrid materials and precursor materials. Pure Ti3C2T x Nanosheets exhibit broadband absorption characteristics from the ultraviolet to near-infrared region due to their near-zero bandgap band structure, and their broad absorption peak at 790 nm is a transverse surface plasmon (TSP) resonance peak. Fusion porphyrins showed characteristic absorption peaks of By (420 nm), Bx (576 nm), and Qx (1123 nm) in the near-ultraviolet, visible, and near-infrared regions, respectively. The two split B bands originate from the exciton coupling effect generated by the Coulomb interaction between the transition dipole moments. Simultaneously, the triple bond melting connection between monomeric porphyrins altered the electron distribution of the porphyrin ring, disrupting the degeneracy of the eg orbitals, thus leading to a significant enhancement and redshift of the Q band absorption. These belong to TFP and Ti3C2T, respectively. x The characteristic absorption peak also appeared in TFP-Ti3C2T xIn the nano-hybrid material, it was shown that the organic component TFP was successfully bonded to Ti3C2T via axial linkage. x Surface. Specifically, TFP-Ti3C2T x The middle part represents Ti3C2T x The absorption peak of the TSP mode showed a significant blue shift (785 nm), while the By absorption peak, representing TFP, also red-shifted to 423 nm. And Ti3C2T x The absorption peak in the TSP mode is closely related to the concentration of free carriers on its surface, i.e., when electrons are injected into Ti3C2T... x When nanosheets are used, an increase in surface electron density causes a blue shift in the TSP peak position; conversely, a decrease in surface electron density leads to a red shift in the TSP. Therefore, TFP-Ti3C2T x The blue shift in the peak position observed in the spectrum indicates that TFP modification increases the efficiency of Ti3C2T. x The electron density of TFP. Simultaneously, the red shift of the By absorption peak position of TFP indicates an increase in the degree of conjugation of the porphyrin molecule. These phenomena collectively explain the interaction between TFP and Ti3C2T. x There is a clear electron transfer process between them.

[0051] Figure 7 For the prepared TFP-Ti3C2T x Z-scan spectra of the nano-hybrid materials and precursor materials at 800 nm wavelength. The incident light pulse width was 34 fs, and the rereading frequency was 1 kHz. All three groups of samples were dispersed in DMF, and their transmittance at 800 nm was uniformly adjusted to 70%. Figure 7 ac provides TFP and Ti3C2T respectively x and TFP-Ti3C2T x Z-scan measurement results within the energy range of 50-130 nJ. With increasing input energy, all three groups of samples exhibited laser energy-dependent inverse saturation absorption changes, with the valley of the curve gradually deepening. min It gradually decreases. Specifically, in the incident light energy range of 50-130 nJ, the TFP's T min The values ​​were 0.97, 0.95, and 0.92, respectively, for Ti3C2T. x T min The values ​​are 0.98, 0.97, and 0.95, respectively. For TFP-Ti3C2T x Nano-hybrid materials exhibit superior performance compared to pristine TFP and Ti3C2T under different incident laser energies. x Smaller T min The values ​​were 0.94, 0.92, and 0.89, respectively. For a more intuitive comparison, Figure 7d. TFP and Ti3C2T were compared under the same incident light energy (130 nJ). x and TFP-Ti3C2T x The Z-scan results, from the data fitting of the Z-scan curve, yielded β, which has been included. Figure 7 In f, the β value of each sample was calculated to be 0.00542 cm GW. -1 (Ti3C2T x ), 0.00869cm GW -1 (TFP) and 0.0145cm GW -1 (TFP-Ti3C2T x It can be observed that under femtosecond pulse conditions, TFP-Ti3C2T x Nano-hybrid materials also exhibit the lowest T min The value (0.89) and the largest β value (0.0145 cm GW) -1 This indicates that, compared to the original sample, TFP-Ti3C2T x The nonlinear optical properties of nano-hybrid materials are significantly enhanced.

[0052] Figure 8 The prepared TPP-Ti3C2T x Z-scan spectra of nano-hybrid materials and precursor materials at a wavelength of 532 nm. Figure 8 ac provides TFP and Ti3C2T respectively x and TFP-Ti3C2T x Z-scan measurement results were obtained within the energy range of 50-105 μJ. Under incident laser excitation of different intensities, the Z-scan curves of all samples exhibited symmetrical trough shapes, indicating the occurrence of a typical anti-saturation absorption phenomenon, which improves the optical confinement of the material to the incident laser. Specifically, for TFP, the T at its focal point... min The values ​​are 0.87 for pulse energies of 50 μJ, 0.80 for 75 μJ, and 0.74 for 105 μJ. For Ti3C2T x Nanosheets, with their focal T min The values ​​are 0.86 for pulse energies of 50 μJ, 0.77 for 75 μJ, and 0.68 for 105 μJ, respectively. For TFP-Ti3C2T x Nano-hybrids, with their focal T min The values ​​are 0.77 for pulse energies of 50 μJ, 0.68 for 75 μJ, and 0.56 for 105 μJ, respectively. Figure 8 d. TFP and Ti3C2T were compared under the same incident light energy (105 μJ). x and TFP-Ti3C2T xThe Z-scan results, and the nonlinear absorption coefficient (β) obtained from the data fitting of the Z-scan curve, have been included. Figure 8 In f, the β value of each sample was calculated to be 51.66 cm GW. -1 (TFP), 69.66cm GW -1 (Ti3C2T x ) and 130.86cm GW -1 (TFP-Ti3C2T x ).from Figure 8 It can be clearly seen in e and 8f that TFP-Ti3C2T x Nano-hybrid materials have the smallest T min The value (0.56) and the largest β value (130.86 cm GW) -1 ).

[0053] The above results indicate that TFP modification can effectively improve Ti3C2T x The nonlinear optical response of nanosheets under nanosecond pulsed laser conditions. Based on the results of the Z-scan test above, TFP-Ti3C2T... x Nano-hybrid materials exhibit better third-order nonlinear properties and wide-band NLO characteristics, greatly expanding the application range of materials. This method provides new ideas for the future design and fabrication of more, more flexible, and better-performing nonlinear optical materials and devices.

[0054] The above description of the embodiments is provided to enable those skilled in the art to understand and use the invention. It will be apparent to those skilled in the art that various modifications can be made to these embodiments, and the general principles described herein can be applied to other embodiments without inventive effort. Therefore, the present invention is not limited to the above embodiments, and any improvements and modifications made by those skilled in the art based on the disclosure of the present invention without departing from the scope of the invention should be within the protection scope of the present invention.

Claims

1. A porphyrin-modified Ti3C2T x Nonlinear optical nanohybrid materials, characterized in that, It consists of fused porphyrins covalently linked to Ti3C2T via zinc atoms at the ring center. x It is obtained by forming coordination bonds between nitrogen atoms on the pyridine ring on the surface of the nanosheet; This nano-hybrid material was prepared by the following steps: (1) Take Ti3C2T x Nanosheets were dispersed in deionized water, and an aqueous solution of pyridine diazonium salt and potassium iodide were added under ice bath conditions. After reaction, the pyridine-covalently modified Ti3C2T was obtained by separation. x Nanosheets, designated Py-Ti3C2T x ; (2) Take the obtained Py-Ti3C2T x Dispersed in DMF, then fused porphyrin TFP was added, and the mixture was heated under reflux to obtain axially modified Ti3C2T with fused porphyrin. x The nanosheets are the target product TFP-Ti3C2T x ; 2. The axially modified Ti3C2T fused with porphyrin as described in claim 1 x The method for preparing nonlinear optical nanohybrid materials is characterized by, Includes the following steps: (1) Take Ti3C2T x Nanosheets were dispersed in deionized water, and an aqueous solution of pyridine diazonium salt and potassium iodide were added under ice bath conditions. After reaction, the pyridine-covalently modified Ti3C2T was obtained by separation. x Nanosheets, designated Py-Ti3C2T x ; (2) Take the obtained Py-Ti3C2T x Dispersed in DMF, then fused porphyrin TFP was added, and the mixture was heated under reflux to obtain axially modified Ti3C2T with fused porphyrin. x The nanosheets are the target product TFP-Ti3C2T x .

3. The fused porphyrin axially modified Ti3C2T according to claim 2 x The method for preparing nonlinear optical nanohybrid materials is characterized by, In step (1), the Ti3C2T x The mass ratio of nanosheets, pyridine diazonium salt, and potassium iodide is 50 mg: (450–550) mg: (0.8–1.2) g.

4. The fused porphyrin axially modified Ti3C2T according to claim 2 x The method for preparing nonlinear optical nanohybrid materials is characterized by, In step (1), the aqueous solution of the pyridine diazonium salt is prepared by the following method: Sodium nitrite and 4-aminopyridine were dissolved in water and hydrochloric acid, respectively, and the resulting aqueous solutions of sodium nitrite and hydrochloric acid of 4-aminopyridine were cooled to 0°C using an ice bath. A sodium nitrite aqueous solution cooled to 0°C was added dropwise to a hydrochloric acid solution of 4-aminopyridine. The reaction yielded a pale yellow solution, which was the aqueous solution of pyridine diazonium salt.

5. The fused porphyrin axially modified Ti3C2T according to claim 4 x The method for preparing nonlinear optical nanohybrid materials is characterized by, The ratio of sodium nitrite to water added is (1.2–1.3) g: 7 mL; The ratio of 4-aminopyridine to hydrochloric acid is (1.5-1.7) g: 5 mL, and the concentration of the hydrochloric acid is 4 mol / L. The mass ratio of sodium nitrite to 4-aminopyridine is (1.2–1.3):(1.5–1.7).

6. The fused porphyrin axially modified Ti3C2T according to claim 2 x The method for preparing nonlinear optical nanohybrid materials is characterized by, In step (2), Py-Ti3C2T x The mass ratio of TFP to TFP is 1:3 to 5.

7. The fused porphyrin axially modified Ti3C2T according to claim 2 x The method for preparing nonlinear optical nanohybrid materials is characterized by, In step (2), the temperature of the heating reflux is 115-125℃.

8. The fused porphyrin axially modified Ti3C2T according to claim 2 x The method for preparing nonlinear optical nanohybrid materials is characterized by, In step (2), the heating and reflux time is 18 to 30 hours.

9. The fused porphyrin axially modified Ti3C2T according to claim 2 x The method for preparing nonlinear optical nanohybrid materials is characterized by, In step (2), the heating reflux is carried out under a nitrogen atmosphere.

10. The axially modified Ti3C2T fused with porphyrin as described in claim 1 x Applications of nonlinear optical nanohybrids as nonlinear optical materials.

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