A metal oxide capable of conducting oxygen ions and its preparation method and application

Abstract

The present invention discloses a metal oxide that can conduct oxygen ions, and its preparation method and application. A preparation method of a metal oxide that can conduct oxygen ions comprises the following steps: spreading a metal oxide with a particle size of less than 500 nm on a carrier, controlling the spreading thickness to be less than 1 mm, and then sintering at high temperature; after sintering, rapidly quenching the high-temperature metal oxide; collecting the material after the metal oxide cools, dispersing it in a dispersion, and finally extracting and peeling it from the dispersion to obtain metal oxide nanosheets or metal oxide nanoclusters. The present invention achieves extraction and peeling of the metal oxide through a thermal strain mechanism to obtain metal oxide nanosheets or nanoclusters. The special microstructure of the nanomaterial enables the material to maintain a very high concentration of free oxygen vacancies, providing a rich carrier for the transmission of oxygen ions. The broken dangling bonds on the surface of the nanomaterial provide a fast channel for the conduction of oxygen ions.

Description

Technical Field

[0001] The present invention relates to the technical field of conductor materials, and in particular to a metal oxide capable of conducting oxygen ions, a preparation method thereof and an application thereof. Background Art

[0002] Metal oxides with oxygen ion conductivity (pure oxygen ion conductors and mixed conductors) have a wide range of applications in solid oxide batteries (SOBs), metal-air batteries (MEBs), gas separation, chemical sensors, and chemical catalytic conversion. For example, in SOBs, pure OBs serve as electrolyte materials, enabling efficient conversion between electrical and chemical energy through the targeted transport of oxygen ions. OBs with mixed OBs can significantly improve battery energy conversion efficiency by acting as catalysts for the oxygen electrode's oxygen reduction reaction (ORR) and oxygen evolution reaction (OER) processes. In MEBs, OBs with mixed OBs can serve as oxygen catalysts, enabling efficient chemical-to-electrical conversion. In gas separation and chemical sensors, these materials, based on their selective permeability to oxygen vacancies, provide a technological foundation for industrial-grade oxygen purification and high-precision environmental monitoring. In chemical catalytic conversion, OBs with oxygen ion conductivity can serve as carriers for metals such as Ru and Ni, promoting the synthesis and decomposition of fuels such as ammonia, methanol, and methane by optimizing reaction kinetics.

[0003] The conduction of oxygen ions in metal oxides originates from the long-range migration of oxygen ions through oxygen vacancies or interstitial sites in the crystal lattice. The development of metal oxide materials with high oxygen ion conductivity at low temperatures is an urgent need for technical performance improvement and technological innovation of solid oxide batteries, metal-air batteries, gas separators, chemical sensors and chemical catalytic conversion catalysts. For example, in order to reduce the production and operating costs of solid oxide batteries and improve market competitiveness, people are focusing on the development of solid oxide batteries that can operate at low temperatures. One of the core tasks is to develop metal oxide materials with good oxygen ion conductivity at low temperatures. Choi et al. prepared a cubic fluorite structure material Zr with oxygen ion conductivity. 0.92 Y 0.16 O 2.08 (YSZ), whose oxygen ion conductivity at 644℃ reaches 0.01S·cm -1Based on this material, people have prepared solid oxide batteries working in the range of 700-1000℃ (Oh Hyun Kwon, Gyeong Man Choi, "Electrical conductivity of thick film YSZ", Solid State Ionics. 2006, 177, 3057-3062.DOI:10.1016 / j.ssi.2006.07.039.); Huang et al. prepared the perovskite structure material La 0.8 Sr 0.2 Ga 0.83 Mg 0.17 O 2.815 (LSGM), making the metal oxide at 0.01S·cm -1 The working temperature was reduced to 534℃ (Keqin Huang, Robin S. Tichy, John B. Goodenough, "Superior perovskite oxide-ion conductor; Strontium- and magnesium-doped LaGaO3: I, Phase relationshipsand electrical properties", Journal of the American Ceramic Society. 1998, 81,2565-2575. DOI:10.1111 / j.1151-2916.1998.tb02662.x.); Yashima et al. designed and prepared a fluorite-like three-layer material Bi 1.9 Te 0.1 LuO 4.05 Cl, so that the metal oxide material at 0.01S·cm -1The conductivity of the material was reduced to 431 ° C (Nachi Ueno, Hiroshi Yaguchi, Kotaro Fujii, Masatomo Yashima, "High conductivity and diffusion mechanism of oxide ions in triple fluorite-like layers of oxyhalides", Journal of the American Chemical Society. 2024, 146, 11235–11244. DOI: 10.1021 / jacs.4c00265.). For the oxygen catalyst of solid oxide batteries, people have designed and developed a double perovskite structure metal oxide material LnBaCo2O with alternating A-site cations. 5+δ (Ln = lanthanide) and its derivatives provide a fast channel for oxygen ion conduction while ensuring high electronic conductivity, significantly improving the oxygen ion conduction rate (Albert Tarancón, Mónica Burriel, José Santiso, Stephen J. Skinnerc, John A.Kilner, "Advances in layered oxide cathodes for intermediate temperature solid oxide fuel cells", Journal of Materials Chemistry. 29, 20, 3799-3813. DOI:10.1039 / B922430K.).

[0004] Crystallographic knowledge shows that the conductivity of oxygen ions in metal oxides is closely related to their migration barrier and carrier concentration. At present, research on reducing the migration barrier of oxygen ions mainly focuses on the design of crystal structure and the regulation of chemical composition, hoping to reduce the migration barrier of oxygen ions through the above work. However, this work requires the coordination of crystal structure and chemical composition, the design is very difficult, and the controllable space is very limited. Free oxygen vacancies are the carriers of oxygen ion conduction in metal oxides. The concentration of oxygen vacancies in the material can be effectively increased by doping the material with heterovalent metal cations and cation vacancies. However, a large number of research works have confirmed that when the oxygen vacancies in metal oxides reach a certain concentration, they will spontaneously form ordered clusters, resulting in a decrease in the concentration of free oxygen vacancies, which limits the further improvement of oxygen ion conductivity. Summary of the Invention

[0005] In order to solve the above technical problems, the present invention provides a metal oxide capable of conducting oxygen ions, a preparation method thereof, and an application thereof.

[0006] The technical problem to be solved by the present invention is achieved through the following technical solutions:

[0007] In a first aspect, a metal oxide capable of conducting oxygen ions is provided, which is a metal oxide nanosheet or metal oxide nanoclusters obtained by sintering the metal oxide at a high temperature and then rapidly quenching the metal oxide to cause thermal strain and then peeling off.

[0008] Furthermore, the thickness of the metal oxide nanosheets is within 3 nm, preferably 0.2-3 nm; the sheet diameter is below 500 nm, preferably 2 nm-500 nm.

[0009] Furthermore, the metal oxide nanosheets are fluorite structures, and the components are Ce 1-x A x O 2-δ , wherein A is at least one of La, Pr, Nd, Sm and Gd, 0≤x≤0.5; or,

[0010] The metal oxide nanosheets are layered fluorite structures, and the components are Bi 2−x Te x LuO 4+x / 2 Cl, where 0≤x≤0.6; or

[0011] The metal oxide nanosheet has a perovskite structure and its components are ABO 3-δ , wherein A is at least one of Pr, Nd, Sm, Gd, Sr, Ba, and Ce, and B is at least one of Co, Mn, Mo, Bi, Ce, Ga, and Mg; or,

[0012] The metal oxide nanosheet has a double perovskite structure and its components are AA'B2O 5+δ , wherein A is at least one of Pr, Nd, Sm and Gd, A' is one or a combination of two of Ba and Sr, and B is one or more of Co, Mn, Cu and Mo.

[0013] It should be noted that the above δ represents a variable that changes with the oxygen content of the metal oxide as the valence state changes with temperature and chemical defect environment. Generally, 0≤δ≤1, but the present invention is not limited thereto.

[0014] Furthermore, the metal oxide nanoclusters are disordered cluster structures composed of several to thousands of atoms.

[0015] Furthermore, the metal oxide nanocluster component is Ce-AO, wherein A is at least one of La, Pr, Nd, Sm and Gd; wherein Ce accounts for 50%-100% of the molar content of the metal cations, and A accounts for 0%-50% of the molar content of the metal cations; or,

[0016] The metal oxide nanocluster component is Bi-Te-Lu-O-Cl, wherein Bi accounts for 5%-70% of the molar content of metal cations, Te accounts for 0%-10% of the molar content of metal cations, and Lu accounts for 30%-40% of the molar content of metal cations; or,

[0017] The metal oxide nanocluster component is ABO, wherein A is at least one of Pr, Nd, Sm, Gd, Sr, Ba and Ce, and B is at least one of Co, Mn, Mo, Bi, Ce, Ga and Mg; wherein A accounts for 40-60% of the molar content of the metal cations, and B accounts for 40-60% of the molar content of the metal cations; or,

[0018] The metal oxide nanocluster component is A-A'-B, wherein A is at least one of Pr, Nd, Sm and Gd, A' is one or a combination of two of Ba and Sr, and B is one or more of Co, Mn, Cu and Mo, wherein A accounts for 15-35% of the molar content of the metal cations, A' accounts for 15-35% of the molar content of the metal cations, and B accounts for 40-60% of the molar content of the metal cations.

[0019] In the second aspect, a method for preparing a metal oxide that can conduct oxygen ions includes the following steps: spreading a metal oxide with a particle size of less than 500 nm on a carrier, controlling the spreading thickness to be less than 1 mm, and then sintering at a high temperature; after sintering, rapidly quenching the metal oxide at a high temperature; collecting the material after the metal oxide is cooled, and dispersing it in a dispersion liquid, and finally extracting and peeling it from the dispersion liquid to obtain metal oxide nanosheets or metal oxide nanoclusters.

[0020] Furthermore, during sintering, the heating rate is 1-10°C / min, the sintering temperature is 1000-1500°C, and the holding time at the highest temperature point is 0.1-24h.

[0021] Furthermore, during the rapid quenching process, the time taken from taking out the high-temperature metal oxide to immersing it in the quenching liquid is ≤20s.

[0022] Furthermore, the quenching liquid used for quenching includes a cryogenic liquefied gas. In the present invention, the quenching liquid must meet the following characteristics: (1) It is gaseous at room temperature; (2) The quenching medium does not chemically react with the material during the quenching process; (3) The quenching medium does not contain any residues that contaminate the nanoclusters and nanosheets, nor does it generate new substances that contaminate the nanoclusters and nanosheets during contact with high-temperature particles; (4) The quenching medium can be easily separated from the nanoclusters and nanosheets without undergoing operations such as high-temperature sintering and centrifugal washing; (5) The quenching medium does not produce deflagration or splashing during contact with high-temperature metal oxide particles. Preferably, but not limited to, the cryogenic liquefied gas is at least one of liquid nitrogen, liquid helium, liquid argon, and liquid oxygen.

[0023] It should be noted that tiling refers to laying or scattering particles with a particle size of less than 500nm onto the surface of the carrier, and the thickness can be controlled to be less than 1mm. If the metal oxide is pressed into a block, large particles with a particle size of more than 500nm, or many particles are piled up above 1mm for quenching, the large particles or blocks will vaporize the surrounding low-temperature liquefied gas at high temperature, forming a vaporization layer between the metal oxide and the quenching medium, which hinders the rapid conduction of heat, making it difficult to form a large temperature gradient and thermal stress on the surface of the metal oxide particles, and thus making it impossible to effectively peel off the metal oxide surface. It is worth noting that the particle size of the metal oxide is required to be within 500nm. In principle, the smaller the particle size, the better, that is, there is no minimum particle size limit; the thickness of the tiling can be controlled to be less than 1mm, and there is no minimum thickness limit.

[0024] Furthermore, the separation method is selected from differential centrifugation, rate zonal centrifugation or natural sedimentation. Furthermore, the dispersion liquid includes but is not limited to deionized water, acetone, methanol, terpineol, ethanol and N-methylpyrrolidone and other dispersion media, preferably, anhydrous ethanol is preferred.

[0025] Furthermore, during the sintering process, the metal oxide is placed on a Pt sheet or in a Pt crucible. It should be noted that the Pt sheet or Pt crucible serves as a support for the metal oxide during sintering to prevent the metal oxide from reacting with the setter plate during the high-temperature sintering process. It should be noted that in addition to the Pt sheet or Pt crucible, other support materials that can prevent the metal oxide from reacting with the support plate can also be used to support the metal oxide.

[0026] Thirdly, any of the following applications of metal oxides that can conduct oxygen ions as conductor materials:

[0027] Application in the preparation of solid oxide battery electrolytes;

[0028] Application in the preparation of battery electrode materials;

[0029] Application in the preparation of oxygen electrode materials for metal-air batteries;

[0030] Application in the preparation of oxygen separation membranes;

[0031] Application in the preparation of electrode materials for chemical sensors;

[0032] Application in the preparation of support materials for catalytic conversion catalysts of chemicals.

[0033] Compared with the existing technology, the present invention has the following beneficial effects: the present invention realizes the extraction and stripping of metal oxides through a thermal strain mechanism to obtain metal oxide nanomaterials, nanosheet structures or nanocluster forms, wherein the metal oxide nanosheet is an ultra-thin two-dimensional structural material with a thickness of only a few atomic layers, and the crystal structure is severely distorted during the stripping process, and has an exceeding specific surface area, a large number of unsaturated bonds and abundant free oxygen vacancies; the metal oxide nanocluster cations are completely disordered structures without periodic regularity, have ultra-high specific surface area and unsaturated dangling bonds, and contain free oxygen vacancies several times that of the parent material; the metal oxide nanosheets or nanoclusters prepared by the present invention achieve a high specific surface area of ​​2.7S·cm at 400°C. -1 Excellent ionic conductivity. The unique microstructure of nanomaterials enables the material to maintain a very high concentration of free oxygen vacancies, providing a rich carrier for the transmission of oxygen ions. The broken dangling bonds on the surface of nanomaterials provide a fast channel for the conduction of oxygen ions. BRIEF DESCRIPTION OF THE DRAWINGS

[0034] Figure 1 is Ce in Example 1 0.5 Pr 0.25 Sm 0.25 O 2-δ High-resolution transmission electron microscopy image of the nanosheets;

[0035] Figure 2 Bi in Example 2 1.9 Te 0.1 Lu 4.05 Transmission electron microscopy image of Cl nanosheets;

[0036] Figure 3 Bi in Example 3 1.7 Te 0.3 Lu 4.15 Transmission electron microscopy image of Cl nanosheets;

[0037] Figure 4 This is a transmission electron micrograph of the Pr-Sr-Ga-Mg-O nanosheets in Example 4;

[0038] Figure 5The Pr-Sr-Ga-Mg-O nanosheets and YSZ, LSGM and Bi in Example 4 1.9 Te 0.1 Lu 4.05 Oxygen ion conductivity of Cl at different temperatures in air atmosphere;

[0039] Figure 6 is Pr in Example 5 0.5 Sr 0.5 CoO 3-δ Transmission electron microscopy image of nanosheets;

[0040] Figure 7 is GdBa in Example 6 0.5 Sr 0.5 Co2O 5+δ Transmission electron microscopy image of nanosheets;

[0041] Figure 8 The thermal strain in Example 7 achieves Ce 0.8 Gd 0.2 O 1.9 Schematic diagram of the extraction and stripping of surface Ce-Gd-O nanoclusters;

[0042] Figure 9 is a high-resolution transmission electron microscopy image of Ce-Gd-O nanoclusters in Example 7;

[0043] Figure 10 The in-situ Raman spectra of Ce-Gd-O nanoclusters at different temperatures in Example 7;

[0044] Figure 11 The Ce-Gd-O nanoclusters and YSZ, LSGM and Bi in Example 7 1.9 Te 0.1 Lu 4.05 Oxygen ion conductivity of Cl at different temperatures in air atmosphere;

[0045] Figure 12 This is a high-resolution transmission electron microscopy image of the Ce-La-Sm-Gd-O nanoclusters in Example 8;

[0046] Figure 13 Bi after quenching at 1100℃ in liquid nitrogen in Example 9 1.4 Te 0.6 LuO 4.3 High-resolution transmission electron microscopy image of Bi-Te-Lu-O-Cl nanoclusters adsorbed on the surface of Cl particles;

[0047] Figure 14 This is an atomic force microscope image of the Nd-Ba-Co-O nanosheet in Example 10;

[0048] Figure 15 The voltage-current-power density curves of the solid oxide battery prepared with Nd-Ba-Co-O nanoclusters as the oxygen electrode at different temperatures in Example 10;

[0049] Figure 16 The Gd after quenching in liquid helium at 1200°C in Example 11 0.5 Ba 0.25 Sr 0.25 Ce 0.5 Mn 0.5 O 3-δ Transmission electron microscopy image of Gd-Ba-Sr-Ce-Mn-O nanoclusters adsorbed on the particle surface;

[0050] Figure 17 The PrBaCo2O in Example 12 was quenched in liquid nitrogen at 1250°C. 5+δ Spherical aberration-corrected transmission electron microscopy image of Pr-Ba-Co-O nanoclusters adsorbed on the particle surface;

[0051] Figure 18 For the Pr-Ba-Co-O nanoclusters and PrBaCo2O in Example 12 5+δ Voltage-current-power curve of the cell with particles as solid oxide fuel cell electrode material;

[0052] Figure 19 Ce is the Ce when the quenching temperature is 950℃ in Comparative Example 1 0.5 Pr 0.25 Sm 0.25 O 2-δ High-resolution transmission electron microscopy images of particles;

[0053] Figure 20 (a)-(c) are the blank Pt sheet and Pr in comparative example 2, respectively. 0.5 Sr 0.5 CoO 3-δ The powder is spread on the Pt sheet, Pr 0.5 Sr 0.5 CoO 3-δ Actual picture of the powder after sintering at 1550℃ and quenching;

[0054] Figure 21 (a) and (b) are Ce in Comparative Example 3. 0.9 La 0.15 Sm 0.15 Gd 0.15 O 2-δ SEM images of the particles and transmission electron microscopy images of the particles after quenching at 1300℃;

[0055] Figure 22 Ce in Comparative Example 4 0.9La 0.15 Sm 0.15 Gd 0.15 O 2-δ Transmission electron microscopy image of particles after quenching at 1300°C;

[0056] Figure 23 For the preparation of Pr nanosheets in Comparative Example 5 0.5 Sr 0.5 CoO 3-δ (a) SEM image of the bulk and (b) transmission electron microscopy image of the crushed particles after quenching.

[0057] Figure 24 For Pr in Comparative Example 6 0.5 Ba 0.25 Ca 0.25 CoO 3-δ Transmission electron micrograph of particles after quenching in liquid nitrogen at 1200°C;

[0058] Figure 25 is La in Comparative Example 6 0.6 Sr 0.4 Co 0.2 Fe 0.8 O 3-δ Transmission electron micrograph of particles after quenching in liquid nitrogen at 1200°C;

[0059] Figure 26 is La in Comparative Example 6 0.5 Sr 0.5 CoO 3-δ Transmission electron micrograph of particles after quenching in liquid nitrogen at 1200°C;

[0060] Figure 27 For Pr in Comparative Example 6 0.5 Sr 0.5 Co 0.5 Ni 0.5 O 3-δ Transmission electron micrograph of particles after quenching in liquid nitrogen at 1200°C;

[0061] Figure 28 Bi after quenching in deionized water at 1100℃ in Comparative Example 7 1.4 Te 0.6 LuO 4.3 High-resolution transmission electron microscopy image of the Cl particle surface;

[0062] Figure 29 The Gd 0.5 Ba 0.25 Sr 0.25 Ce 0.5 Mn 0.5 O3-δ High-resolution transmission electron microscopy image of particles. DETAILED DESCRIPTION

[0063] Unless otherwise specified, the raw materials and equipment used in the present invention are commonly used in the art. Unless otherwise specified, the methods used in the present invention are conventional methods in the art. Unless otherwise specified, the meanings of terms in this specification are the same as those generally understood by those skilled in the art. In the event of any conflict, the definitions in this specification shall prevail.

[0064] All numerical values ​​or expressions used in the specification and claims relating to component amounts, process conditions, etc. should be understood to be modified by "about" in all cases. All ranges relating to the same component or property include endpoints, which can be independently combined. Since these ranges are continuous, they include every numerical value between the minimum and maximum values. It should also be understood that any numerical range cited in this application is intended to include all subranges within that range.

[0065] The present invention will be described in detail below with reference to the examples. The examples are only preferred embodiments of the present invention and are not intended to limit the present invention.

[0066] Example 1 Ce with fluorite structure 0.5 Pr 0.25 Sm 0.25 O 2-δ Nanosheets

[0067] This example shows that Ce with fluorite structure 0.5 Pr 0.25 Sm 0.25 O 2-δ Nanosheets, which are electrolyte materials for solid oxide batteries.

[0068] Ce with fluorite structure 0.5 Pr 0.25 Sm 0.25 O 2-δ The preparation method of the nanosheets specifically includes the following steps:

[0069] (1) Ce with particle size less than 300nm 0.5 Pr 0.25 Sm 0.25 O 2-δ Place the powder on the Pt sheet, and control the thickness of the powder on the Pt sheet to be less than 0.8mm. The purpose of using the Pt sheet is to prevent Ce from forming during the high temperature sintering process. 0.5 Pr 0.25 Sm 0.25 O 2-δ Reacts with the setter;

[0070] (2) Carrying Ce 0.5 Pr 0.25 Sm 0.25 O 2-δ The Pt sheet was placed in a high-temperature furnace and sintered at 1200°C with a heating rate of 5°C / min and a holding time of 2h at the highest temperature.

[0071] (3) After the insulation is completed, Ce at 1200℃ 0.5 Pr 0.25 Sm 0.25 O 2-δ Quickly drop into liquid nitrogen, and the time from taking it out from the high-temperature furnace to immersing it in liquid nitrogen should be controlled within 5s;

[0072] (4) After the metal oxide is cooled, the material is collected and dispersed in anhydrous ethanol;

[0073] (5) Ce was extracted and stripped from the anhydrous ethanol dispersion using differential centrifugation at a speed of 8000 rpm. 0.5 Pr 0.25 Sm 0.25 O 2-δ Nanosheets.

[0074] The Ce prepared in this example 0.5 Pr 0.25 Sm 0.25 O 2-δ Nanosheets such as Figure 1 As shown in Figure 2, the nanosheets have a diameter of 2-5 nm and an oxygen ion conductivity of up to 0.15 S·cm at 400 °C. -1 , indicating that the Ce prepared in this example 0.5 Pr 0.25 Sm 0.25 O 2-δ Nanosheets have excellent oxygen ion conductivity and are a potential electrolyte material for solid oxide batteries.

[0075] Example 2 Bi with layered fluorite structure 1.9 Te 0.1 Lu 4.05 Cl nanosheets

[0076] This example shows that Bi with a layered fluorite structure 1.9 Te 0.1 Lu 4.05 Cl nanosheets, which are used as support materials for chemical catalytic conversion catalysts.

[0077] Bi with layered fluorite structure 1.9 Te 0.1 Lu 4.05 The preparation method of Cl nanosheets specifically includes the following steps:

[0078] (1) Bi with a particle size of less than 500 nm 1.9 Te 0.1 Lu 4.05 Cl is placed in a Pt crucible, and the thickness of the powder in the Pt crucible is controlled to be less than 0.8 mm. The purpose of using a Pt crucible is to prevent Bi from being sintered during high temperature sintering. 1.9 Te 0.1 Lu 4.05 Cl reacts with the setter;

[0079] (2) will carry Bi 1.9 Te 0.1 Lu 4.05 The Cl-containing Pt crucible was placed in a high-temperature furnace and sintered at 1000°C with a heating rate of 1°C / min and a holding time of 10 h at the highest temperature.

[0080] (3) After the insulation is completed, Bi will be at 1000℃ 1.9 Te 0.1 Lu 4.05 Cl is quickly dropped into liquid helium, and the time from being taken out of the high-temperature furnace to being immersed in liquid helium is controlled within 3 seconds;

[0081] (4) After the metal oxide is cooled, the material is collected and dispersed in anhydrous ethanol;

[0082] (5) Bi was extracted and stripped from the anhydrous ethanol dispersion using rate zonal centrifugation 1.9 Te 0.1 Lu 4.05 Cl nanosheets.

[0083] Figure 2 The prepared Bi 1.9 Te 0.1 Lu 4.05 Transmission electron microscopy of Cl nanosheets. It can be seen from the figure that the diameter of the prepared nanosheets is ≤5nm, and Bi 1.9 Te 0.1 Lu 4.05 The electrical conductivity of Cl nanosheets at 400°C is as high as 2.4 S·cm -1 , is the corresponding parent material Bi 1.9 Te 0.1 Lu 4.05 The electrical conductivity of Cl at 400℃ (6.5×10 –3 S•cm -1 ) is 369 times. Using this material as a carrier, an appropriate amount of Bi 1.9 Te 0.1 Lu 4.05 Cl nanosheets were mixed with RuCl3 in deionized water to make Ru 3+ Adsorbed to Bi1.9 Te 0.1 Lu 4.05 Cl nanosheet surface; the Ru loaded 3+ Bi 1.9 Te 0.1 Lu 4.05 Cl nanosheets; loaded with Ru 3+ Bi 1.9 Te 0.1 Lu 4.05 The Cl nanosheets were placed in a nitrogen-hydrogen mixture (H2 10 vol%) and reduced at 500℃ for 2h to obtain Bi 1.9 Te 0.1 Lu 4.05 An ammonia decomposition catalyst with Cl nanosheets and Ru as active sites, wherein the Ru loading amount is 2 wt.%, was placed in an ammonia decomposition fixed bed at 1 atmosphere for catalytic performance testing. The test results are shown in Table 1, and the catalyst exhibits very high catalytic activity for ammonia decomposition.

[0084] Table 1 uses Bi 1.9 Te 0.1 Lu 4.05 Test results of ammonia decomposition rate of Ru-based catalyst supported by Cl nanosheets at different temperatures and space velocities at 1 atmosphere

[0085]

[0086] Example 3 Bi with layered fluorite structure 1.7 Te 0.3 Lu 4.15 Cl nanosheets

[0087] This example shows that Bi with a layered fluorite structure 1.7 Te 0.3 Lu 4.15 Cl nanosheets, which are used as support materials for chemical catalytic conversion catalysts.

[0088] Bi with layered fluorite structure 1.7 Te 0.3 Lu 4.15 The preparation method of Cl nanosheets specifically includes the following steps:

[0089] (1) Bi with a particle size of less than 100 nm 1.7 Te 0.3 Lu 4.15 Cl is placed in a Pt crucible, and the thickness of the powder in the Pt crucible is controlled to be less than 0.1 mm. The purpose of using a Pt crucible is to prevent Bi from being sintered during high temperature sintering. 1.7 Te 0.3 Lu 4.15Cl reacts with the setter;

[0090] (2) will carry Bi 1.7 Te 0.3 Lu 4.15 The Cl-containing Pt crucible was placed in a high-temperature furnace and sintered at 1200°C with a heating rate of 1°C / min and a holding time of 2 h at the highest temperature.

[0091] (3) After the insulation is completed, Bi will be at 1200℃ 1.7 Te 0.3 Lu 4.15 Cl was quickly dropped into liquid helium, and the time from being taken out of the high-temperature furnace to being immersed in liquid helium was controlled within 5s;

[0092] (4) After the metal oxide is cooled, the material is collected and dispersed in terpineol;

[0093] (5) Bi was extracted and stripped from the pineol dispersion using rate zonal centrifugation. 1.7 Te 0.3 Lu 4.15 Cl nanosheets.

[0094] Figure 3 The prepared Bi 1.7 Te 0.3 Lu 4.15 Transmission electron microscopy of Cl nanosheets. It can be seen from the figure that the diameter of the prepared nanosheets is ≤5nm, and Bi 1.7 Te 0.3 Lu 4.15 The oxygen ion conductivity of Cl nanosheets at 400℃ is as high as 1.8S·cm -1 It is a good carrier for the decomposition of natural gas, biogas, methanol, ethanol and ammonia to produce hydrogen.

[0095] Example 4 Pr-Sr-Ga-Mg-O Nanosheets with Perovskite Structure

[0096] This example shows Pr-Sr-Ga-Mg-O nanosheets with a perovskite structure, which are used as solid oxide battery electrolyte materials.

[0097] The preparation method of Pr-Sr-Ga-Mg-O nanosheets having a perovskite structure specifically comprises the following steps:

[0098] (1) Pr-Sr-Ga-Mg-O with a particle size of less than 400 nm is placed in a Pt crucible. The thickness of the powder in the Pt crucible is controlled to be less than 0.5 mm. The purpose of using a Pt crucible is to prevent the Pr-Sr-Ga-Mg-O from reacting with the setter during high-temperature sintering.

[0099] (2) Place the Pt crucible loaded with Pr-Sr-Ga-Mg-O in a high-temperature furnace and sinter at 1500°C with a heating rate of 5°C / min and a holding time of 2 h at the highest temperature;

[0100] (3) After the insulation is completed, the Pr-Sr-Ga-Mg-O at 1500°C is quickly dropped into liquid helium, and the time from taking it out of the high-temperature furnace to immersing it in liquid helium is controlled within 3 seconds;

[0101] (4) After the metal oxide is cooled, the material is collected and dispersed in deionized water;

[0102] (5) Pr-Sr-Ga-Mg-O nanosheets were extracted and exfoliated from deionized water dispersion using rate zonal centrifugation.

[0103] Figure 4 The transmission electron micrograph of the prepared Pr-Sr-Ga-Mg-O nanosheets is given. It can be seen from the figure that the diameter of the prepared nanosheets is ≤5nm. The local magnified image of the nanoparticles shows that the prepared nanosheets have a large amount of lattice distortion. Figure 5 The oxygen ion conductivity of the prepared Pr-Sr-Ga-Mg-O nanosheets at different temperatures can be seen from the figure. The oxygen ion conductivity of the Pr-Sr-Ga-Mg-O nanosheets can reach 0.01S·cm at only 273℃. -1 , has excellent oxygen ion conductivity and is a potential electrolyte material for solid oxide batteries.

[0104] Example 5 Pr with perovskite structure 0.5 Sr 0.5 CoO 3-δ Nanosheets

[0105] This example shows that Pr with a perovskite structure 0.5 Sr 0.5 CoO 3-δ Nanosheets, which are used as electrode materials for oxygen separation membranes or chemical sensors.

[0106] Pr with perovskite structure 0.5 Sr 0.5 CoO 3-δ The preparation method of the nanosheets specifically includes the following steps:

[0107] (1) Pr with a particle size of less than 300nm 0.5 Sr 0.5 CoO 3-δ Place the powder in a Pt crucible, and control the thickness of the powder in the Pt crucible to be less than 0.05mm. The purpose of using a Pt crucible is to prevent Pr 0.5 Sr0.5 CoO 3-δ Reacts with the setter;

[0108] (2) Carrying Pr 0.5 Sr 0.5 CoO 3-δ The Pt crucible was placed in a high-temperature furnace and sintered at 1200 °C with a heating rate of 5 °C / min and a holding time of 2 h at the highest temperature.

[0109] (3) After the insulation is completed, the Pr 0.5 Sr 0.5 CoO 3-δ Quickly throw it into liquid oxygen, and the time from taking it out from the high-temperature furnace to immersing it in liquid oxygen should be controlled within 5 seconds;

[0110] (4) After the metal oxide is cooled, the material is collected and dispersed in acetone;

[0111] (5) Pr was extracted and stripped from the acetone dispersion using rate zonal centrifugation. 0.5 Sr 0.5 CoO 3-δ Nanosheets.

[0112] Figure 6 The prepared Pr 0.5 Sr 0.5 CoO 3-δ Transmission electron microscopy of nanosheets. It can be seen from the figure that the diameter of the prepared nanosheets is ≤5nm. 0.5 Sr 0.5 CoO 3-δ The oxygen ion conductivity of the nanosheets at 400°C is as high as 1.5 S·cm -1 The oxygen ion conductivity of its parent material at 400℃ is only 2.1×10 -4 S•cm -1 , so Pr 0.5 Sr 0.5 CoO 3-δ Nanosheets can be used as a nanomaterial with both oxygen ion and electron conductivity properties.

[0113] Example 6 GdBa with double perovskite structure 0.5 Sr 0.5 Co2O 5+δ Nanosheets

[0114] This embodiment shows that GdBa has a double perovskite structure 0.5 Sr 0.5 Co2O 5+δ Nanosheets for use as oxygen electrode materials in metal-air batteries.

[0115] GdBa with double perovskite structure 0.5 Sr 0.5 Co2O 5+δ The preparation method of the nanosheets specifically includes the following steps:

[0116] (1) GdBa with a particle size of less than 400nm 0.5 Sr 0.5 Co2O 5+δ Place the powder on a Pt crucible, and control the thickness of the powder in the Pt crucible to be less than 0.5 mm. The purpose of using a Pt crucible is to prevent GdBa from forming during high-temperature sintering. 0.5 Sr 0.5 Co2O 5+δ Reacts with the setter;

[0117] (2) will carry GdBa 0.5 Sr 0.5 Co2O 5+δ The Pt crucible was placed in a high-temperature furnace and sintered at 1200 °C with a heating rate of 5 °C / min and a holding time of 2 h at the highest temperature.

[0118] (3) After the insulation is completed, the GdBa will be at 1200℃ 0.5 Sr 0.5 Co2O 5+δ Quickly drop into liquid nitrogen and liquid helium, and the time from taking out from the high-temperature furnace to immersing in liquid nitrogen and liquid helium should be controlled within 20s;

[0119] (4) After the metal oxide is cooled, the material is collected and dispersed in anhydrous ethanol;

[0120] (5) GdBa was extracted and stripped from anhydrous ethanol dispersion using the natural sedimentation method. 0.5 Sr 0.5 Co2O 5+δ Nanosheets.

[0121] Prepared GdBa 0.5 Sr 0.5 Co2O 5+δ Nanosheet morphology Figure 7 As shown, its diameter is as high as 16nm and its oxygen ion conductivity at 400℃ is as high as 1.2S·cm -1 As a high oxygen ion and electron conductivity material, GdBa 0.5 Sr 0.5 Co2O 5+δ Nanosheets are a potential oxygen electrode material for metal-air batteries.

[0122] Example 7 Ce-Gd-O nanoclusters

[0123] This example shows Ce-Gd-O nanoclusters, which are used as electrolyte materials for solid oxide batteries.

[0124] The preparation method of Ce-Gd-O nanoclusters specifically includes the following steps:

[0125] (1) Ce with particle size less than 300nm 0.9 Gd 0.1 O 1.95 Place the powder on the Pt sheet, and control the thickness of the powder on the Pt sheet to be less than 1mm. The purpose of using the Pt sheet is to prevent Ce from forming during the high temperature sintering process. 0.9 Gd 0.1 O 1.95 Reacts with the setter;

[0126] (2) Carrying Ce 0.9 Gd 0.1 O 1.95 The Pt sheet was placed in a high-temperature furnace and sintered at 1300°C with a heating rate of 5°C / min and a holding time of 24h at the highest temperature.

[0127] (3) After the insulation is completed, Ce at 1300℃ 0.9 Gd 0.1 O 1.95 Quickly drop into liquid nitrogen, and the time from taking it out from the high-temperature furnace to immersing it in liquid nitrogen should be controlled within 1s;

[0128] (4) After the metal oxide is cooled, the material is collected and dispersed in anhydrous ethanol;

[0129] (5) Ce-Gd-O nanoclusters were extracted and exfoliated from anhydrous ethanol dispersion at a speed of 8000 rpm using differential centrifugation.

[0130] In this embodiment, Ce 0.9 Gd 0.1 O 1.95 The principle of surface exfoliation of Ce-Gd-O nanoclusters is as follows Figure 8 As shown, the fluorite structure metal oxide Ce at 1300℃ 0.9 Gd 0.1 O 1.95 During the rapid immersion in liquid nitrogen (~-200℃), the surface lattice shrinks due to the rapid cooling, and there is a significant thermal strain between it and the parent material. This thermal strain may cause Ce 0.9 Gd 0.1 O 1.95 The surface chemical bonds are broken, forming Ce-Gd-O nanoclusters rich in lattice distortion. Figure 9The high-resolution transmission electron microscopy image of the prepared Ce-Gd-O nanoclusters is given. It can be seen from the image that Ce-Gd-O forms disordered structure nanoclusters composed of several atoms. Figure 10 The in situ Raman spectra of Ce-Gd-O nanosheets in the temperature range of 50-600℃ are given. -1 The Raman spectrum of the Ce-Gd-O nanoclusters is related to the degree of disorder in the material. As can be seen from the figure, the Ce-Gd-O nanoclusters have a very obvious Raman peak in this region, indicating that the thermal strain exfoliation process will introduce significant disorder into the material. In addition, the Raman spectrum shows a Raman peak closely related to free oxygen vacancies, indicating that a large number of free oxygen vacancies exist in the prepared Ce-Gd-O nanoclusters. Figure 11 is the oxygen ion conductivity of the prepared Ce-Gd-O nanoclusters at different temperatures. It can be seen from the figure that the oxygen ion conductivity of Ce-Gd-O nanoclusters can reach 0.01S•cm at only 280℃ -1 , common oxygen ion conductor materials YSZ, LSGM and Bi 1.9 Te 0.1 Lu 4.05 The temperatures at which Cl reaches the corresponding conductivity values ​​are as high as 644°C, 534°C, and 431°C, respectively. This indicates that the Ce-Gd-O nanoclusters prepared in this example have excellent oxygen ion conductivity and are a potential electrolyte material for solid oxide batteries.

[0131] Example 8 Ce-La-Sm-Gd-O Nanoclusters

[0132] This example shows that Ce-La-Sm-Gd-O nanoclusters are good supports for hydrogen production from the decomposition of natural gas, biogas, methanol, ethanol, ammonia, diesel, gasoline, and kerosene.

[0133] The preparation method of Ce-La-Sm-Gd-O nanoclusters specifically includes the following steps:

[0134] (1) Ce with particle size less than 300nm 0.9 La 0.15 Sm 0.15 Gd 0.15 O 2-δ Place the powder on the Pt sheet, and control the thickness of the powder on the Pt sheet to be less than 1mm. The purpose of using the Pt sheet is to prevent Ce from forming during the high temperature sintering process. 0.9 La 0.15 Sm 0.15 Gd 0.15 O 2-δ Reacts with the setter;

[0135] (2) Carrying Ce 0.9 La0.15 Sm 0.15 Gd 0.15 O 2-δ The Pt sheet was placed in a high-temperature furnace and sintered at 1300°C with a heating rate of 5°C / min and a holding time of 20h at the highest temperature.

[0136] (3) After the insulation is completed, Ce at 1300℃ 0.9 La 0.15 Sm 0.15 Gd 0.15 O 2-δ Quickly drop into liquid nitrogen, and the time from taking it out from the high-temperature furnace to immersing it in liquid nitrogen should be controlled within 5s;

[0137] (4) After the metal oxide is cooled, the material is collected and dispersed in anhydrous ethanol;

[0138] (5) Ce-La-Sm-Gd-O nanoclusters were extracted and exfoliated from anhydrous ethanol dispersion at a speed of 8000 rpm using differential centrifugation.

[0139] like Figure 12 As shown, the fluorite structure metal oxide Ce at 1300℃ 0.9 La 0.15 Sm 0.15 Gd 0.15 O 2-δ During the rapid immersion in liquid nitrogen (~-200℃), the surface lattice shrinks due to the rapid cooling, and there is a significant thermal strain between it and the parent material. This thermal strain may cause Ce 0.9 La 0.15 Sm 0.15 Gd 0.15 O 2-δ The surface chemical bonds are broken, forming Ce-La-Sm-Gd-O nanoclusters composed of thousands of atoms, whose oxygen ion conductivity at 400°C is as high as 2.5S·cm -1 .

[0140] Example 9 Bi-Te-Lu-O-Cl nanoclusters

[0141] This example shows Bi-Te-Lu-O-Cl nanoclusters used as support materials for chemical catalytic conversion catalysts.

[0142] The preparation method of Bi-Te-Lu-O-Cl nanoclusters specifically includes the following steps:

[0143] (1) Bi with a particle size of less than 400 nm 1.4 Te 0.6 LuO 4.3Cl is placed in a Pt crucible, and the thickness of the powder in the Pt crucible is controlled to be less than 1 mm. The purpose of using a Pt crucible is to prevent Bi from being sintered during high temperature sintering. 1.4 Te 0.6 LuO 4.3 Cl reacts with the setter;

[0144] (2) will carry Bi 1.4 Te 0.6 LuO 4.3 The Cl-containing Pt crucible was placed in a high-temperature furnace and sintered at 1100°C with a heating rate of 10°C / min and a holding time of 4 h at the highest temperature.

[0145] (3) After the insulation is completed, Bi will be at 1100℃ 1.4 Te 0.6 LuO 4.3 Cl was quickly dropped into liquid argon, and the time from being taken out of the high-temperature furnace to being immersed in liquid argon was controlled within 4 seconds;

[0146] (4) After the metal oxide is cooled, the material is collected and dispersed in methanol;

[0147] (5) Bi-Te-Lu-O-Cl clusters were extracted and exfoliated from the methanol dispersion using rate zonal centrifugation.

[0148] In order to better observe the nanoclusters, the quenched Bi was collected from the dispersion in step (4) using a copper mesh. 1.4 Te 0.6 LuO 4.3 The oxygen ion conductivity of Bi-Te-Lu-O-Cl nanoclusters at 400℃ is as high as 2.3S·cm -1 , its parent material Bi 1.4 Te 0.6 LuO 4.3 The oxygen ion conductivity of Cl at 400℃ is only 6.1×10 -3 S•cm -1 .like Figure 13 As shown, after liquid nitrogen quenching, Bi 1.4 Te 0.6 LuO 4.3 An amorphous coating with a thickness of about 4 nm appears on the surface of Cl, which can be attributed to the formation of Bi-Te-Lu-O-Cl nanoclusters consisting of tens to thousands of atoms during the rapid quenching process.

[0149] Example 10 Nd-Ba-Co-O nanoclusters

[0150] This embodiment shows that Nd-Ba-Co-O nanoclusters are prepared using double perovskite structure materials, which are used as solid oxide battery electrode materials.

[0151] The preparation method of Nd-Ba-Co-O nanoclusters specifically includes the following steps:

[0152] (1) NdBaCo2O with a particle size of less than 500 nm 5+δ Place the powder on the Pt sheet, and control the thickness of the powder on the Pt sheet to be less than 1mm. The purpose of using the Pt sheet is to prevent NdBaCo2O from being sintered during high temperature sintering. 5+δ Reacts with the setter;

[0153] (2) NdBaCo2O 5+δ The Pt sheet was placed in a high-temperature furnace and sintered at 1200°C with a heating rate of 5°C / min and a holding time of 0.1h at the highest temperature.

[0154] (3) After the insulation is completed, NdBaCo2O at 1200℃ 5+δ Quickly drop into liquid helium, and the time from taking out from the high-temperature furnace to immersing in liquid helium should be controlled within 3s;

[0155] (4) After the metal oxide is cooled, the material is collected and dispersed in anhydrous ethanol;

[0156] (5) Nd-Ba-Co-O nanoclusters were extracted and exfoliated from anhydrous ethanol dispersion using the natural sedimentation method.

[0157] The morphology of the prepared Nd-Ba-Co-O nanoclusters is shown in Figure 14 As shown. The oxygen ion conductivity of Nd-Ba-Co-O nanoclusters at 400℃ is as high as 1.3S·cm -1 , its parent material is NdBaCo2O 5+δ The oxygen ion conductivity at 400℃ is only 1.1×10 - 4 S•cm -1 A single cell was assembled using this material as the oxygen electrode of a solid oxide battery, with hydrogen as fuel and vacancies as oxidants, and its performance was tested in the range of 650-800℃. Figure 15 As shown in Figure 2, the Nd-Ba-Co-O nanoclusters have excellent catalytic activity for oxygen reduction reaction, and the output power densities of the corresponding batteries at 650, 700, 750, and 800 °C are as high as 0.41, 0.70, 1.08, and 1.53 W·cm, respectively. -2 .

[0158] Example 11 Gd-Ba-Sr-Ce-Mn-O nanoclusters

[0159] This embodiment shows the use of perovskite structural material Gd 0.5 Ba 0.25 Sr 0.25 Ce 0.5 Mn 0.5 O 3-δ Preparation of metal oxide Gd-Ba-Sr-Ce-Mn-O nanoclusters for chemical sensor electrode materials.

[0160] The preparation method of Gd-Ba-Sr-Ce-Mn-O nanoclusters specifically includes the following steps:

[0161] (1) Gd with a particle size of less than 400 nm 0.5 Ba 0.25 Sr 0.25 Ce 0.5 Mn 0.5 O 3-δ Place on the Pt sheet, the thickness of the powder in the Pt sheet is controlled to be less than 0.8mm. The purpose of using the Pt sheet is to prevent Gd from being sintered during high temperature sintering. 0.5 Ba 0.25 Sr 0.25 Ce 0.5 Mn 0.5 O 3-δ Reacts with the setter;

[0162] (2) Carrying Gd 0.5 Ba 0.25 Sr 0.25 Ce 0.5 Mn 0.5 O 3-δ The Pt sheet was placed in a high-temperature furnace and sintered at 1200°C with a heating rate of 5°C / min and a holding time of 8h at the highest temperature.

[0163] (3) After the insulation is completed, the Gd 0.5 Ba 0.25 Sr 0.25 Ce 0.5 Mn 0.5 O 3-δ Quickly drop into liquid nitrogen, and the time from taking it out from the high-temperature furnace to immersing it in liquid nitrogen should be controlled within 8 seconds;

[0164] (4) After the metal oxide is cooled, the material is collected and dispersed in N-methylpyrrolidone;

[0165] (5) Gd-Ba-Sr-Ce-Mn-O nanoclusters were extracted and exfoliated from N-methylpyrrolidone dispersion using the natural sedimentation method.

[0166] In order to observe the existence of nanoclusters, a small amount of particles were taken from the anhydrous ethanol suspension in step (4) and observed by transmission electron microscopy. Figure 16 As shown, in Gd 0.5 Ba 0.25 Sr 0.25 Ce 0.5 Mn 0.5 O 3-δ A uniform coating of nanoclusters with a thickness of about 20 nm was observed on the particle surface. As mentioned above, this uniform coating can be attributed to the fact that the nanoclusters formed during the quenching process have a very high specific surface area and a very high surface energy, and the surface energy is reduced by forming a uniform coating on the surface of the parent particles. 0.5 Ba 0.25 Sr 0.25 Ce 0.5 Mn 0.5 O 3-δ The Gd-Ba-Sr-Ce-Mn-O nanoclusters have the characteristics of electron-oxygen ion mixed conductors. The oxygen ion conductivity at 400℃ is as high as 2.7S·cm -1 , its parent material Gd 0.5 Ba 0.25 Sr 0.25 Ce 0.5 Mn 0.5 O 3-δ The oxygen ion conductivity at 400℃ is only 1.3×10 -5 S•cm -1 The prepared Gd-Ba-Sr-Ce-Mn-O nanoclusters are expected to have broad application prospects in the fields of solid oxide battery electrode materials and chemical sensor electrode materials.

[0167] Example 12 Pr-Ba-Co-O nanoclusters

[0168] This embodiment shows the use of double perovskite structure material PrBaCo2O 5+δ Preparation of metal oxide Pr-Ba-Co-O nanoclusters for solid oxide fuel cell electrode materials.

[0169] The preparation method of Pr-Ba-Co-O nanoclusters specifically includes the following steps:

[0170] (1) PrBaCo2O with a particle size of less than 500 nm 5+δ The powder is placed on a Pt crucible, and the thickness of the powder in the Pt crucible is controlled to be less than 0.8 mm. The purpose of using a Pt crucible is to prevent PrBaCo2O from being sintered during high temperature sintering. 5+δ Reacts with the setter;

[0171] (2) PrBaCo2O 5+δ The Pt crucible was placed in a high-temperature furnace and sintered at 1250°C with a heating rate of 10°C / min and a holding time of 7h at the highest temperature.

[0172] (3) After the insulation is completed, PrBaCo2O 5+δ Quickly drop into liquid nitrogen, and the time from taking it out from the high-temperature furnace to immersing it in liquid nitrogen should be controlled within 5s;

[0173] (4) After the metal oxide is cooled, the material is collected and dispersed in anhydrous ethanol;

[0174] (5) Pr-Ba-Co-O nanoclusters were extracted and exfoliated from anhydrous ethanol dispersion using the natural sedimentation method.

[0175] In order to observe the existence of nanoclusters, a small amount of particles were taken from the dispersion in step (4) and observed by transmission electron microscopy. Figure 17 As shown in Figure 2, disordered Pr-Ba-Co-O nanoclusters were observed on the surface of highly crystalline nanoparticles. This indicates that Pr-Ba-Co-O nanoclusters can be obtained in this embodiment. The oxygen ion conductivity of Pr-Ba-Co-O nanoclusters at 400°C is as high as 2.1S·cm -1 , parent material PrBaCo2O 5+δ The oxygen ion conductivity at 400℃ is 1.2×10 -4 S•cm -1 In order to illustrate the excellent performance of Pr-Ba-Co-O nanoclusters as solid oxide fuel cell electrode materials, Pr-Ba-Co-O nanoclusters and PrBaCo2O 5+δ The material was used as the electrode material for solid oxide fuel cells to prepare anode-supported full cells. It is worth noting that except for the difference in electrode materials, the other components, production and testing methods of the two cells are the same. The electrochemical performance of the two cells tested at 750℃ and 800℃ is as follows Figure 18 As shown in Figure 2, the full cell using Pr-Ba-Co-O nanoclusters achieves an output power density of up to 1.79 W·cm at 750°C and 800°C, respectively. -2 and 2.65W•cm -2 , is PrBaCo2O 5+δ The material has a value of about 2.5 times the corresponding value, which highlights the advanced electrochemical performance of the nanocluster material disclosed in the present invention.

[0176] Comparative Example 1

[0177] The difference between this comparative example and Example 1 is that the sintering temperature is set to 950°C.

[0178] The transmission electron microscope image of the material after quenching in this comparative example is as follows Figure 19 As shown, only a small amount of nanosheets can be obtained, indicating that the sintering temperature is a very critical parameter in the material preparation process. If the sintering temperature is low, the temperature gradient on the surface of the metal oxide particles during the quenching process is relatively low, and the thermal strain formed is also relatively small, so only a very small number of nanosheets can be peeled off.

[0179] Comparative Example 2

[0180] The difference between this comparative example and Example 5 is that the sintering temperature is set to 1550°C. Figure 20 As shown in (a)-(c), due to the Pr 0.5 Sr 0.5 CoO 3-δ The powder has begun to melt, and the particles have merged with each other to form larger particles. In addition, Pr 0.5 Sr 0.5 CoO 3-δ The powder will also adhere to the surface of the Pt sheet. During the quenching process, although the temperature gradient on the material surface can theoretically be increased, the crystal structure of the material has been destroyed and the lattice thermal strain cannot be well formed. Therefore, no nanosheets and nanoclusters can be collected during the experiment.

[0181] Comparative Example 3

[0182] The difference between this comparative example and Example 8 is that: Ce with a particle size of less than 300 nm 0.9 La 0.15 Sm 0.15 Gd 0.15 O 2-δ Replaced with Ce with diameter between 0.5-2μm 0.9 La 0.15 Sm 0.15 Gd 0.15 O 2-δ Particles ( Figure 21 (a)).

[0183] The transmission electron microscopy of the particles after quenching in this comparative example is as follows Figure 21 As shown in (b), no nanosheets or nanoclusters were observed on the surface of the particles or in the blank area. 0.9 La 0.15 Sm 0.15 Gd 0.15 O 2-δ The oxygen ion conductivity of the particles at 400 ° C is about 1.5×10 -5 S•cm -1 .

[0184] Comparative Example 4

[0185] The difference between this comparative example and Example 8 is that the thickness of the tiled film on the Pt sheet is increased to 1.5 mm.

[0186] The transmission electron microscopy of the particles after quenching in this comparative example is as follows Figure 22 As shown, no Ce was found on the particle surface or in the blank area. 0.9 La 0.15 Sm 0.15 Gd 0.15 O 2-δ Nanosheets and nanoclusters. Since nanosheets or nanoclusters cannot be obtained, Ce 0.9 La 0.15 Sm 0.15 Gd 0.15 O 2-δ The oxygen ion conductivity of the particles at 400 ° C is about 1.5×10 -5 S•cm -1 .

[0187] Comparative Example 5

[0188] The difference between this comparative example and Example 5 is that: the Pr 0.5 Sr 0.5 CoO 3-δ Replaced by Pr 0.5 Sr 0.5 CoO 3-δ Blocks, such as Figure 23 As shown in (a), the block has a diameter of about 10 mm and a thickness of about 5 mm.

[0189] The transmission electron microscope of the sample after quenching and breaking in this comparative example is as follows: Figure 23 As shown in (b), no nanosheets or nanoclusters were observed. Since no nanosheets or nanoclusters were produced, the oxygen ion conductivity of the material remained the same as the oxygen ion conductivity of the parent material at 400°C, 2.1×10 -4 S•cm -1 .

[0190] When metal oxide blocks or particles with a size exceeding 500 nm or a large number of particles piled up with a thickness exceeding 1 mm are quenched, the high temperature will cause the surrounding low-temperature liquefied gases such as liquid nitrogen or liquid helium to vaporize, forming a nitrogen or helium layer between the metal oxide and the liquid nitrogen or liquid helium, which hinders the rapid conduction of heat, making it difficult to form a large temperature gradient and thermal stress on the surface of the metal oxide particles, and thus making it impossible to effectively peel the metal oxide surface.

[0191] Comparative Example 6

[0192] The difference between this comparative example and Example 5 is that the metal oxide Pr 0.5 Sr 0.5 CoO 3-δ Replaced by Pr 0.5 Ba 0.25 Ca 0.25 CoO 3-δ 、La 0.6 Sr 0.4 Co 0.2 Fe 0.8 O 3-δ 、La 0.5 Sr 0.5 CoO 3-δ and Pr 0.5 Sr 0.5 Co 0.5 Ni 0.5 O 3-δ Nanoparticles.

[0193] like Figure 24 、 25 As shown in Figures 26 and 27, no nanosheets or clusters were observed after quenching. 3-δ When the nanosheets or clusters of the perovskite structure material are prepared using the method disclosed in the present invention, the perovskite structure material cannot contain any of the elements such as La, Ca, Fe and Ni.

[0194] Comparative Example 7

[0195] The difference between this comparative example and Example 9 is that the quenching liquid is deionized water.

[0196] Figure 28 The transmission electron micrograph of the particles obtained in step (4) after deionized water quenching is shown. As can be seen from the figure, no cluster coating layer is observed on the surface of the material. No nanosheets and nanoclusters are obtained, so the oxygen ion conductivity is still the same as that of the parent material Bi 1.4 Te 0.6 LuO 4.3 Cl conductivity, its parent material Bi 1.4 Te 0.6 LuO 4.3 The oxygen ion conductivity of Cl at 400℃ is only 6.1×10 -3 S•cm -1 .

[0197] Comparative Example 8

[0198] The difference between this comparative example and Example 11 is that the quenching liquid is an aqueous solution of polyvinyl alcohol (mass fraction 0.2%).

[0199] Figure 29The transmission electron micrograph of the particles obtained in step (4) after the sample was quenched with deionized water is shown. As can be seen from the figure, no nanoclusters were observed on the surface of the material, but a large number of chemical defects were introduced into the periodic perovskite structure. This is related to the fact that polyvinyl alcohol forms a protective film during the quenching process, which reduces the Gd 0.5 Ba 0.25 Sr 0.25 Ce 0.5 Mn 0.5 O 3-δ The oxygen ion conductivity of the material obtained in Comparative Example 8 at 400°C is only 8.5×10 -6 S•cm -1 , smaller than its parent material Gd 0.5 Ba 0.25 Sr 0.25 Ce 0.5 Mn 0.5 O 3-δ The oxygen ion conductivity at 400℃ is only 1.3×10 -5 S•cm -1 .

[0200] Cryogenic liquefied gases, such as liquid nitrogen, liquid helium, liquid argon, and liquid oxygen, are used as quenching media in the present preparation method. This quenching fluid can promptly remove the exploded nanoclusters during quenching, facilitating the continued explosion process. The lower temperature of the quenching fluid compared to room temperature deionized water-based quenching fluids leads to a higher temperature gradient during the explosion process, another important factor in obtaining more nanoclusters in cryogenic liquefied gases.

[0201] In the present invention, metal oxide nanoclusters or metal oxide nanosheets composed of only a limited number of metal and oxygen atoms achieve a high thermal conductivity of 2.7 S·cm at 400°C. -1 The excellent ionic conductivity is better than that of traditional oxide ion conductors (including GDC (Gd 0.1 Ce 0.9 O 2-δ )、La 0.8 Sr 0.2 Ga 0.83 Mg 0.17 O 2.815 , YSZ and other benchmark materials) has increased its oxygen ion conductivity by three to four orders of magnitude and surpassed the best conductor Bi 1.9 Te 0.1 LuO 4.05The ultrahigh performance of the metal oxide nanoclusters or metal oxide nanosheets obtained by the present invention stems from the highly disordered amorphous structure of the clusters, which is rich in free oxygen vacancies, or the unique crystal structure of the ultrathin nanosheets. This configuration not only reduces the vacancy formation energy but also inhibits the aggregation of vacancies into low-conductivity chemical defect clusters. Therefore, in the absence of long-range crystalline order, the interactions between clusters or nanosheets, driven by an unsaturated coordination environment and ultrahigh specific surface area, can still achieve efficient ion conduction.

[0202] The above-mentioned embodiments merely express the implementation methods of the present invention. The description thereof is relatively specific and detailed, but it cannot be understood as limiting the patent scope of the present invention. Any technical solution obtained in the form of equivalent replacement or equivalent transformation should fall within the scope of protection of the present invention.

Claims

1. A method for preparing a metal oxide capable of conducting oxygen ions, characterized in that: It includes the following steps: The metal oxide with a particle size of less than 500 nm is spread on the carrier with a thickness of less than 1 mm, and then sintered at a high temperature; After sintering, the high-temperature metal oxide is rapidly quenched; after the metal oxide is cooled, the material is collected and dispersed in a dispersion liquid, and finally extracted and peeled from the dispersion liquid to obtain metal oxide nanosheets or metal oxide nanoclusters; During sintering, the sintering temperature is 1000-1500°C; The quenching fluid used for quenching includes cryogenic liquefied gas; The metal oxide nanosheets are fluorite structures and the components are Ce 1-x A x O 2-δ , wherein A is at least one of La, Pr, Nd, Sm and Gd, 0≤x≤0.5, and δ represents a variable whose valence state of the metal oxide varies with temperature and chemical defect environment and oxygen content; or, The metal oxide nanosheets are layered fluorite structures, and the components are Bi 2−x Te x LuO 4+x / 2 Cl, where 0≤x≤0.6; or The metal oxide nanosheet has a perovskite structure and its components are ABO 3-δ , wherein A is at least one of Pr, Nd, Sm, Gd, Sr, Ba, and Ce, B is at least one of Co, Mn, Mo, Bi, Ce, Ga, and Mg, and δ represents a variable that changes the valence of the metal oxide with the oxygen content depending on the temperature and chemical defect environment; or, The metal oxide nanosheet has a double perovskite structure and its components are AA'B2O 5+δ , wherein A is at least one of Pr, Nd, Sm, and Gd, A' is one or a combination of two of Ba and Sr, B is one or more of Co, Mn, Cu, and Mo, and δ represents a variable that changes with the valence of the metal oxide and the oxygen content as the temperature and chemical defect environment change; The metal oxide nanocluster component is Ce-AO, wherein A is at least one of La, Pr, Nd, Sm and Gd; wherein Ce accounts for 50%-100% of the molar content of the metal cations, and A accounts for 0%-50% of the molar content of the metal cations; or, The metal oxide nanocluster component is Bi-Te-Lu-O-Cl, wherein Bi accounts for 5%-70% of the molar content of metal cations, Te accounts for 0%-10% of the molar content of metal cations, and Lu accounts for 30%-40% of the molar content of metal cations; or, The metal oxide nanocluster components are ABO, wherein A is at least one of Pr, Nd, Sm, Gd, Sr, Ba and Ce, and B is at least one of Co, Mn, Mo, Bi, Ce, Ga and Mg; wherein A accounts for 40%-60% of the molar content of the metal cations, and B accounts for 40%-60% of the molar content of the metal cations; or, The metal oxide nanocluster components are A-A'-B, wherein A is at least one of Pr, Nd, Sm and Gd, A' is one or a combination of two of Ba and Sr, and B is one or more of Co, Mn, Cu and Mo, wherein A accounts for 15%-35% of the molar content of metal cations, A' accounts for 15%-35% of the molar content of metal cations, and B accounts for 40%-60% of the molar content of metal cations.

2. The method for preparing a metal oxide capable of conducting oxygen ions according to claim 1, wherein: During the rapid quenching process, the time from taking out the high-temperature metal oxide to immersing it in the quenching liquid is ≤20s.

3. A metal oxide capable of conducting oxygen ions, characterized in that: The metal oxide nanosheets or metal oxide nanoclusters are prepared by the preparation method as claimed in claim 1.

4. The oxygen ion conductive metal oxide according to claim 3, characterized in that The thickness of the metal oxide nanosheet is within 3 nm, and the sheet diameter is less than 500 nm.

5. The oxygen ion conductive metal oxide according to claim 3, characterized in that The metal oxide nanoclusters are disordered cluster structures composed of several to thousands of atoms.

6. Any of the following applications of metal oxides that can conduct oxygen ions as conductive materials: Application in the preparation of solid oxide battery electrolytes; Application in the preparation of battery electrode materials; Application in the preparation of oxygen separation membranes; Application in the preparation of electrode materials for chemical sensors; Application in the preparation of support materials for catalytic conversion of chemicals; in, The metal oxide capable of conducting oxygen ions refers to the metal oxide nanosheets or metal oxide nanoclusters prepared by the preparation method according to claim 1 or according to claim 3.

7. The use according to claim 6, characterized in that The battery electrode material includes a metal-air battery oxygen electrode material.

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