Metal organic framework loaded with metal nanoparticles as well as preparation method and application of metal organic framework

Abstract

The invention provides a metal organic framework loaded with metal nanoparticles as well as a preparation method and application thereof. The method comprises the following steps: providing a metal organic framework; mixing, heating and centrifugally drying a metal organic framework, a second ligand and a second solvent to obtain a ligand-modified metal organic framework, mixing the ligand-modified metal organic framework, a second metal salt and a third solvent to obtain a first mixed solution, and carrying out ultrasonic and centrifugally drying on the first mixed solution to obtain a second ligand-modified metal organic framework; the metal nanoparticles are loaded on the metal organic framework; or mixing the ligand modified metal organic framework, the second metal salt, the third solvent and the reducing agent to obtain a second mixed solution, and performing ultrasonic and centrifugal drying on the second mixed solution to obtain the metal organic framework loaded with the metal nanoparticles. Therefore, the metal ions can be uniformly distributed on the metal organic framework, and the catalytic activity of the metal nanoparticles is improved.

Description

Technical Field

[0001] The present application relates to the field of metal-organic frameworks, and in particular, to metal-organic frameworks loaded with metal nanoparticles, their preparation methods and applications. Background Art

[0002] Metal nanoparticles, nanoclusters and single atoms have long been a popular research direction due to their unique optoelectrochemical properties, mechanical properties and catalytic activities. Due to the "quantum size effect" of the nanoparticles themselves, their properties are affected by size. Taking gold nanoparticles as an example, a number of studies have shown that when their particle size is less than 5 nm, they can catalyze most chemical reactions, such as aerobic oxidation of ethanol or reduction of carbon dioxide. However, the high surface free energy leads to their poor stability, thus tending to aggregate and lose catalytic performance. Therefore, it is particularly important to reduce the size of metal nanoparticles as much as possible and seek a method that can effectively limit and stabilize the size of metal nanoparticles to improve the catalytic performance of materials.

[0003] Metal-organic frameworks have advantages such as high specific surface area, rich pore structures and adjustable structures, and have potential application values in catalysis, gas storage, energy storage, sensing, etc., thus being widely concerned. In addition, metal-organic frameworks can also be used as "containers" for doping single-atom catalysts and encapsulating nanoparticles. Due to their ultrathin nanosheet morphology and large lateral size, they have the function of anchoring metal nanoparticles. However, how to form uniformly distributed metal nanoparticles on metal-organic frameworks is a difficult problem. Summary of the Invention

[0004] The present application aims to solve at least one of the technical problems in the related art to some extent.

[0005] The first aspect of the present application provides a method for loading metal nanoparticles on a metal-organic framework, the method comprising:

[0006] Mixing and reacting a first metal salt, a regulator, a first ligand and a first solvent to prepare a metal-organic framework, wherein the metal in the first metal salt includes at least one of Zr, Fe, Co, Ni, Zn, Cu, Mg, Cr, Cd, Cu, Ce, Zr, Hf, Y;

[0007] Mixing the metal-organic framework, a second ligand and a second solvent, performing a first heating, centrifuging and drying to obtain a ligand-modified metal-organic framework, the second ligand including a compound shown in Formula Ι:

[0008] R 1 -A-R 2 Formula Ι,

[0009] wherein, R 1including -SH, -NH 2 , -OH, -COOH, -OCH 3 , -SCH 3 , -NO 2 , -CHO, -COOR, at least one of halogen atoms, A includes at least one of naphthalene, anthracene, phenanthrene, pyrene, pyridine, pyrazole, furan, thiophene, pyrrole, imidazole, oxazole, thiazole, dioxane, pyrimidine, R 2 includes at least one of -CHO, -COOR, -CONH 2 , -COR, -COX (X = F, Cl, Br, I);

[0010] Mix the ligand-modified metal-organic framework, the second metal salt, and the third solvent to obtain a first mixture, and subject the first mixture to ultrasonic treatment, second heating, and then centrifugal drying to obtain the metal-organic framework loaded with metal nanoparticles; or

[0011] Mix the ligand-modified metal-organic framework, the second metal salt, the third solvent, and a reducing agent to obtain a second mixture, and subject the second mixture to ultrasonic treatment, second heating, and then centrifugal drying to obtain the metal-organic framework loaded with metal nanoparticles;

[0012] The metal in the second metal salt includes at least one of Mn, Fe, Co, Ni, Cu, Zn, Nb, Mo, Tc, Ru, Rh, Pd, Ag, Cd, In, Sn, Te, W, Re, Os, Ir, Pt, Au, Hg, Pb, Bi, La, Ce, Pm, Nd.

[0013] The method for loading metal nanoparticles on a metal-organic framework proposed in this application introduces a second ligand in the process. Atoms such as S, O, and N in the second ligand can coordinate with metal atoms and be adsorbed into the metal-organic framework. Due to the porous structure of the metal-organic framework, metal ions can be evenly distributed on the metal-organic framework, and metal nanoparticles with a uniform size distribution are obtained by reaction, improving the catalytic performance of the metal nanoparticles.

[0014] According to some embodiments of the present application, the regulator includes at least one of benzoic acid, HF, HCl, H 2 O, sodium acetate, acetic acid, trifluoroacetic acid, picolinic acid.

[0015] According to some embodiments of the present application, the second ligand includes at least one of 4-mercaptobenzoic acid, 4-aminobenzoic acid, 4-hydroxybenzoic acid, pyrrole-3-carboxylic acid, 1H-pyrazole-4-carboxylic acid, 1H-1,2,4-triazole-3-carboxylic acid, 2-pyridinecarboxaldehyde, ferrocene carboxaldehyde. Optionally, the second ligand includes at least one of 4-mercaptobenzoic acid, 4-aminobenzoic acid, 4-hydroxybenzoic acid, 1H-pyrazole-4-carboxylic acid, 2-pyridinecarboxaldehyde, ferrocene carboxaldehyde. Thereby, the anchoring effect on metal atoms is improved.

[0016] According to some embodiments of the present application, the mass ratio of the second ligand to the metal-organic framework is (1:1000)-(1000:1), and may be (4:1).

[0017] According to some embodiments of the present application, the metal in the second metal salt includes at least one of Pt, Pd, Cu, Au, Ru, Ag, Ir, La.

[0018] According to some embodiments of the present application, the first ligand includes at least one of 1,3,6,8-tetrakis(4-carboxyphenyl)pyrene, terephthalic acid, 2-aminoterephthalic acid, tribenzoic acid, succinic acid, porphyrin and its derivatives, 2-methylimidazole, pyrene-based ligand, tetraphenylethylene ligand, porphyrin-based ligand.

[0019] According to some embodiments of the present application, the metal-organic framework includes at least one of the UIO-66 series, UIO-67 series, UIO-68 series, ZIFs series, IRs series, PCPs series, PCNs series, MILs series, NU-901, NU-1000.

[0020] According to some embodiments of the present application, at least one of the following conditions is satisfied: the concentrations of metal ions in the first mixed solution and the second mixed solution are independently 10 -5 mol / L - 1 mol / L; the temperature of the first heating is 30°C - 120°C, and the time of the first heating is 2 h - 60 h; the temperature of the second heating is 30°C - 100°C, and the time of the second heating is 10 min - 60 h.

[0021] The second aspect of the present application provides a metal-organic framework loaded with metal nanoparticles, which is prepared by the method provided in the first aspect of the present application.

[0022] The third aspect of the present application provides an application of a metal-organic framework loaded with metal nanoparticles in photocatalytic water splitting for hydrogen production. Description of the Drawings

[0023] The above and / or additional aspects and advantages of the present application will become apparent and be readily understood from the description of the embodiments in conjunction with the following drawings, wherein:

[0024] Figure 1 A flowchart showing a method for loading metal nanoparticles on a metal-organic framework according to an embodiment of the present application.

[0025] Figure 2 Infrared spectra of the modified metal-organic frameworks in Example 1, Example 2, Example 3, and Preparation Example of the present application are shown.

[0026] Figure 3 Powder X-ray diffraction (PXRD) spectra of the modified metal-organic frameworks in Example 1, Example 2, Example 3, and Preparation Example of the present application are shown.

[0027] Figure 4 PXRD spectra of the modified metal-organic frameworks loaded with Pt nanoparticles in Example 1, Example 2, Example 3, and Preparation Example of the present application are shown.

[0028] Figure 5 Aberration-corrected high-angle annular dark-field scanning transmission electron microscopy (AC-HAADF-STEM) images of Pt@NU-M prepared in Example 1 of the present application are shown.

[0029] Figure 6 Photocatalytic performance spectra of the metal-organic frameworks loaded with metal nanoparticles prepared in Example 1 - Example 3 and Preparation Example of the present application are shown.

[0030] Figure 7 Electrocatalytic performance spectra of the metal-organic frameworks loaded with metal nanoparticles prepared in Example 1 - Example 3 and Preparation Example of the present application are shown.

[0031] Figure 8 PXRD patterns of Pd@NU-M and Cu@NU-M prepared in Example 4 and Example 5 of the present application are shown.

[0032] Figure 9 Aberration-corrected high-angle annular dark-field scanning transmission electron microscopy (AC-HAADF-STEM) images of Pd@NU-M prepared in Example 4 of the present application are shown.

[0033] Figure 10 Aberration-corrected high-angle annular dark-field scanning transmission electron microscopy (AC-HAADF-STEM) images of Cu@NU-M prepared in Example 5 of the present application are shown.

[0034] Figure 11 Scanning electron microscopy (SEM) images of NU and NU-M in Example 1, Example 4, and Example 5 of the present application are shown.

[0035] Figure 12Shows the PXRD pattern of Pt@2-Pa-UIO-66-NH prepared in Example 6 of this application 2 of

[0036] Figure 13 Shows the PXRD pattern of Pt@Fc-UIO-66-NH prepared in Example 7 of this application 2 of

[0037] Figure 14 Shows the SEM image of Pt@2-Pa-UIO-66-NH prepared in Example 6 of this application 2 of

[0038] Figure 15 Shows the SEM image of Pt@Fc-UIO-66-NH prepared in Example 7 of this application 2 of

[0039] Figure 16 Shows the PXRD pattern of Au@NU-901-2N prepared in Example 8 of this application

[0040] Figure 17 Shows the AC-HAADF-STEM image of Au@NU-901-2N prepared in Example 8 of this application

[0041] Figure 18 Shows the SEM image of NU-901 prepared in Example 8 of this application

[0042] Figure 19 Shows the SEM image of Au@NU-901-2N prepared in Example 8 of this application

[0043] Figure 20 Shows the transmission electron microscope (TEM) image and energy-dispersive spectroscopy (EDS) spectrum of Pt@NU-M prepared in Example 1 of this application

[0044] Figure 21 Shows the TEM image and EDS spectrum of Pt@NU-H prepared in Example 2 of this application

[0045] Figure 22 Shows the TEM image and EDS spectrum of Pt@NU-A prepared in Example 3 of this application Detailed implementation mode

[0046] Embodiments of the present application will be described in detail below. The embodiments described below are exemplary and are only used to explain the present application, and should not be construed as a limitation to the present application. For those without specific techniques or conditions noted in the embodiments, they shall be carried out according to the techniques or conditions described in the literature in the field or according to the product specifications. For reagents or instruments without the manufacturer noted, they are all conventional products that can be obtained through commercial purchases.

[0047] The present application provides a method for loading metal nanoparticles on a metal-organic framework, the method comprising:

[0048] S10: Mixing and reacting a first metal salt, a regulator, a first ligand, and a first solvent to prepare a metal-organic framework

[0049] According to some embodiments of the present application, the method for preparing the metal-organic framework includes at least one of a hydrothermal method, a solution method, a gas-phase method, a gas-liquid interface synthesis method, a template method, a microwave-assisted synthesis method, and an ultrasonic-assisted synthesis method.

[0050] According to some embodiments of the present application, the first metal salt, the first solvent, the regulator, and the first ligand are added to a reaction vessel, ultrasonicated, cooled to room temperature after the reaction, and centrifuged and dried to obtain the metal-organic framework.

[0051] According to some embodiments of the present application, the first solvent includes at least one of water, N,N-dimethylformamide, methanol, cyclohexane, dichloromethane, acetone, N-methyl-2-pyrrolidone, o-dichlorobenzene, ethanol, methyl ethyl ketone, ethyl acetate, chloroform, carbon tetrachloride, benzene, toluene, xylene, ether, acetic acid, petroleum ether, n-hexane, dioxane, nitromethane, and butyl acetate.

[0052] According to some embodiments of the present application, the metal in the first metal salt includes at least one of Zr, Fe, Co, Ni, Zn, Cu, Mg, Cr, Cd, Cu, Ce, Zr, Hf, and Y.

[0053] According to some embodiments of the present application, the regulator includes at least one of benzoic acid, HF, HCl, H 2 O, sodium acetate, acetic acid, trifluoroacetic acid, and picolinic acid.

[0054] According to some embodiments of the present application, the ratio of the mass ratio of the regulator to the first ligand can be 1000-0.05. For example, it can be 1000, 500, 100, 10, 1, 0.1, 0.05, etc., or it can be a range composed of any of the above values.

[0055] According to some embodiments of the present application, the temperature during the ultrasonic process can be 25°C - 300°C. For example, it can be 25°C, 50°C, 100°C, 200°C, 300°C, etc., or it can be a range composed of any of the above values.

[0056] According to some embodiments of the present application, the time of the ultrasonic wave can be 0.5 h - 120 h.

[0057] According to some embodiments of the present application, the ratio of the mass of the first metal salt to the first ligand can be 0.001 - 1000. For example, it can be 0.001, 0.1, 1, 10, 50, 100, 500, 1000, etc., or it can be a range composed of any of the above values. Thereby, the synthesis efficiency of the metal-organic framework is improved.

[0058] According to some embodiments of the present application, the first ligand includes at least one of 1,3,6,8 - tetrakis(4 - carboxyphenyl)pyrene, terephthalic acid, 2 - aminoterephthalic acid, tribenzoic acid, succinic acid, porphyrin and its derivatives, 2 - methylimidazole, pyrene - based ligand, tetraphenylethylene - based ligand, and porphyrin - based ligand.

[0059] According to some embodiments of the present application, the pore size of the metal-organic framework is 0.1 nm - 10 nm.

[0060] According to some embodiments of the present application, the morphology of the metal-organic framework is not particularly limited. For example, it can be any one of spherical, flaky, layered, rhombic, cylindrical, cuboid, and cube.

[0061] According to some embodiments of the present application, the specific surface area of the metal-organic framework is 50 m 2 / g - 3000 m 2 / g. For example, it can be 50 m 2 / g, 100 m 2 / g, 500 m 2 / g, 1000 m 2 / g, 2000 m 2 / g, 3000 m 2 / g, etc., or it can be a range composed of any of the above values.

[0062] According to some embodiments of the present application, the metal-organic framework includes any one of the UIO-66 series, UIO-67 series, UIO-68 series, ZIFs series, IRs series, PCPs series, PCNs series, MILs series, NU-901, and NU-1000.

[0063] S20: Mix the metal-organic framework, the second ligand, and the second solvent, conduct the first heating, and then centrifuge and dry to obtain the ligand-modified metal-organic framework.

[0064] According to some embodiments of the present application, add the metal-organic framework to the second solvent, add the second ligand to the second solvent for the first heating, and after the reaction is completed, centrifuge and dry to obtain the modified metal-organic framework.

[0065] According to some embodiments of the present application, the second ligand includes at least one of 4-mercaptobenzoic acid, 4-aminobenzoic acid, 4-hydroxybenzoic acid, pyrrole-3-carboxylic acid, 1H-pyrazole-4-carboxylic acid, 1H-1,2,4-triazole-3-carboxylic acid, 2-pyridinecarboxaldehyde, and ferrocene carbaldehyde.

[0066] According to some embodiments of the present application, the second ligand includes at least one of 4-mercaptobenzoic acid, 4-aminobenzoic acid, 4-hydroxybenzoic acid, 1H-pyrazole-4-carboxylic acid, 2-pyridinecarboxaldehyde, and ferrocene carbaldehyde.

[0067] According to some embodiments of the present application, the mass ratio of the second ligand to the metal-organic framework is 0.001 - 1000. For example, it can be 0.001, 0.01, 0.1, 1, 10, 50, 100, 300, 600, 900, 1000, etc., or it can be a range composed of any of the above values. Thus, -SH, -NH 2 , -OH, -COOH, -OCH 3 , -SCH 3 , -NO 2 , -CHO, -COOR, and at least one of halogen atoms are introduced onto the metal-organic framework.

[0068] According to some embodiments of the present application, the second solvent includes at least one of water, N,N-dimethylformamide, methanol, cyclohexane, dichloromethane, acetone, N-methyl-2-pyrrolidone, o-dichlorobenzene, ethanol, butanone, ethyl acetate, chloroform, carbon tetrachloride, benzene, toluene, xylene, ether, acetic acid, petroleum ether, n-hexane, dioxane, nitromethane, and butyl acetate.

[0069] According to some embodiments of the present application, the temperature of the first heating can be 30°C - 120°C, and the time of the first heating can be 2h - 60h.

[0070] S30: Mix the ligand-modified metal-organic framework, the second metal salt, and the third solvent to obtain a first mixture, conduct ultrasonic treatment and the second heating on the first mixture, and then centrifuge and dry to obtain the metal-organic framework loaded with metal nanoparticles.

[0071] According to some embodiments of the present application, the ligand-modified metal-organic framework is added to a third solvent and ultrasonicated, and a second metal salt is added to obtain a first mixture, which is ultrasonicated, heated for the second time, and then centrifuged and dried to obtain a metal-organic framework loaded with metal nanoparticles.

[0072] According to some embodiments of the present application, the ligand-modified metal-organic framework is added to a third solvent for ultrasonicating and heating for the second time, a second metal salt and a reducing agent are added for reduction, and after the reaction is completed, it is centrifuged and dried to obtain a metal-organic framework loaded with metal nanoparticles.

[0073] According to some embodiments of the present application, the concentration of metal ions in the first mixture and the second mixture can be 10 -5 mol / L - 1 mol / L. For example, it can be 10 -5 mol / L, 10 -4 mol / L, 10 -3 mol / L, 10 -2 mol / L, 10 - 1 mol / L, 1 mol / L, etc., or can be a range composed of any of the above values. Thus, it is proved that this strategy can well anchor metal atoms.

[0074] According to some embodiments of the present application, the metal in the second metal salt includes at least one of Mn, Fe, Co, Ni, Cu, Zn, Nb, Mo, Tc, Ru, Rh, Pd, Ag, Cd, In, Sn, Te, W, Re, Os, Ir, Pt, Au, Hg, Pb, Bi, La, Ce, Pm, Nd.

[0075] According to some embodiments of the present application, the reducing agent includes at least one of sodium borohydride, hydrogen, carbon, carbon monoxide, sulfur dioxide, ferrous ion, iodide ion, bromide ion, lithium aluminum hydride, lithium triethylborohydride, ascorbic acid, sodium citrate, triethanolamine, stannous chloride, oxalic acid.

[0076] According to some embodiments of the present application, the ratio of the mass ratio of the reducing agent to the metal-organic framework can be 0.002 - 500. For example, it can be 0.002, 0.02, 0.2, 2, 20, 200, 300, 400, 500, etc., or can be a range composed of any of the above values. Thus, it is proved that this strategy has a high reduction efficiency.

[0077] According to some embodiments of the present application, the temperature of the second heating can be 30°C - 100°C, and the time of the second heating can be 10 min - 60 h.

[0078] The third solvent includes at least one of water, N,N-dimethylformamide, methanol, cyclohexane, dichloromethane, acetone, N-methyl-2-pyrrolidone, o-dichlorobenzene, ethanol, methyl ethyl ketone, ethyl acetate, chloroform, carbon tetrachloride, benzene, toluene, xylene, diethyl ether, acetic acid, petroleum ether, n-hexane, dioxane, nitromethane, and butyl acetate

[0079] The second aspect of the present application provides a metal-organic framework loaded with metal nanoparticles, which is prepared by the method provided in the first aspect of the present application

[0080] It should be noted that in the present application, the metal nanoparticles include nanoparticles formed by aggregation of single atoms or multiple atoms

[0081] The third aspect of the present application provides an application of a metal-organic framework loaded with metal nanoparticles in photocatalytic water splitting for hydrogen production

[0082] Example 1

[0083] Add 0.120 g of ZrCl 4 , 0.12 g of 1,3,6,8-tetrakis(4-carboxyphenyl)pyrene, 0.60 mL of water, 24.0 mL of dimethylformamide (DMF), and 1.40 mL of glacial acetic acid into a pressure-resistant tube, ultrasonicate for 30 min, place in an oven (120 °C, 24 h), after the reaction, wash / centrifuge three times with DMF, and then soak it in DMF solvent for activation to obtain the metal-organic framework solution NU

[0084] Add the above-synthesized metal-organic framework into a flask, then add 0.82 g of 4-mercaptobenzoic acid, heat using an oil bath (60 °C, 24 h), after the reaction, wash / centrifuge three times with ethanol and dry to obtain the modified metal-organic framework NU-M

[0085] Take 70 mg of the modified metal-organic framework and add it to 10 mL of water. After ultrasonication for 1 h, add 2 mL of H 2 PtCl 6 (1 g / L), stir for 1 h, then add 1.5 mL of NaBH 4 (4 g / L), after reduction for 30 min, wash / centrifuge three times with water and ethanol respectively, and dry to obtain the metal-organic framework Pt@NU-M loaded with Pt nanoparticles

[0086] Example 2

[0087] Add 0.120 g of ZrCl 4, 0.120 g of 1,3,6,8 - tetra(4 - carboxyphenyl)pyrene, 0.60 mL of water, 24.0 mL of DMF, and 1.40 mL of glacial acetic acid were added to a pressure - resistant tube, sonicated for 30 min, placed in an oven (120 °C, 24 h). After the reaction, it was washed / centrifuged three times with DMF, and then soaked in DMF solvent for activation to obtain the metal - organic framework solution NU.

[0088] The above - mentioned metal - organic framework was added to a flask, and then 0.73 g of 4 - hydroxybenzoic acid was added. It was heated using an oil - bath (60 °C, 24 h). After the reaction, it was washed / centrifuged three times with ethanol and dried to obtain the modified metal - organic framework NU - H.

[0089] 70 mg of the modified metal - organic framework was taken and added to 10 mL of water. After sonication for 1 h, 2 mL of H 2 PtCl 6 (1 g / L) was added. After stirring for 1 h, 1.5 mL of NaBH 4 (4 g / 1L) was added. After reduction for 30 min, it was washed / centrifuged three times with water and ethanol respectively and dried to obtain the metal - organic framework Pt@NU - H loaded with Pt nanoparticles.

[0090] Example 3

[0091] 0.120 g of ZrCl 4 , 0.120 g of 1,3,6,8 - tetra(4 - carboxyphenyl)pyrene, 0.60 mL of water, 24.0 mL of DMF, and 1.40 mL of glacial acetic acid were added to a pressure - resistant tube, sonicated for 30 min, placed in an oven (120 °C, 24 h). After the reaction, it was washed / centrifuged three times with DMF, and then soaked in DMF solvent for activation to obtain the metal - organic framework solution NU.

[0092] The above - mentioned metal - organic framework was added to a flask, and 0.72 g of 4 - aminobenzoic acid was added. It was heated using an oil - bath (60 °C, 24 h). After the reaction, it was washed / centrifuged three times with ethanol and dried to obtain the modified metal - organic framework NU - A.

[0093] 70 mg of the modified metal - organic framework was taken and added to 10 mL of water. After sonication for 1 h, 2 mL of H 2 PtCl 6 (1 g / L) was added. After stirring for 1 h, 1.5 mL of NaBH 4 (4 g / L) was added. After reduction for 30 min, it was washed / centrifuged three times with water and ethanol respectively and dried to obtain the metal - organic framework Pt@NU - A loaded with Pt nanoparticles.

[0094] Example 4

[0095] Add 0.120 g of ZrCl 4 , 0.120 g of 1,3,6,8 - tetrakis(4 - carboxyphenyl)pyrene, 0.60 mL of water, 24.0 mL of DMF, and 1.40 mL of glacial acetic acid into a pressure - resistant tube. Ultrasonic for 30 min, then place it in an oven (120 °C, 24 h). After the reaction is completed, wash / centrifuge three times with DMF, and then soak it in DMF solvent for activation to obtain the metal - organic framework solution NU.

[0096] Add the above - synthesized metal - organic framework into a flask, add 0.82 g of 4 - mercaptobenzoic acid, heat it using an oil - bath (60 °C, 24 h). After the reaction is completed, wash / centrifuge three times with ethanol and dry it to obtain the modified metal - organic framework NU - M.

[0097] Take 70 mg of the modified metal - organic framework and add it to 10 mL of water. After ultrasonic for 1 h, add 2 mL of PdCl 2 (1 g / L) hydrochloric acid solution. Stir for 1 h, then add 1.5 mL of NaBH 4 (4 g / L). After reduction for 30 min, wash / centrifuge three times with water and ethanol respectively, and dry it to obtain the metal - organic framework loaded with Pd nanoparticles, Pd@NU - M.

[0098] Example 5

[0099] Add 0.120 g of ZrCl 4 , 0.120 g of 1,3,6,8 - tetrakis(4 - carboxyphenyl)pyrene, 0.60 mL of water, 24.0 mL of DMF, and 1.40 mL of glacial acetic acid into a pressure - resistant tube. Ultrasonic for 30 min, then place it in an oven (120 °C, 24 h). After the reaction is completed, wash / centrifuge three times with DMF, and then soak it in DMF solvent for activation to obtain the target metal - organic framework solution NU.

[0100] Add the above - mentioned metal - organic framework into a flask, add 0.82 g of 4 - mercaptobenzoic acid, heat it using an oil - bath (60 °C, 24 h). After the reaction is completed, wash / centrifuge three times with ethanol and dry it to obtain the modified metal - organic framework NU - M.

[0101] Take 70 mg of the modified metal - organic framework and add it to 10 mL of water. After ultrasonic for 1 h, add Cu(NO 3 ) 2 (1 g / L) solution. Stir for 1 h, then add 1.5 mL of NaBH 4 (4 g / L). After reduction for 30 min, wash / centrifuge three times with water and ethanol respectively, and dry it to obtain the metal - organic framework loaded with Cu nanoparticles, Cu@NU - M.

[0102] Example 6

[0103] Add 23.2 mL of DMF, 1.8 mL of acetic acid, 0.0906 g of 2-aminoterephthalic acid, and 0.1166 g of ZrCl 4 to a 50 ml pressure-resistant tube, stir for 30 min, place in an oven (120 °C, 16 h), after the reaction, wash / centrifuge three times with ethanol and dry to obtain the modified metal-organic framework UIO-66-NH 2 .

[0104] Add 0.1 g of the above metal-organic framework to a flask, add 0.2292 mL of 2-pyridinecarboxaldehyde and 40 mL of acetonitrile, heat using an oil bath (70 °C, 72 h), after the reaction, wash / centrifuge three times with acetonitrile and methanol respectively and dry to obtain the modified metal-organic framework 2-Pa-UIO-66-NH 2 .

[0105] Take 60 mg of the modified metal-organic framework and add it to 10 mL of water. After ultrasonication for 1 h, add 2 mL of H 2 PtCl 6 (1 g / L) solution, stir for 1 h and then add 1.44 mL of NaBH 4 (4 g / L), after reduction for 20 min, wash / centrifuge three times with water and ethanol respectively, and dry to obtain the metal-organic framework Pt@2-Pa-UIO-66-NH loaded with Pt nanoparticles 2 .

[0106] Example 7

[0107] Add 23.2 mL of DMF, 1.8 mL of acetic acid, 0.0906 g of 2-aminoterephthalic acid, and 0.1166 g of ZrCl 4 to a 50 mL pressure-resistant tube, stir for 30 min, place in an oven (120 °C, 16 h), after the reaction, wash / centrifuge three times with ethanol to obtain the modified metal-organic framework UIO-66-NH 2 .

[0108] Add 0.1 g of the above metal-organic framework to a flask, add 0.113 g of ferrocene carbaldehyde and 40 mL of acetonitrile, heat using an oil bath (70 °C, 72 h), after the reaction, wash / centrifuge three times with acetonitrile and methanol respectively and dry to obtain the modified metal-organic framework Fc-UIO-66-NH 2 .

[0109] Take 60 mg of the modified metal-organic framework and add it to 10 mL of water. After ultrasonication for 1 h, add 2 mL of H 2 PtCl 6(1 g / L) solution, stir for 1 h and then add 1.44 mL of NaBH 4 (4 g / L), after reduction for 20 min, wash / centrifuge three times with water and ethanol respectively, and obtain metal-organic framework Pt@Fc-UIO-66-NH loaded with Pt nanoparticles after drying 2 .

[0110] Example 8

[0111] Add 97 mg of ZrOCl 2 8H 2 O, 0.7 g of benzoic acid and 8 mL of DMF into a pressure-resistant tube, ultrasonicate for 30 min, place in an oven and heat (80 °C, 1 h), after the reaction is completed, add 80 mg of 1,3,6,8-tetrakis(4-carboxyphenyl)pyrene, ultrasonicate for 1 h and then heat (120 °C, 24 h), after the reaction is completed, wash / centrifuge three times with DMF and methanol respectively to obtain a modified metal-organic framework NU-901 solution

[0112] Add the above metal-organic framework into a flask, add 0.3374 g of 1H-pyrazole-4-carboxylic acid and 10 mL of DMF, heat using an oil bath (60 °C, 24 h), after the reaction is completed, wash / centrifuge three times with DMF and ethanol respectively and dry to obtain a modified metal-organic framework NU-901-2N

[0113] Take 70 mg of the modified metal-organic framework and add it to 10 mL of water, ultrasonicate for 1 h and then add 0.22 mL of HAuCl 4 (10 g / L) solution, stir for 6 h and then wash / centrifuge three times with water and ethanol respectively, and obtain metal-organic framework Au@NU-901-2N loaded with Au nanoparticles after drying

[0114] As can be seen from the attached Figure 2 It can be seen that in Examples 1, 2, and 3 of this application, mercapto, hydroxyl, and amino groups were successfully modified on the metal-organic framework respectively

[0115] As can be seen from the attached Figure 3 It can be seen that after mercapto, hydroxyl, and amino groups were modified on the metal-organic framework in Examples 1, 2, and 3 of this application, the crystal structure of the metal-organic framework did not change

[0116] As can be seen from the attached Figure 4 It can be seen that after Pt nanoparticles were loaded on the metal-organic framework in Examples 1, 2, and 3 of this application, there were no large-sized Pt nanoparticles in the metal-organic framework, and the crystal structure of the metal-organic framework was not changed after loading Pt nanoparticles

[0117] As can be seen from the attached Figure 5It can be seen that in the Pt@NU-M prepared in Example 1 of the present application, Pt is distributed in the entire metal-organic framework in the form of single atoms.

[0118] From the attached Figure 6 and the attached Figure 7 It can be seen that the metal-organic frameworks loaded with Pt nanoparticles prepared in Example 1, Example 2, and Example 3 of the present application have excellent photoelectrocatalytic performance.

[0119] From the attached Figure 8 It can be seen that after Cu nanoparticles and Pd nanoparticles are respectively loaded on NU-M in Example 4 and Example 5 of the present application, there are no large-sized Pd nanoparticles in the metal-organic framework, and the crystal structure of the metal-organic framework is not changed after the Pd nanoparticles are loaded.

[0120] From the attached Figure 9 It can be seen that in the Pd@NU-M prepared in Example 4 of the present application, Pd is distributed in the entire metal-organic framework in the form of single atoms.

[0121] From the attached Figure 10 It can be seen that in the Cu@NU-M prepared in Example 5, Cu is distributed in the entire metal-organic framework in the form of single atoms.

[0122] From the attached Figure 11 It can be seen that the thiol modification in Example 1, Example 4, and Example 5 does not destroy the morphology of the metal-organic framework.

[0123] From the attached Figure 12 It can be seen that in the Pt@2-PA-UIO-66-NH prepared in Example 6 of the present application 2 , there are no large-sized Pt nanoparticles in the metal-organic framework, and the crystal structure of the metal-organic framework is not changed after the Pt nanoparticles are loaded.

[0124] From the attached Figure 13 It can be seen that in the Pt@Fc-UIO-66-NH prepared in Example 7 of the present application 2 , there are no large-sized Pt nanoparticles in the metal-organic framework, and the crystal structure of the metal-organic framework is not changed after the Pt nanoparticles are loaded.

[0125] From the attached Figure 14 It can be seen that by loading Pt nanoparticles on the metal-organic framework in Example 6 of the present application, the morphology of the metal-organic framework is not destroyed.

[0126] From the attached Figure 15 It can be seen that by loading Pt nanoparticles on the metal-organic framework in Example 7 of the present application, the morphology of the metal-organic framework is not destroyed.

[0127] From the attachedFigure 16 It can be seen that for the Au@NU-901-2N prepared in Example 8 of the present application, there are no large-sized Au nanoparticles in the metal-organic framework, and the crystal structure of the metal-organic framework is not changed after loading Au nanoparticles.

[0128] From the attached Figure 17 It can be seen that for the Pt@Fc-UIO-66-NH prepared in Example 7 of the present application 2 , there are no large-sized Au nanoparticles in the metal-organic framework, and Au is distributed in the entire metal-organic framework in the form of single atoms.

[0129] From the attached Figure 18 and the attached Figure 19 It can be seen that by loading Au nanoparticles on the metal-organic framework in Example 8 of the present application, the morphology of the metal-organic framework is not changed.

[0130] From the attached Figure 20 It can be seen that for the Pt@NU-M prepared in Example 1 of the present application, Pt is uniformly distributed on the metal-organic framework.

[0131] From the attached Figure 21 It can be seen that for the Pt@NU-H prepared in Example 2 of the present application, Pt is uniformly distributed on the metal-organic framework.

[0132] From the attached Figure 22 It can be seen that for the Pt@NU-A prepared in Example 3 of the present application, Pt is uniformly distributed on the metal-organic framework.

[0133] In the description of this specification, the description referring to terms such as "one embodiment", "some embodiments", "examples", "specific examples", or "some examples", etc. means that the specific features, structures, materials, or characteristics described in connection with the embodiment or example are included in at least one embodiment or example of the present application. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials, or characteristics described can be combined in a suitable manner in any one or more embodiments or examples. In addition, without contradiction, those skilled in the art can combine and combine the different embodiments or examples described in this specification and the features of different embodiments or examples.

[0134] Although the embodiments of the present application have been shown and described above, it can be understood that the above embodiments are exemplary and should not be construed as limiting the present application. Those of ordinary skill in the art can make changes, modifications, substitutions, and variations to the above embodiments within the scope of the present application.

Claims

1. A method for loading metal nanoparticles on a metal organic framework, characterized in that: include: Mixing a first metal salt, a regulator, a first ligand, and a first solvent to react to prepare a metal organic framework, wherein the metal in the first metal salt includes at least one of Zr, Fe, Co, Ni, Zn, Cu, Mg, Cr, Cd, Cu, Ce, Zr, Hf, and Y; The metal organic framework, the second ligand, and the second solvent are mixed, heated for the first time, and centrifuged to obtain a ligand-modified metal organic framework, wherein the second ligand includes a compound shown in Formula I: R1-A-R2 formula 1, Wherein, R1 includes at least one of -SH, -NH2, -OH, -COOH, -OCH3, -SCH3, -NO2, -CHO, -COOR, and a halogen atom; A includes at least one of naphthalene, anthracene, phenanthrene, pyrene, pyridine, pyrazole, furan, thiophene, pyrrole, imidazole, oxazole, thiazole, dioxane, and pyrimidine; and R2 includes at least one of -CHO, -COOR, -CONH2, -COR, and -COX (X=F, Cl, Br, I); The ligand-modified metal organic framework, the second metal salt, and the third solvent are mixed to obtain a first mixed solution, and the first mixed solution is subjected to ultrasound, a second heating, and then centrifugal drying to obtain a metal organic framework loaded with metal nanoparticles; or The ligand-modified metal organic framework, the second metal salt, the third solvent, and the reducing agent are mixed to obtain a second mixed solution, and the second mixed solution is subjected to ultrasound, a second heating, and then centrifugal drying to obtain the metal organic framework loaded with metal nanoparticles; The metal in the second metal salt includes at least one of Mn, Fe, Co, Ni, Cu, Zn, Nb, Mo, Tc, Ru, Rh, Pd, Ag, Cd, In, Sn, Te, W, Re, Os, Ir, Pt, Au, Hg, Pb, Bi, La, Ce, Pm, and Nd.

2. The method according to claim 1, characterized in that The regulator includes at least one of benzoic acid, HF, HCl, H2O, sodium acetate, acetic acid, trifluoroacetic acid, and picolinic acid.

3. The method according to claim 1 or 2, characterized in that: The second ligand includes at least one of 4-mercaptobenzoic acid, 4-aminobenzoic acid, 4-hydroxybenzoic acid, pyrrole-3-carboxylic acid, 1H-pyrazole-4-carboxylic acid, 1H-1,2,4-triazole-3-carboxylic acid, 2-pyridinecarboxaldehyde, and ferrocenecarboxaldehyde. Optionally, the second ligand includes at least one of 4-mercaptobenzoic acid, 4-aminobenzoic acid, 4-hydroxybenzoic acid, 1H-pyrazole-4-carboxylic acid, 2-pyridinecarboxaldehyde, and ferrocenecarboxaldehyde.

4. The method according to claim 1 or 2, characterized in that: The mass ratio of the second ligand to the metal organic framework is (1:1000)-(1000:1), and can be optionally (4:1).

5. The method according to claim 3, characterized in that: The metal in the second metal salt includes at least one of Pt, Pd, Cu, Au, Ru, Ag, Ir, and La.

6. The method according to claim 5, characterized in that The first ligand includes at least one of 1,3,6,8-tetrakis(4-carboxyphenyl)pyrene, terephthalic acid, 2-aminoterephthalic acid, tribenzoic acid, succinic acid, porphyrin and its derivatives, 2-methylimidazole, pyrene-based ligand, tetraphenylvinyl ligand, and porphyrin-based ligand.

7. The method according to claim 1, characterized in that The metal organic framework includes at least one of UIO-66 series, UIO-67 series, UIO-68 series, ZIFs series, IRs series, PCPs series, PCNs series, MILs series, NU-901, and NU-1000.

8. The method according to claim 1 or 2, characterized in that: Satisfy at least one of the following conditions: The concentrations of metal ions in the first mixed solution and the second mixed solution are independently 10 -5 mol / L-1mol / L; The temperature of the first heating is 30°C-120°C, and the time of the first heating is 2h-60h; The temperature of the second heating is 30° C.-100° C., and the time of the second heating is 10 min-60 h.

9. A metal organic framework loaded with metal nanoparticles, characterized in that: It is prepared by the method according to any one of claims 1 to 8.

10. Application of a metal organic framework loaded with metal nanoparticles in photocatalytic water hydrogen production.

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