Anode oxygen evolution catalytic material for water electrolysis hydrogen production as well as preparation method and application of anode oxygen evolution catalytic material

Abstract

The invention discloses an anode oxygen evolution catalytic material for water electrolysis hydrogen production as well as a preparation method and application of the anode oxygen evolution catalytic material, and belongs to the field of composite materials and catalysts. The catalytic material comprises a quaternary metal compound, wherein the quaternary metal compound at least comprises nickel, iron, cobalt and tungsten; in the quaternary metal compound, the molar ratio of tungsten to cobalt is (1-3): (1-8); the molar ratio of cobalt to the sum of iron and nickel is (10-5): (8-1). The synergistic effect of quaternary transition metals in the catalytic material increases the electrochemical active area of the catalytic material, the water electrolysis oxygen evolution activity of the catalytic material is greatly improved, and the generation of an amorphous structure is also beneficial to the exposure of active sites of the catalyst. The catalytic material is synthesized by adopting a reflux etching method, the preparation method is simple, reaction conditions are easy to control, the cost is low, the nano catalytic material with uniform morphology and excellent performance can be obtained, and the nano catalytic material is used for preparing hydrogen energy by electrolyzing water and can remarkably reduce the overpotential of an anode in the water electrolyzing process.

Description

Technical Field

[0001] The invention belongs to the field of composite materials and catalysts, and relates to a catalytic material for anode oxygen evolution for electrolysis of water to produce hydrogen, and a preparation method and application thereof. Background Art

[0002] At present, my country's fossil energy mining is facing the risk of exhaustion. In addition, coupled with the environmental pollution caused by the burning of fossil energy, the development of new energy has become an important development direction. Although the emergence of wind energy, solar energy and tidal energy has injected new vitality into the energy field, the harsh environmental and geographical requirements and unstable storage methods have severely restricted their future development and application. Hydrogen production by water electrolysis is a very promising energy generation and storage method. On the one hand, hydrogen energy itself has the advantages of high energy density, easy storage and pollution-free combustion products. On the other hand, the electricity converted from wind power, water power and sunlight can be stored in the form of hydrogen energy in a more stable and efficient manner, and it is easy to transport. From the reaction mechanism, hydrogen production by water electrolysis is mainly divided into two electrode reactions: cathode hydrogen evolution reaction (HER) and anode oxygen evolution reaction (OER). However, due to the existence of polarization, both electrodes produce higher overpotentials, which makes the voltage applied to the electrolytic water tank higher than the theoretical decomposition voltage, greatly reducing the energy conversion efficiency. Reducing the anode overpotential is the key to improving the performance of oxygen evolution catalysts, and plays a decisive role in improving the efficiency of water electrolysis and reducing energy loss.

[0003] At present, the most commonly used catalysts for oxygen evolution reaction in water electrolysis are mainly noble metal oxides such as ruthenium oxide and iridium oxide. Although these catalysts are stable in operation, they still have the following problems: (1) low reserves and high costs; (2) low catalytic activity for oxygen evolution reaction, which results in high overpotential (10 mA cm -2 Under the current density, the overpotential of ruthenium oxide and iridium oxide is not less than 350mV), which leads to the transition loss and waste of electric energy. These two problems seriously restrict the large-scale application of such catalysts in industrial production. Summary of the invention

[0004] In view of the above problems, the present invention provides the following technical solutions:

[0005] A catalytic material comprises a quaternary metal complex, wherein the quaternary metal complex comprises at least nickel, iron, cobalt and tungsten.

[0006] According to an embodiment of the present invention, in the quaternary metal composite, the molar ratio of tungsten to cobalt is (1-3):(1-8), for example, 1:7.

[0007] According to an embodiment of the present invention, in the quaternary metal composite, the molar ratio of cobalt to the sum of iron and nickel is (10-5):(8-1), preferably (10-5):(6-1), for example, 10:6, 10:3.

[0008] According to an embodiment of the present invention, the quaternary metal complex is a hollow nanoparticle having an amorphous structure.

[0009] According to an embodiment of the present invention, the quaternary metal complex is obtained by etching the ZIF precursor with tungstate.

[0010] According to an embodiment of the present invention, the mass ratio of the ZIF precursor to tungstate is 1:(0.1-5), preferably 1:(0.5-2), for example 1:1.

[0011] According to an embodiment of the present invention, the ZIF precursor includes at least nickel, iron and cobalt.

[0012] According to an embodiment of the present invention, in the ZIF precursor, the molar ratio of cobalt to the sum of iron and nickel is (10-5):(8-1), preferably (10-5):(6-1), for example, 10:6, 10:3.

[0013] According to an embodiment of the present invention, in the catalytic material, the quaternary metal complex is a hollow nanoparticle. In the present invention, the hollow nanoparticles of the catalytic material have a porous structure, which is generated by etching the ZIF precursor with tungstate, so that the catalytic material of the present invention has a high electrochemical active area and exposes more catalytic active sites.

[0014] According to an embodiment of the present invention, in the catalytic material, the quaternary metal complex has a higher electrochemical active area, better hydrophilicity and more catalytic active sites than the ZIF precursor.

[0015] According to an embodiment of the present invention, the catalytic material has a lower oxygen evolution overpotential. Specifically, at a current density of 10 mA cm -2 When the current density is 50 mA cm -2 When the catalyst material is used as the catalyst, the oxygen evolution overpotential is not greater than 400 mV, for example, 390 mV.

[0016] The present invention also provides a method for preparing the above-mentioned catalytic material, the method comprising the following steps:

[0017] 1) Preparation of ZIF precursor;

[0018] 2) The ZIF precursor in step 1) is mixed with tungstate, and after etching, the catalytic material is obtained.

[0019] According to an embodiment of the present invention, in step 1), the ZIF precursor includes cobalt, iron and nickel.

[0020] According to an embodiment of the present invention, in step 1), the method for synthesizing the ZIF precursor comprises: mixing a cobalt salt, an iron salt and a nickel salt, and then adding a ligand to synthesize the ZIF precursor.

[0021] According to an embodiment of the present invention, in the synthesis method of the ZIF precursor, the molar ratio of the cobalt element in the cobalt salt to the sum of the iron element in the iron salt and the nickel element in the nickel salt is (10-5):(8-1), preferably (10-5):(6-1), for example, 10:6, 10:3.

[0022] According to an embodiment of the present invention, the cobalt salt is selected from one of cobalt chloride, cobalt nitrate and cobalt sulfate.

[0023] According to an embodiment of the present invention, the iron salt is selected from one of ferrous chloride, ferric nitrate and ferrous sulfate.

[0024] According to an embodiment of the present invention, the nickel salt is selected from one of nickel chloride, nickel nitrate and nickel sulfate.

[0025] According to an embodiment of the present invention, in the synthesis method of the ZIF precursor, the ligand is selected from 2-methylimidazole.

[0026] According to an embodiment of the present invention, the molar ratio of the ligand to the cobalt salt is 1:(0.1-20), preferably 1:(0.1-10), 1:(0.1-5), for example 1:1.

[0027] According to an embodiment of the present invention, the synthesis conditions of the ZIF precursor include: a synthesis temperature of 10-30°C, for example, room temperature; a synthesis time of 0.1 to 3 hours, for example, 0.1 hour, 0.5 hour, 1 hour, 1.5 hours, 2 hours, 2.5 hours, 3 hours, preferably 0.1 to 1.5 hours.

[0028] According to an embodiment of the present invention, the synthesis method of the ZIF precursor further comprises cleaning the ZIF precursor. Specifically, the cleaning step refers to: centrifuging and washing the ZIF precursor with a washing solvent. Preferably, the washing solvent is selected from one of deionized water and / or anhydrous ethanol, methanol, and N,N-dimethylformamide. The washing solvent is not specifically limited in the present invention, as long as it can remove unreacted nickel salts, cobalt salts, iron salts and ligands.

[0029] According to an embodiment of the present invention, the number of centrifugal washing may be 2 to 10 times.

[0030] Exemplarily, the steps of washing the ZIF precursor are as follows: disperse the ZIF precursor in deionized water and / or anhydrous ethanol in turn, shake and wash it, then centrifuge it, wash it repeatedly for several times (e.g., 2 to 10 times), then take it out, wash it, and dry it to obtain a pure product.

[0031] According to an embodiment of the present invention, in step 2), the etching specifically comprises: dispersing the ZIF precursor obtained in step 1) in anhydrous ethanol, and subjecting the resulting mixture to a reflux reaction with a solution containing tungstate.

[0032] According to an embodiment of the present invention, in step 2), the mass ratio of the ZIF precursor to tungstate is 1:(0.1-5), preferably 1:(0.5-2), for example 1:1.

[0033] According to an embodiment of the present invention, in step 2), the tungstate is selected from at least one or more of sodium tungstate, potassium tungstate, cobalt tungstate, and sodium metatungstate.

[0034] According to an embodiment of the present invention, in step 2, in the solution containing tungstate, the concentration of tungstate is 0.01 to 1 mol / L, preferably 0.01 to 0.5 mol / L.

[0035] According to an embodiment of the present invention, in step 2), the heating temperature of the reflux reaction may be 50 to 200° C., and the heating time of the reflux reaction may be 1 to 5 hours.

[0036] According to an embodiment of the present invention, in step 2), the etching further includes washing and / or drying.

[0037] According to an embodiment of the present invention, the washing comprises centrifugal washing with a washing solvent, and the washing solvent has the meaning as described above.

[0038] According to the embodiment of the present invention, the drying may be carried out by any method known in the art, as long as the catalytic material can be obtained.

[0039] The present invention also provides a catalytic material prepared by the above preparation method, and the catalytic material has the meaning as described above.

[0040] The present invention also provides a use of the catalytic material, which is used for producing hydrogen by electrolysis of water; specifically, used as a catalyst loaded on an anode in producing hydrogen by electrolysis of water.

[0041] The present invention also provides a method for producing hydrogen by electrolyzing water, wherein the above-mentioned catalytic material is used, and the catalytic material is used as a catalyst loaded on an anode.

[0042] According to an embodiment of the present invention, the anode has a lower oxygen evolution overpotential. Specifically, at a current density of 10 mA cm -2 The oxygen evolution overpotential is not greater than 300 mV, for example, 298 mV; specifically, at a current density of 50 mA cm -2 The oxygen evolution overpotential is not greater than 400 mV, for example 390 mV.

[0043] Beneficial Effects

[0044] (1) The present invention provides a catalytic material for oxygen evolution at the anode of electrolyzed water, which is a quaternary metal composite. The catalytic material of the present invention has low cost, simple preparation, and high oxygen evolution catalytic activity and stability. Specifically, the catalytic material for oxygen evolution at the anode of electrolyzed water has a low oxygen evolution overpotential and can be used as a catalyst for oxygen evolution at the anode of electrolyzed water.

[0045] (2) The present invention adopts a reflux etching method to synthesize the catalytic material. The preparation method is simple, the reaction conditions are easy to control, the cost is low, the process repeatability is good, and the oxygen evolution performance is excellent. A nano-catalytic material with uniform morphology and excellent performance can be obtained. The present invention reduces the preparation cost of the catalytic material and solves the corresponding problems of high cost and low activity of industrial precious metal oxide catalysts. Moreover, the electrolytic water anode oxygen evolution catalytic material is used for electrolysis of water to produce hydrogen energy, which can significantly reduce the overpotential of the anode during the electrolysis of water (for example, at a current density of 10 mA cm -2 When the current density is 50 mA cm -2 When the oxygen evolution overpotential of the catalytic material is not greater than 400 mV, for example, 390 mV), it has far-reaching significance for realizing the industrialization of energy-saving hydrogen production.

[0046] (3) The catalytic material of the present invention is used as an oxygen evolution catalyst at the anode of water electrolysis. The synergistic effect of the quaternary transition metal increases its electrochemical active area, greatly improving its oxygen evolution activity at the anode of water electrolysis. The presence of the amorphous structure can adjust the electronic structure of the catalytic material, enhance the oxygen evolution activity at the anode of water electrolysis, and is also beneficial to the exposure of the catalyst active sites. BRIEF DESCRIPTION OF THE DRAWINGS

[0047] Figure 1 is a transmission electron microscope image of the catalytic material obtained in Example 1;

[0048] Figure 2 This is the OER performance diagram of the catalytic material obtained in Example 1. DETAILED DESCRIPTION

[0049] The technical scheme of the present invention will be further described in detail below in conjunction with specific embodiments. It should be understood that the following embodiments are only exemplary descriptions and explanations of the present invention and should not be construed as limiting the scope of protection of the present invention. All technologies implemented based on the above content of the present invention are included in the scope that the present invention is intended to protect.

[0050] Unless otherwise specified, the raw materials and reagents used in the following examples are commercially available or can be prepared by known methods.

[0051] Example 1

[0052] (1) Dissolve cobalt chloride, ferrous chloride and nickel chloride in deionized water at a Co:Fe:Ni molar ratio of 10:5:1, and mix them by ultrasonication and oscillation to form a uniform mixed salt solution. Separately, weigh 2-methylimidazole in the same molar ratio as cobalt chloride and dissolve it in deionized water, and mix them by ultrasonication and oscillation to form a uniform 2-methylimidazole solution;

[0053] (2) mixing the mixed salt solution obtained in step (1) with the 2-methylimidazole solution, reacting for 0.1 hour, centrifuging, washing and drying the obtained product to obtain a nickel-iron co-doped ZIF precursor;

[0054] (3) dissolving the ZIF precursor obtained in step (2) in anhydrous ethanol, dispersing by ultrasonication and oscillation to obtain a ZIF precursor solution; separately weighing sodium metatungstate of the same mass as the ZIF precursor, dissolving it in deionized water, and dispersing it by ultrasonication and oscillation to form a uniform sodium tungstate solution;

[0055] (4) The ZIF precursor solution obtained in step (3) is mixed with the sodium metatungstate solution, stirred, and refluxed for 3 hours at a temperature of 90° C. to obtain the final product catalyst, which is centrifuged and washed (washing refers to washing with ethanol and water, respectively), and dried in an oven at 60° C. to obtain a quaternary metal complex, which contains Ni, Fe, Co, and W.

[0056] Figure 1 is a transmission electron microscope image of the material obtained in Example 1; Figure 1 It can be seen that the quaternary metal composite prepared in this example is a hollow nanoparticle with an amorphous structure.

[0057] Figure 2 is the OER performance diagram of the quaternary metal catalyst obtained in Example 1 and its respective control groups; Figure 2 It can be seen that the co-doping of nickel and iron bimetallics changes the original complete crystalline structure of the ZIF precursor, and the disorder of the structure enhances the catalytic activity of the catalyst.

[0058] Example 1-1

[0059] The method for preparing the quaternary metal composite in this embodiment is basically the same as that in embodiment 1, except that:

[0060] In step (3), sodium metatungstate is weighed and dissolved in deionized water, and the mass ratio of sodium metatungstate to ZIF-67 precursor is 0.5:1, 1.5:1, and 2:1, respectively, and dispersed into uniform sodium tungstate solutions of different concentrations by ultrasonic and oscillation;

[0061] In step (4), sodium tungstate solutions of different concentrations are mixed and stirred with ZIF precursor solutions (i.e., the mass ratios of sodium metatungstate to ZIF-67 precursor are 0.5:1, 1.5:1, and 2:1, respectively), and refluxed for 3 hours at a temperature of 90°C to obtain the final product catalysts, which are centrifuged and washed (washing refers to washing with ethanol and water, respectively), and dried in an oven at 60°C to obtain different quaternary metal complexes, which are respectively recorded as quaternary metal complexes 1-A, 1-B, and 1-C.

[0062] Example 1-2

[0063] The method for preparing the quaternary metal composite in this embodiment is basically the same as that in embodiment 1, except that:

[0064] In step (4), 4 portions of sodium tungstate solution are mixed and stirred with the ZIF precursor solution, and the mass ratio of sodium metatungstate to ZIF-67 precursor is 1:1, and reflux is performed for 1 hour, 2 hours, 4 hours and 5 hours, respectively, and the reflux temperature is 90°C. The final product catalyst is obtained and centrifuged and washed (washing refers to washing with ethanol and water, respectively), and dried in an oven at 60°C to obtain different quaternary metal complexes, which are respectively recorded as quaternary metal complexes 2-A, 2-B, 2-C, and 2-D.

[0065] Test Example 1

[0066] (1) The quaternary metal composite prepared in Example 1 was used as a catalyst to test the electrocatalytic oxygen evolution performance:

[0067] 5 mg of the catalyst was dispersed in a mixed solvent containing 50 μL of 5% Nafion solution (DuPont D520), 125 μL of anhydrous ethanol, and 375 μL of deionized water, and dispersed by ultrasonication and oscillation for 1 hour to obtain a catalyst dispersion;

[0068] 5 μL of the obtained catalyst dispersion was evenly dropped onto the surface of a glassy carbon electrode with a diameter of 3 mm. The oxygen evolution performance was then tested on an electrochemical workstation using a three-electrode method (saturated calomel electrode as reference electrode and carbon rod as counter electrode). The electrolyte was 1 mol / L KOH and the current density was 10 mA cm -2, after solution impedance compensation (iR compensation), the overpotential is 298 mV.

[0069] (2) The quaternary metal composite prepared in Example 1-1 was used as a catalyst to test the electrocatalytic oxygen evolution performance:

[0070] By testing the oxygen evolution performance of the quaternary metal composites 1-A, 1-B, and 1-C according to the method of step (1) above, it can be seen that compared with the quaternary metal composite of Example 1, the overpotential of the quaternary metal composites 1-A, 1-B, and 1-C is slightly increased, for example, between 300-350 mV.

[0071] (3) The quaternary metal composite prepared in Example 1-2 was used as a catalyst to test the electrocatalytic oxygen evolution performance:

[0072] By testing the oxygen evolution performance of the quaternary metal composites 2-A, 2-B, 2-C, and 2-D according to the method of step (1) above, it can be seen that compared with the quaternary metal composite of Example 1, the overpotential of the quaternary metal composites 2-A, 2-B, 2-C, and 2-D is slightly increased, for example, between 300-350 mV.

[0073] Test Example 2

[0074] The quaternary metal composite prepared in Example 1 was used as a catalyst to test the electrocatalytic oxygen evolution performance:

[0075] Take 5 μL of the catalyst dispersion of Test Example 1 and evenly drop it onto the surface of a glassy carbon electrode with a diameter of 3 mm. Then, the oxygen evolution performance was tested on an electrochemical workstation using a three-electrode method (saturated calomel electrode as the reference electrode and carbon rod as the counter electrode). The electrolyte was 1 mol / L KOH and the current density was 50 mA cm -2 , after solution impedance compensation (iR compensation), the overpotential is 390 mV.

[0076] Example 2

[0077] (1) Dissolve cobalt chloride, ferric chloride and nickel chloride in deionized water at a Co:Fe:Ni molar ratio of 20:5:1, and mix them into a uniform mixed salt solution by ultrasonication and oscillation. Separately, weigh 2-methylimidazole in the same molar ratio as cobalt chloride and dissolve it in a certain volume of deionized water, and mix them into a uniform solution by ultrasonication and oscillation;

[0078] (2) mixing the mixed salt solution obtained in step (1) with the 2-methylimidazole solution, reacting for 0.1 hour, centrifuging, washing and drying the obtained product to obtain a nickel-iron co-doped ZIF precursor;

[0079] (3) dissolving the ZIF precursor obtained in step (2) in anhydrous ethanol, and dispersing by ultrasonication and oscillation; separately weighing potassium tungstate of the same mass as the ZIF precursor, dissolving it in deionized water, and dispersing it by ultrasonication and oscillation into a uniform solution;

[0080] (4) The product solution obtained in step (3) is mixed with the potassium tungstate solution, stirred, and refluxed at a temperature of 90° C. to obtain the final product catalyst, which is centrifuged and washed (washing refers to washing with ethanol and water respectively), and dried in an oven at 60° C. to obtain a quaternary metal complex, which contains Ni, Fe, Co, and W.

[0081] Test Example 3

[0082] The quaternary metal complex prepared in Example 2 was used as a catalyst to test the electrocatalytic oxygen evolution performance:

[0083] 4 mg of the catalyst was dispersed in a mixed solvent containing 50 μL of 5% Nafion solution (DuPont D520), 125 μL of anhydrous ethanol, and 375 μL of deionized water, and dispersed by ultrasonication and oscillation for 1 hour to obtain a catalyst dispersion;

[0084] 5 μL of the obtained catalyst dispersion was evenly dropped onto the surface of a glassy carbon electrode with a diameter of 3 mm. The oxygen evolution performance was then tested on an electrochemical workstation using a three-electrode method (saturated calomel electrode as reference electrode and carbon rod as counter electrode). The electrolyte was 1 mol / L KOH and the current density was 10 mA cm -2 , without solution impedance compensation (iR compensation), the overpotential is 325mV.

[0085] Test Example 4

[0086] The quaternary metal complex prepared in Example 2 was used as a catalyst to test the electrocatalytic oxygen evolution performance:

[0087] Take 5 μL of the catalyst dispersion of Test Example 3 and evenly drop it onto the surface of a glassy carbon electrode with a diameter of 3 mm. Then, the oxygen evolution performance was tested on an electrochemical workstation using a three-electrode method (saturated calomel electrode as the reference electrode and carbon rod as the counter electrode). The electrolyte was 1 mol / L KOH and the current density was 50 mA cm -2 , without solution impedance compensation (iR compensation), the overpotential is 444mV.

[0088] Comparative test example 1

[0089] The ZIF precursor in Example 1 was used as a catalyst to test the electrocatalytic oxygen evolution performance:

[0090] 5 mg of the ZIF precursor in Example 1 was dispersed in a mixed solvent containing 50 μL of 5% Nafion solution (DuPont D520), 125 μL of anhydrous ethanol, and 375 μL of deionized water. After being dispersed by ultrasonication and oscillation for 1 hour, a comparative catalyst dispersion was obtained.

[0091] 5 μL of the above catalyst dispersion was evenly dropped onto the surface of a glassy carbon electrode with a diameter of 3 mm. The oxygen evolution performance was then tested on an electrochemical workstation using a three-electrode method (saturated calomel electrode as reference electrode and carbon rod as counter electrode). The electrolyte was 1 mol / L KOH and the current density was 10 mA cm -2 After solution impedance compensation (iR compensation), the overpotential is not less than 400 mV. It can be seen that compared with the catalyst of Example 1, the overpotential is too high when the ZIF precursor is directly used as a catalyst.

[0092] The above is a description of the exemplary embodiments of the present invention. However, the protection scope of the present application is not limited to the above embodiments. Any modification, equivalent substitution, improvement, etc. made by those skilled in the art within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A catalytic material, characterized in that: The catalytic material includes a quaternary metal complex, and the quaternary metal complex includes at least nickel, iron, cobalt, and tungsten; In the quaternary metal composite, the molar ratio of tungsten to cobalt is (1-3):(1-8); the molar ratio of cobalt to the sum of iron and nickel is (10-5):(8-1).

2. The catalytic material according to claim 1, characterized in that The quaternary metal complex is a hollow nanoparticle with an amorphous structure.

3. Preferably, the quaternary metal complex is obtained by etching the ZIF precursor with tungstate. Preferably, the mass ratio of the ZIF precursor to tungstate is 1:(1-5). Preferably, the ZIF precursor comprises at least nickel, iron and cobalt. Preferably, in the ZIF precursor, the molar ratio of cobalt to the sum of iron and nickel is (10-5):(8-1).

4. Preferably, in the catalytic material, the quaternary metal complex is a hollow nanoparticle. Preferably, in the catalytic material, the quaternary metal complex has a higher electrochemical active area, better hydrophilicity and more catalytic active sites than the ZIF precursor. Preferably, at a current density of 10 mA cm -2 The oxygen evolution overpotential of the catalytic material is not greater than 300 mV. Preferably, at a current density of 50 mA cm -2 The oxygen evolution overpotential of the catalytic material is not greater than 400 mV.

5. The method for preparing the catalytic material according to any one of claims 1 to 4, characterized in that: The preparation method comprises the following steps: 1) Preparation of ZIF precursor; 2) The ZIF precursor in step 1) is mixed with tungstate, and after etching, the catalytic material is obtained.

6. The preparation method according to claim 5, characterized in that: In step 1), the ZIF precursor includes cobalt, iron and nickel. Preferably, in step 1), the method for synthesizing the ZIF precursor comprises: mixing a cobalt salt, an iron salt and a nickel salt, and then adding a ligand to synthesize the ZIF precursor. Preferably, in the synthesis method of the ZIF precursor, the molar ratio of the cobalt element in the cobalt salt to the sum of the iron element in the iron salt and the nickel element in the nickel salt is (10-5):(8-1).

7. The preparation method according to claim 5 or 6, characterized in that: The cobalt salt is selected from cobalt chloride, cobalt nitrate and cobalt sulfate. Preferably, the iron salt is selected from ferrous chloride, ferric nitrate and ferrous sulfate. Preferably, the nickel salt is selected from nickel chloride, nickel nitrate and nickel sulfate. Preferably, in the synthesis method of the ZIF precursor, the ligand is selected from 2-methylimidazole. Preferably, the molar ratio of the ligand to the cobalt salt is 1:(0.1-20). Preferably, the synthesis conditions of the ZIF precursor include: a synthesis temperature of 10-30° C.; and a synthesis time of 0.1 to 3 hours.

8. The preparation method according to any one of claims 5 to 7, characterized in that: In step 2), the etching specifically includes: dispersing the ZIF precursor obtained in step 1) in anhydrous ethanol, and performing a reflux reaction with a solution containing tungstate. Preferably, in step 2), the mass ratio of the ZIF precursor to tungstate is 1:(0.1-5). Preferably, in step 2), the tungstate is selected from at least one or more of sodium tungstate, potassium tungstate, cobalt tungstate, and sodium metatungstate. Preferably, in step 2, in the solution containing tungstate, the concentration of tungstate is 0.01-1 mol / L. Preferably, in step 2), the heating temperature of the reflux reaction is 50 to 200° C., and the heating time of the reflux reaction is 1 to 5 hours.

9. Use of the catalytic material according to any one of claims 1 to 4 for producing hydrogen by electrolysis of water.

10. A method for producing hydrogen by electrolysis of water, wherein the catalytic material according to any one of claims 1 to 4 is used as a catalyst loaded on an anode.

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