Electrolyzed water catalyst as well as preparation method and application thereof

Abstract

The invention discloses an electrolyzed water catalyst as well as a preparation method and application thereof. The electrolyzed water catalyst comprises a substrate made of foamed nickel and a nickel oxide-containing nanosheet array perpendicular to the surface of the substrate. The catalyst provided by the invention has a special nanosheet array structure and shows excellent oxygen evolution performance, and the preparation method of the catalyst is simple, mild in condition, easily available in raw materials, low in equipment requirement and suitable for large-scale production.

Description

Technical Field

[0001] This invention relates to the field of water electrolysis for hydrogen production, specifically to a water electrolysis catalyst, its preparation method, and its application. Background Technology

[0002] The shortage of fossil fuels and environmental pollution are major challenges facing humanity today, and hydrogen energy is considered one of the most promising clean energy sources for the future energy structure. Traditional hydrogen production methods consume huge amounts of conventional energy, significantly increasing production costs and severely limiting the development and widespread application of hydrogen energy. Water electrolysis is considered an effective way to convert and store renewable energy. Anion exchange membrane electrolysis of water offers advantages such as high current density and fast response, and can use low-concentration alkaline solutions or water as the electrolyte. It also boasts multiple advantages including low cost and high efficiency, making it a highly anticipated water electrolysis technology for the future.

[0003] Noble metal-based catalysts such as Ru, Pt, and Ir are widely considered the most effective electrocatalysts, but their high cost and scarcity hinder their large-scale application. Non-noble metals, especially transition metal compounds such as Co-based, Ni-based, and Fe-based materials, are widely used as oxygen evolution catalysts due to their better stability in alkaline media. Therefore, the development of highly active non-noble metal catalysts is essential for the advancement of this field. Summary of the Invention

[0004] To address the problems existing in the prior art, this invention provides a water electrolysis catalyst, its preparation method, and its applications. This invention utilizes ultrathinning and heterogeneous composite strategies to significantly increase the active sites of the catalyst, enhance its intrinsic activity, and promote electron transport rates, thereby improving the performance of the water electrolysis catalyst.

[0005] One objective of this invention is to provide a water electrolysis catalyst, comprising a substrate made of nickel foam and an array of nickel oxide-containing nanosheets perpendicular to the surface of the substrate. Specifically, the water electrolysis catalyst is an ultrathin nanosheet array of a NiO heterostructure supported on nickel foam. This catalyst uses nickel foam as a substrate, with a NiO nanosheet array grown in situ perpendicular to the surface of the Ni substrate, and assembled with the substrate to form a Ni / NiO heterostructure, which can be simply referred to as "Ni / NiO composite material," "Ni / NiO material," or "Ni / NiO" in this invention. The NiO nanosheet array prepared by this invention has high bonding with the Ni substrate and exhibits excellent electrocatalytic performance. The oxygen evolution electrode catalyst prepared when the thickness of the Ni / NiO nanosheet array is ultrathin further enhances its oxygen evolution capacity.

[0006] In a preferred embodiment of the present invention,

[0007] The thickness of the nanosheet is 5-30 nm, such as 5 nm, 6 nm, 7 nm, 8 nm, 9 nm, 10 nm, 11 nm, 12 nm, 13 nm, 14 nm, 15 nm, 16 nm, 17 nm, 18 nm, 19 nm, 20 nm, 21 nm, 22 nm, 23 nm, 23 nm, 25 nm, 26 nm, 27 nm, 28 nm, 29 nm, 30 nm, or any intermediate value between two values, preferably 8-20 nm, more preferably 10-16 nm; and / or,

[0008] The thickness of the substrate is 0.2-6 mm, such as 0.2 mm, 0.5 mm, 1 mm, 1.5 mm, 2 mm, 2.5 mm, 3 mm, 3.5 mm, 4 mm, 4.5 mm, 5 mm, 5.5 mm, 6 mm, or any intermediate value between two values, preferably 0.5-3 mm, and more preferably 0.5-2 mm. The thickness change of the raw material nickel foam before and after the reaction is very small and negligible.

[0009] In a preferred embodiment of the present invention,

[0010] In the water electrolysis catalyst, the molar ratio of nickel to nickel oxide from the surface to a depth of 1 micrometer is (1-10):1, preferably (1.5-5):1.

[0011] A second objective of this invention is to provide a method for preparing a water electrolysis catalyst, which is one of the objectives of this invention, comprising the step of reacting nickel foam with a nitrate solution. This process allows NiO to be loaded onto the solution during its formation.

[0012] In a preferred embodiment of the present invention,

[0013] The nickel foam is in sheet form with a thickness of 0.2-6 mm, such as 0.2 mm, 0.5 mm, 1 mm, 1.5 mm, 2 mm, 2.5 mm, 3 mm, 3.5 mm, 4 mm, 4.5 mm, 5 mm, 5.5 mm, 6 mm, or any intermediate value between two values, preferably 0.5-3 mm, more preferably 0.5-2 mm; and / or, the porosity of the nickel foam is 60-95%, preferably 80-95%, more preferably 80-90%.

[0014] In a preferred embodiment of the present invention,

[0015] The nitrate is selected from at least one alkali metal nitrate, preferably from at least one of potassium nitrate and sodium nitrate; and / or,

[0016] The nitrate solution is an aqueous nitrate solution. Preferably, the concentration of the aqueous nitrate solution is 0.1-5 g / L, for example, 0.1 g / L, 0.2 g / L, 0.3 g / L, 0.4 g / L, 0.5 g / L, 0.6 g / L, 0.7 g / L, 0.8 g / L, 0.9 g / L, 1.0 g / L, 1.1 g / L, 1.2 g / L, 1.3 g / L, 1.4 g / L, or 1.5 g / L. The concentrations are 1.6 g / L, 1.7 g / L, 1.8 g / L, 1.9 g / L, 2.0 g / L, 2.1 g / L, 2.2 g / L, 2.3 g / L, 2.4 g / L, 2.5 g / L, 3 g / L, 3.5 g / L, 4.0 g / L, 4.5 g / L, 5.0 g / L, or any intermediate value between two values, preferably 0.3-2.5 g / L, more preferably 0.5-1.5 g / L.

[0017] In a preferred embodiment of the present invention,

[0018] The volume ratio of the nickel foam to the nitrate solution is 1:(50-150), preferably 1:(70-90).

[0019] In a preferred embodiment of the present invention,

[0020] The reaction conditions include: a reaction temperature of 80-150℃, preferably 90-120℃; and / or a reaction time of 6-15h, preferably 8-12h.

[0021] In a preferred embodiment of the present invention,

[0022] Before reacting with the nitrate solution, the foamed nickel also includes a first cleaning step; the purpose of the first cleaning is to remove grease, dust and other deposits from the surface of the carrier material.

[0023] Any cleaning method capable of achieving the above objectives is applicable to this invention. Preferably, the first cleaning includes the steps of sequentially cleaning the nickel foam with an organic solvent and an inorganic acid solution; more preferably,

[0024] The organic solvent is selected from at least one of organic solvents with ≤5 carbon atoms, preferably at least one of ethanol and acetone; and / or,

[0025] The inorganic acid solution is selected from at least one aqueous solution of sulfuric acid, hydrochloric acid, and nitric acid, preferably containing H+. + The concentration shall not exceed 3M, more preferably 0.5-2M; and / or,

[0026] The first cleaning is performed under ultrasonic conditions, preferably by ultrasonication in the organic solvent and inorganic acid solution for 5-60 min each, more preferably 10-40 min.

[0027] In a preferred embodiment of the present invention,

[0028] After the reaction between the nickel foam and the nitrate solution is completed, a second cleaning step is further included; the purpose of the second cleaning is to remove the reaction liquid from the surface of the material; preferably,

[0029] The second cleaning includes rinsing with water and / or an organic solvent; and / or,

[0030] After the second cleaning, a drying step is also included; more preferably,

[0031] The drying conditions include: a drying temperature of 20-60℃ and / or a drying time of 4-12 hours.

[0032] A third objective of this invention is to provide a method for producing hydrogen by electrolysis of water, using the water electrolysis catalyst of one objective of this invention or the water electrolysis catalyst prepared by the preparation method of another objective of this invention as the oxygen evolution electrode catalyst for producing hydrogen by electrolysis of water.

[0033] The fourth objective of this invention is to provide an application of the water electrolysis catalyst of one objective of this invention, or the water electrolysis catalyst prepared by the preparation method of the second objective of this invention, or the method of the third objective of this invention, in the field of hydrogen production by water electrolysis.

[0034] Through the above technical solution, the present invention can achieve at least the following beneficial effects:

[0035] (1) The oxygen evolution electrode catalyst provided by this invention has a special nanosheet array structure, exhibiting excellent oxygen evolution performance. Experiments have shown that when this catalyst is used, at 10 mA cm⁻¹... -2 The OER overpotential at current density can be as low as 120mV.

[0036] (2) The preparation method of the oxygen evolution electrode catalyst provided by the present invention is simple, the conditions are mild, the raw materials are readily available, and the equipment requirements are low, making it suitable for large-scale production. Attached Figure Description

[0037] Figure 1 This is a SEM image of the oxygen evolution electrode catalyst A1 obtained in Example 1.

[0038] Figure 2 This is the XRD curve of the oxygen evolution electrode catalyst A1 obtained in Example 1. The horizontal axis of the figure is the XRD scanning angle, and the vertical axis is the diffraction intensity.

[0039] Figure 3This is an EDS image of the oxygen evolution electrode catalyst A1 obtained in Example 1, from the surface to a depth of 1 micrometer. The horizontal axis represents X-ray energy, and the vertical axis represents X-ray count, i.e., intensity value.

[0040] Figure 4 This is an LSV curve of the oxygen evolution electrode catalyst A1 obtained in Example 1. The horizontal axis represents potential (V), and the vertical axis represents current density (A·cm). -2 ).

[0041] Figure 5 This is a SEM image of the oxygen evolution electrode catalyst A3 obtained in Example 3.

[0042] Figure 6 This is a SEM image of the oxygen evolution electrode catalyst A8 obtained in Comparative Example 1. Detailed Implementation

[0043] The present invention will now be described in detail with reference to specific embodiments and accompanying drawings. It should be noted that the following embodiments are only used to further illustrate the present invention and should not be construed as limiting the scope of protection of the present invention. Some non-essential improvements and adjustments made by those skilled in the art based on the content of the present invention are still within the scope of protection of the present invention.

[0044] The endpoints and any values ​​of the ranges disclosed herein are not limited to the precise ranges or values, and these ranges or values ​​should be understood to include values ​​close to these ranges or values. For numerical ranges, the endpoint values ​​of the various ranges, the endpoint values ​​of the various ranges and individual point values, and individual point values ​​can be combined with each other to obtain one or more new numerical ranges, which should be considered as specifically disclosed herein.

[0045] Unless otherwise specified, all reagents used in the following examples were commercially available products purchased from reputable chemical suppliers and were of analytical purity; the nickel foam was purchased from Kunshan Guangjiayuan New Materials Co., Ltd.

[0046] Unless otherwise specified, the operating temperature in the following embodiments is room temperature (25±5℃).

[0047] In the following examples, M represents mol / L.

[0048] In the following examples, the surface morphology of the catalyst was characterized by analysis using an XL-30 field emission environmental scanning electron microscope from FEI Corporation, USA; the quantitative analysis of the active substances on the catalyst surface (molar ratio of Ni to NiO) was performed using an Apollo XP energy-dispersive spectrometer from EDAX Corporation, USA; and the structure of the catalyst was determined by X-ray diffraction (XRD) using a D8 Advance X-ray diffractometer from Bruker AXS Corporation, Germany, with CuKa rays, 2θ = 10°–80°, and a step size of 0.02° / min.

[0049] Example 1

[0050] The oxygen evolution electrode catalyst (water electrolysis catalyst) was prepared using the following method:

[0051] (1) Take a piece of nickel foam with a length × width of 5cm × 3cm (thickness 0.5mm, porosity 85%), first immerse it in ethanol and ultrasonically clean it for 30min, then take it out and immerse it in 1M sulfuric acid solution and ultrasonically clean it for 10min, and then dry it to obtain clean nickel foam.

[0052] (2) Prepare 60 mL of potassium nitrate aqueous solution (containing 0.05 g of potassium nitrate) to obtain the reaction solution;

[0053] (3) The clean nickel foam was completely immersed in the above reaction solution and reacted at 90°C for 8 hours. After the reaction was completed, the nickel foam was removed, washed with deionized water, and dried at 40°C for 5 hours to obtain oxygen evolution electrode catalyst A1. Figure 1 This is a SEM image of the oxygen evolution electrode catalyst A1 obtained in Example 1. Figure 1 It can be seen that the oxygen evolution electrode catalyst A1 has a nanosheet array grown in situ perpendicular to the substrate surface on nickel foam, and the thickness of the nanosheet is 11-12 nm. Figure 2 This is the XRD pattern of the oxygen evolution electrode catalyst A1 obtained in Example 1. Figure 2 It can be seen that the oxygen evolution electrode catalyst A1 is a composite material of Ni and NiO; Figure 3 This is an EDS image of the oxygen evolution electrode catalyst A1 obtained in Example 1, from its surface to a depth of 1 micrometer. Figure 3 It can be seen that the nanosheet array of oxygen evolution electrode catalyst A1 contains Ni and O elements, that is, it contains NiO. From the surface to a depth of 1 micrometer, the atomic percentage of Ni element in oxygen evolution electrode catalyst A1 is 61.47%, the atomic percentage of O element is 16.27%, and the atomic percentage of C element is 22.26%, that is, the molar ratio of Ni to NiO is 2.8:1.

[0054] Example 2

[0055] The method described in Example 1 was used, except that the reaction solution was 60 mL of sodium nitrate aqueous solution (containing 0.04 g of sodium nitrate). All other operations and conditions were the same as in Example 1 to obtain oxygen evolution electrode catalyst A2. Oxygen evolution electrode catalyst A2 was prepared by in-situ growth of a nanosheet array perpendicular to the substrate surface on a nickel foam substrate. The nanosheets had a thickness of 14-15 nm. The nanosheet array of oxygen evolution electrode catalyst A2 contained Ni and O elements, i.e., NiO. The molar ratio of Ni to NiO in oxygen evolution electrode catalyst A2 from the surface to a depth of 1 micrometer was 3.2:1.

[0056] Example 3

[0057] The method described in Example 1 was used, except that the reaction solution was 60 mL of sodium nitrate aqueous solution (containing 0.035 g of sodium nitrate). All other operations and conditions were the same as in Example 1, resulting in oxygen evolution electrode catalyst A3. Oxygen evolution electrode catalyst A3 was prepared by in-situ growth of a nanosheet array perpendicular to the substrate surface on a nickel foam substrate. The nanosheets had a thickness of 12-14 nm. The nanosheet array of oxygen evolution electrode catalyst A3 contained Ni and O elements, i.e., NiO. The molar ratio of Ni to NiO in oxygen evolution electrode catalyst A3 from the surface to a depth of 1 micrometer was 3.5:1.

[0058] Example 4

[0059] The method described in Example 1 was used, except that the thickness of the nickel foam was 1.8 mm, and the reaction solution was 60 mL of potassium nitrate aqueous solution (containing 0.08 g of potassium nitrate). All other operations and conditions were the same as in Example 1, resulting in oxygen evolution electrode catalyst A4. Oxygen evolution electrode catalyst A4 was prepared by in-situ growth of a nanosheet array perpendicular to the substrate surface on a nickel foam substrate. The nanosheets had a thickness of 11-13 nm. The nanosheet array of oxygen evolution electrode catalyst A4 contained Ni and O elements, i.e., NiO. The molar ratio of Ni to NiO in oxygen evolution electrode catalyst A4 from the surface to a depth of 1 micrometer was 2.5:1.

[0060] Example 5

[0061] The method described in Example 1 was used, except that clean nickel foam was completely immersed in the reaction solution and reacted at 120°C for 10 hours. All other operations and conditions were the same as in Example 1, resulting in oxygen evolution electrode catalyst A5. Oxygen evolution electrode catalyst A5 was prepared by growing an array of nanosheets perpendicularly to the substrate surface in situ on a nickel foam substrate. The thickness of the nanosheets was 13-16 nm. The nanosheet array of oxygen evolution electrode catalyst A5 contained Ni and O elements, i.e., NiO. The molar ratio of Ni to NiO in oxygen evolution electrode catalyst A5 from the surface to a depth of 1 micrometer was 2.4:1.

[0062] Example 6

[0063] The method described in Example 1 was used, except that the reaction solution was 60 mL of potassium nitrate aqueous solution (containing 0.2 g of potassium nitrate). All other operations and conditions were the same as in Example 1, resulting in oxygen evolution electrode catalyst A6. Oxygen evolution electrode catalyst A6 was prepared by in-situ growth of a nanosheet array perpendicular to the substrate surface on a nickel foam substrate. The nanosheets had a thickness of 17-20 nm. The nanosheet array of oxygen evolution electrode catalyst A6 contained Ni and O elements, i.e., NiO. The molar ratio of Ni to NiO in oxygen evolution electrode catalyst A6 from the surface to a depth of 1 micrometer was 2.1:1.

[0064] Example 7

[0065] Using the method described in Example 1, except that a 5 mm thick nickel foam (with unchanged pore size and porosity) was used as the support material, all other operations and conditions were the same as in Example 1, to obtain oxygen evolution electrode catalyst A7. Oxygen evolution electrode catalyst A7 has a nanosheet array grown in situ perpendicular to the substrate surface on a nickel foam substrate. The nanosheets are 24-26 nm thick. The nanosheet array of oxygen evolution electrode catalyst A7 contains Ni and O elements, i.e., it contains NiO. The molar ratio of Ni to NiO in oxygen evolution electrode catalyst A7 from the surface to a depth of 1 micrometer is 3.9:1.

[0066] Comparative Example 1

[0067] The method in Example 1 was used, except that Ni powder of the same mass as that in Example 1 was used instead of nickel foam in Example 1, and all other operations and conditions were the same as in Example 1, to obtain oxygen evolution electrode catalyst A8. Figure 6 This is a SEM image of the oxygen evolution electrode catalyst A8 obtained in Comparative Example 1. Figure 6 It can be seen that the oxygen evolution electrode catalyst A8 is granular with a particle size of about 200 nm.

[0068] Test Example 1

[0069] Scanning electron microscopy was used to observe the catalysts obtained in the above examples and comparative examples, and it was found that catalysts A1-A7 all possess a unique nanosheet array structure. Figure 1 The SEM image of A1 is shown as an example. Figure 5 The example shown is the SEM image of A3; the SEM images of A2, A4-A7 are similar.

[0070] Test Example 2

[0071] Using the catalysts prepared in the above examples and comparative examples as the working electrode, a graphite rod as the counter electrode, and a standard hydrogen electrode as the reference electrode, a three-electrode system was constructed using 1M KOH solution as the electrolyte. The OER performance of the catalysts was then tested. The specific method is as follows:

[0072] Electrochemical testing was conducted using a Shanghai Chenhua 760E electrochemical workstation. Before testing, N2 was passed through the electrolyte for approximately 30 minutes to saturate it. Then, the three-electrode testing system was assembled, with the voltage range set to 0 to 1.2V (vs. RHE) and the number of test cycles set to 20 to ensure complete sample activation and exposure of active sites. Next, H2 was passed through the electrolyte using a hydrogen generator for 30 minutes to completely saturate it. LSV testing was then performed at 1.2 to 1.8V. 1M KOH was used as the electrolyte at 10mA·cm⁻¹. -2 and 100mA·cm -2 The OER overpotential of the catalyst was detected at the current density. The test data are shown in Table 1.

[0073] Table 1

[0074]

[0075] As can be seen from Example 1, Comparative Example 1 and Table 1, compared with powdered elemental nickel, the oxygen evolution electrode catalyst prepared by reacting sheet-like foamed nickel with nitrate solution in this invention has a significantly lower overpotential and higher catalytic activity.

[0076] As can be seen from Examples 1-7 and Table 1, the oxygen evolution electrode catalyst prepared by the preparation method of the present invention has a special nanosheet array structure. Through ultrathinning and heterogeneous composite, the active sites of the catalyst are significantly increased, thus exhibiting excellent oxygen evolution performance.

[0077] It should be noted that the embodiments described above are only for explaining the present invention and do not constitute any limitation on the present invention. The present invention has been described with reference to typical embodiments, but it should be understood that the words used therein are descriptive and explanatory terms, not limiting terms. Modifications can be made to the present invention within the scope of the claims, and revisions can be made to the present invention without departing from the scope and spirit of the present invention. Although the present invention described herein relates to specific methods, materials, and embodiments, it does not mean that the present invention is limited to the specific examples disclosed herein; on the contrary, the present invention can be extended to all other methods and applications with the same function.

[0078] All publications, patent applications, patents, and other references mentioned in this specification are incorporated herein by reference. Unless otherwise defined, all technical and scientific terms used in this specification have the meanings commonly understood by those skilled in the art. In case of conflict, the definitions in this specification shall prevail.

[0079] When this specification uses the prefixes “known to those skilled in the art,” “prior art,” or similar terms to derive materials, substances, methods, steps, apparatus, or components, the objects derived from such prefixes cover those commonly used in the art at the time of this application, but also include those that are not currently commonly used but will become generally recognized in the art as suitable for similar purposes.

[0080] The endpoints and any values ​​of the ranges disclosed in this application are not limited to the precise ranges or values; such ranges or values ​​should be understood to include values ​​close to them. For numerical ranges, the endpoint values ​​of the various ranges, the endpoint values ​​of the various ranges and individual point values, and individual point values ​​can be combined with each other to obtain one or more new numerical ranges, which should be considered as specifically disclosed herein. In principle, various technical solutions can be combined with each other to obtain new technical solutions, which should also be considered as specifically disclosed herein.

[0081] In the context of this specification, except where expressly stated otherwise, any matters or issues not mentioned shall apply directly to those known in the art without any modification.

[0082] Furthermore, any implementation described herein can be freely combined with one or more other implementations described herein, and the resulting technical solutions or technical ideas shall be regarded as part of the original disclosure or original record of the present invention, and should not be regarded as new content not disclosed or anticipated herein, unless those skilled in the art believe that the combination is obviously unreasonable.

Claims

1. A water electrolysis catalyst, comprising a substrate made of nickel foam and an array of nickel oxide nanosheets perpendicular to the surface of the substrate.

2. The water electrolysis catalyst as described in claim 1, characterized in that: The thickness of the nanosheet is 5-30 nm, preferably 8-20 nm, and more preferably 10-16 nm; and / or, The thickness of the substrate is 0.2-6 mm, preferably 0.5-3 mm, and more preferably 0.5-2 mm.

3. A method for preparing a water electrolysis catalyst, preferably the method for preparing the water electrolysis catalyst according to any one of claims 1-2, comprising the step of reacting nickel foam with a nitrate solution.

4. The preparation method according to claim 3, characterized in that: The nickel foam is in sheet form with a thickness of 0.2-6 mm, preferably 0.5-3 mm, more preferably 0.5-2 mm; and / or, the porosity of the nickel foam is 60-95%, preferably 80-95%, more preferably 80-90%.

5. The preparation method according to claim 3, characterized in that: The nitrate is selected from at least one alkali metal nitrate, preferably from at least one of potassium nitrate and sodium nitrate; and / or, The nitrate solution is an aqueous nitrate solution. Preferably, the concentration of the aqueous nitrate solution is 0.1-5 g / L, more preferably 0.3-2.5 g / L, and even more preferably 0.5-1.5 g / L.

6. The preparation method according to claim 3, characterized in that: The volume ratio of the nickel foam to the nitrate solution is 1:(50-150), preferably 1:(70-90).

7. The preparation method according to claim 3, characterized in that: The reaction conditions include: a reaction temperature of 80-150℃, preferably 90-120℃; and / or a reaction time of 6-15h, preferably 8-12h.

8. The preparation method according to any one of claims 3-7, characterized in that: The nickel foam further includes a first cleaning step before reacting with the nitrate solution; preferably, The first cleaning includes the steps of sequentially cleaning the nickel foam with an organic solvent and an inorganic acid solution; more preferably, The organic solvent is selected from at least one of organic solvents with ≤5 carbon atoms, preferably at least one of ethanol and acetone; and / or, The inorganic acid solution is selected from at least one aqueous solution of sulfuric acid, hydrochloric acid, and nitric acid, preferably containing H+. + The concentration shall not exceed 3M, more preferably 0.5-2M; and / or, The first cleaning is performed under ultrasonic conditions, preferably by ultrasonication in the organic solvent and inorganic acid solution for 5-60 min each, more preferably 10-40 min.

9. The preparation method according to any one of claims 3-7, characterized in that: After the reaction between the nickel foam and the nitrate solution is completed, a second cleaning step is also included; preferably, The second cleaning includes rinsing with water and / or an organic solvent; and / or, After the second cleaning, a drying step is also included; more preferably, The drying conditions include: a drying temperature of 20-60℃ and / or a drying time of 4-12 hours.

10. A method for producing hydrogen by electrolysis of water, wherein the water electrolysis catalyst according to any one of claims 1-2 or the water electrolysis catalyst obtained by any one of the preparation methods according to claims 3-9 is used as the oxygen evolution electrode catalyst for producing hydrogen by electrolysis of water.

11. The application of a water electrolysis catalyst as described in any one of claims 1-2, or a water electrolysis catalyst obtained by any one of claims 3-9, or a method as described in claim 10, in the field of hydrogen production by water electrolysis.

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