Self-supporting hydrogen evolution electrode for alkaline electrolysis of water with gradient pore structure, and preparation method and application thereof

Abstract

The present application relates to a kind of gradient hole structure's self-supporting alkaline electrolytic water hydrogen production electrode and its preparation method and application, wherein the preparation method includes: A) in two electrode system, two nickel iron metal salt containing different gas production additive concentration are used as electroplating solution, nickel mesh is used as working electrode, platinum sheet is used as counter electrode, electrodeposition is carried out in two kinds of electroplating solution in turn, and make that electrodeposition is while current density is uniformly increased, obtain the nickel mesh material of gradient porous nickel iron alloy deposition layer supported;B) the nickel mesh material obtained in step A is washed, dried, and the gradient hole structure's self-supporting alkaline electrolytic water hydrogen production electrode is obtained.Compared with prior art, the gradient porous nickel iron deposition layer of composite on nickel mesh substrate material is prepared using electrodeposition method in the present application, and gradient porous structure greatly improves the real surface area of electrode, and promotes bubble discharge simultaneously.

Description

Technical Field

[0001] This invention relates to the field of water electrolysis for hydrogen production technology, and in particular to a self-supporting alkaline water electrolysis electrode with a gradient pore structure, its preparation method, and its application. Background Technology

[0002] Over-reliance on fossil fuels has led to the dual problems of energy shortages and environmental pollution. Researchers worldwide are currently dedicated to finding a renewable and pollution-free clean energy source. With my country's renewable energy resources, primarily wind and solar power, becoming increasingly abundant, hydrogen production through water electrolysis is gaining favor among scientists. Hydrogen energy boasts advantages such as cleanliness and high energy density, making it the most promising energy carrier for the future and gradually replacing fossil fuels as the primary energy source for future society. However, in the process of hydrogen production through water electrolysis, the oxygen evolution reaction, with its high overpotential and slow kinetics, has consistently been a bottleneck limiting the energy conversion efficiency of the entire water electrolysis system. A well-designed catalytic electrode can significantly reduce energy loss and improve the efficiency of the water electrolysis reaction.

[0003] Porous structures are a common design approach to increase the active surface area of ​​electrodes. Currently, a method for preparing porous electrodes using electrodeposition technology is widely used. This method involves adding ammonium ions to the electrodeposition solution, causing hydrogen gas to be generated simultaneously with the deposition of the metal electrode structure, ultimately leaving naturally formed pores in the formed electrode. Because this electrode preparation environment is similar to the actual working environment of OER (Oil Erector Deposition), it can better adapt to the gas exhaust conditions under actual operating conditions, exhibiting low mass transport loss. Furthermore, this one-step method for preparing porous electrodes using electrodeposition technology is simple to operate and easy to scale up, making it very suitable for industrial production. However, in actual characterization, its OER performance still lags behind some electrode structures with high active surface areas, failing to reach a satisfactory level.

[0004] Considering this electrode structure that allows for the natural expulsion of bubbles, it already exhibits sufficiently low loss in mass transfer. However, because the pores generated by the bubbles are macroscopic, although they create a porous structure visible to the naked eye, the reaction surface area remains small under microscopic conditions. This affects the kinetic performance of the electrode, which is the main reason for its insufficient OER performance.

[0005] To address the aforementioned issues, there is an urgent need to improve a new method for preparing porous electrodes so that it can achieve the required high active surface area while conforming to the bubble discharge path. Summary of the Invention

[0006] The purpose of this invention is to overcome the shortcomings of current self-supporting electrodes for alkaline water electrolysis hydrogen production, such as small specific surface area, few active sites, and low mass transfer efficiency. A gradient porous nickel-iron deposition layer composite on a nickel mesh substrate is prepared using an electrodeposition method. The gradient porous structure greatly improves the actual surface area of ​​the electrode and promotes the expulsion of bubbles.

[0007] The objective of this invention can be achieved through the following technical solutions:

[0008] The first aspect of this invention provides a method for preparing a self-supporting alkaline water electrolysis hydrogen production electrode with a gradient pore structure, comprising the following steps:

[0009] A) In a two-electrode system, two aqueous solutions of nickel-iron metal salts with different concentrations of gas-generating additives are used as electroplating solutions. A nickel mesh is used as the working electrode and a platinum sheet is used as the counter electrode. Electrodeposition is carried out sequentially in the two electroplating solutions, and the current density is increased uniformly during the electrodeposition to obtain a nickel mesh material with a load gradient porous nickel-iron alloy deposition layer.

[0010] B) The nickel mesh material obtained in step A is cleaned and dried to obtain a self-supporting alkaline water electrolysis hydrogen production electrode with a gradient pore structure.

[0011] Furthermore, in step A), the nickel mesh is a pretreated nickel mesh;

[0012] The nickel wire diameter of the nickel mesh is 50-300 μm, and the mesh size of the nickel mesh is 50-400 mesh.

[0013] Further, in step A), the pretreatment process of the nickel mesh is as follows: the nickel mesh is first ultrasonically treated in dilute hydrochloric acid, then ultrasonically treated in anhydrous ethanol, then ultrasonically treated in deionized water, and finally naturally dried.

[0014] Further, in step A), the electroplating solution comprises a combination of the following two electroplating solutions:

[0015] Electroplating solution a) The concentration of nickel chloride is 0.6-1.0 mol / L, the concentration of ferrous chloride is 0.1-0.3 mol / L, and the concentration of gas-generating additive ammonium chloride is 0.6-1.4 mol / L;

[0016] Electroplating solution b): The concentration of nickel chloride is 0.6-1.0 mol / L, the concentration of ferrous chloride is 0.1-0.3 mol / L, and the concentration of gas-generating additive ammonium chloride is 1.6-2.4 mol / L.

[0017] Further, in step A), the electroplating solution comprises a combination of the following two electroplating solutions:

[0018] Electroplating solution a): The concentration of nickel chloride is 0.8 mol / L, the concentration of ferrous chloride is 0.2 mol / L, and the concentration of gas-generating additive ammonium chloride is 1.0 mol / L;

[0019] Electroplating solution b): The concentration of nickel chloride is 0.8 mol / L, the concentration of ferrous chloride is 0.2 mol / L, and the concentration of gas-generating additive ammonium chloride is 2.0 mol / L.

[0020] Further, in step A), the electrodeposition time is 10 minutes, and the current density uniformly increases from 1 A / cm² within 10 minutes. 2 Increased to 3A / cm 2 The electrodeposition temperature is 20–30℃.

[0021] Further, in step A), the cleaning process involves first rinsing the surface impurities with deionized water, then rinsing with anhydrous ethanol, and the drying temperature is room temperature.

[0022] A second aspect of the present invention provides a self-supporting alkaline water electrolysis hydrogen production electrode prepared by the above method, the self-supporting alkaline water electrolysis hydrogen production electrode comprising: a nickel mesh substrate material and a gradient porous nickel-iron deposition layer composite on the nickel mesh substrate material;

[0023] In the gradient porous nickel-iron deposition layer: the inner layer is a porous structure with a smaller diameter and a greater number of pores, which has a larger actual surface area and reactive sites, while the outer layer is a porous structure with a larger diameter, which has a better ability to expel bubbles.

[0024] Furthermore, the gradient porous nickel-iron deposition layer is: a gradient porous nickel-iron deposition layer electrodeposited on the nickel mesh substrate material by changing the current density and the concentration of the gas-generating additive;

[0025] The diameter of the internal pores in the gradient porous nickel-iron deposition layer is 1–5 μm, and the diameter of the external pores is 20–40 μm.

[0026] A third aspect of the present invention provides an application of the self-supporting alkaline water electrolysis hydrogen production electrode as described above in water electrolysis hydrogen production.

[0027] The main conceptual principle of this invention is as follows:

[0028] In this invention, the nickel mesh deposited in step A) forms a distinct gradient porous structure, with the pore size gradually increasing as the electrode thickness increases. The pores on the electrode side are small and dense, providing a larger reactive surface area, thus exhibiting lower overpotential and faster reaction rates under the high current density of industrial water electrolysis. The pores on the solution side are larger and looser, facilitating bubble removal and preventing significant losses due to excessive bubble blockage of the electrode surface. Therefore, the gradient porous structure self-supporting electrode provided by this invention can be used for alkaline water electrolysis to produce hydrogen, exhibiting good catalytic activity and mass transport capabilities.

[0029] Compared with the prior art, the present invention has the following technical advantages:

[0030] Compared to existing electrode preparation methods, this invention employs electrodeposition technology, which is highly suitable for large-scale industrial production and is simple, easy to control, and inexpensive. By gradient-adjusting parameters such as the concentration of gas-generating additives and current density, this invention alters the size of the pores formed under different operating conditions, creating a gradient change in pore size. This results in a morphological characteristic where the pores are small and dense near the electrode and large and loose near the solution. Compared to existing porous electrodes, this gradient porous structure has a larger reaction area on the electrode side, thus exhibiting better kinetic performance, and more porous pores on the solution side, thus facilitating bubble expulsion. In summary, the porous electrode proposed in this invention has higher OER performance, significantly improving the economic efficiency of industrial water electrolysis. Attached Figure Description

[0031] Figure 1 This is a preprocessed NM microscope image from Embodiment 1 of the present invention;

[0032] Figure 2 This is a microscope image of the non-gradient deposited PN / NM in Application Example 1 of the present invention;

[0033] Figure 3 These are microscope images of PNout / PNin / NM deposited using gradient deposition in Example 1 of this invention;

[0034] Figure 4 The current-voltage scan curve is shown for the oxygen evolution reaction in Application Example 1 of this invention. Detailed Implementation

[0035] This invention proposes a self-supporting alkaline water electrolysis hydrogen production electrode with a gradient pore structure, comprising:

[0036] Nickel mesh substrate material;

[0037] A gradient porous nickel-iron deposition layer composited on the nickel mesh substrate material;

[0038] Specifically, including:

[0039] Nickel mesh substrate material;

[0040] A gradient porous nickel-iron deposition layer was electrodeposited on the nickel mesh substrate by varying the current density and the concentration of the gas-generating additive.

[0041] In an embodiment of the present invention, the gradient porous nickel-iron deposition layer has an internal pore diameter of 1–5 μm and an external pore diameter of 20–40 μm.

[0042] This invention also provides a method for preparing a self-supporting alkaline water electrolysis hydrogen production electrode with a gradient pore structure as described above, comprising the following steps:

[0043] A) In a two-electrode system, nickel-iron metal salts with different concentrations of gas-generating additives are used as electroplating solutions, with nickel mesh as the working electrode and platinum sheet as the counter electrode. Electrodeposition is carried out sequentially in the two electroplating solutions (the current density is also increasing uniformly during the electrodeposition) to obtain a nickel mesh material with a load gradient porous nickel-iron alloy deposition layer.

[0044] B) Clean and dry the material obtained in step A.

[0045] In some embodiments of the present invention, the nickel mesh is a pretreated nickel mesh. The pretreated nickel mesh is prepared according to the following method:

[0046] The nickel mesh was ultrasonically treated in dilute hydrochloric acid to remove surface oxides, then ultrasonically treated in anhydrous ethanol to remove hydrochloric acid and organic matter from the surface, and finally ultrasonically treated in deionized water to remove other residual impurities from the surface.

[0047] In some embodiments of the present invention, the concentration of the dilute hydrochloric acid is 0.5–1.2 mol / L; specifically, it can be 1 mol / L. The ultrasonic treatment time is 15 min.

[0048] In this invention, in a two-electrode system, nickel-iron metal salts with different concentrations of gas-generating additives are used as electroplating solutions, nickel mesh is used as the working electrode and platinum sheet is used as the counter electrode. After applying current, while nickel metal is being electrodeposited, hydrogen evolution side reaction occurs at the cathode and bubbles are generated, resulting in a nickel mesh material with a load gradient porous nickel-iron alloy deposition layer.

[0049] In some embodiments of the present invention, the nickel-iron metal salt electroplating solution includes nickel chloride, ferrous chloride, ammonium chloride and deionized water;

[0050] In the nickel-iron metal salt electroplating solution a), the concentration of nickel chloride is 0.6–1.0 mol / L, the concentration of ferrous chloride is 0.1–0.3 mol / L, and the concentration of the gas-generating additive ammonium chloride is 0.6–1.4 mol / L; specifically, in the nickel-iron metal salt electroplating solution a), the concentration of nickel chloride can be 0.8 mol / L, the concentration of ferrous chloride can be 0.2 mol / L, and the concentration of the gas-generating additive ammonium chloride can be 1.0 mol / L.

[0051] In the nickel-iron metal salt electroplating solution b), the concentration of nickel chloride is 0.6–1.0 mol / L, the concentration of ferrous chloride is 0.1–0.3 mol / L, and the concentration of the gas-generating additive ammonium chloride is 1.6–2.4 mol / L; specifically, in the nickel-iron metal salt electroplating solution b), the concentration of nickel chloride can be 0.8 mol / L, the concentration of ferrous chloride can be 0.2 mol / L, and the concentration of the gas-generating additive ammonium chloride can be 2.0 mol / L.

[0052] In some embodiments of the present invention, the electrodeposition is performed in a deposition tank. The electrodeposition time is 10 minutes, and the current density uniformly increases from 1 A / cm² within 10 minutes. 2 Increased to 3A / cm 2 The temperature is 20-30℃; specifically, the temperature can be 25℃.

[0053] In some embodiments of the present invention, after electrodeposition, the process further includes washing and drying; specifically, this includes rinsing the electrodeposited composite material with deionized water, then rinsing with anhydrous ethanol, and then air drying. The number of rinsing cycles can be 3 to 5 times; specifically, 3 times. Each rinsing cycle lasts 10 to 30 seconds; specifically, 20 seconds. The water flow rate during rinsing should be gentle and should not damage the electrodeposited structure.

[0054] The present invention also provides an application of a self-supporting electrode with a gradient pore structure in water electrolysis for hydrogen production. Specifically, the present invention also provides an application of a self-supporting alkaline water electrolysis hydrogen production electrode with a gradient pore structure as a catalyst for water electrolysis hydrogen production.

[0055] This invention uses a nickel mesh as the substrate material and prepares a gradient porous nickel-iron deposition layer composite on the nickel mesh substrate material using an electrodeposition method. The gradient porous structure greatly increases the actual surface area of ​​the electrode and promotes the removal of air bubbles.

[0056] This invention uses a two-step electrodeposition method to form a gradient porous structure. The inner layer is a porous structure with a smaller diameter and a greater number of pores, resulting in a larger actual surface area and more reactive sites; the outer layer is a porous structure with a larger diameter, providing better bubble expulsion capability.

[0057] This invention uses an electrodeposition process, eliminating the need for traditional etching or chemical deposition processes, simplifying operation, improving production efficiency, and making it suitable for large-scale industrial production.

[0058] The present invention does not impose any special restrictions on the source of the raw materials used above, and they can be commercially available.

[0059] To further illustrate the present invention, the following detailed description, in conjunction with embodiments, describes a self-supporting alkaline water electrolysis hydrogen production electrode with a gradient pore structure, its preparation method, and its application, but this should not be construed as limiting the scope of protection of the present invention.

[0060] All reagents used in the following examples are commercially available. Any preparation methods, materials, structures, or composition ratios not explicitly described in this technical solution are considered common technical features disclosed in the prior art.

[0061] Example 1

[0062] The preparation method of the self-supporting alkaline water electrolysis hydrogen production electrode with gradient pore structure in this embodiment includes the following steps:

[0063] 1) Pretreatment of nickel mesh:

[0064] The nickel mesh was ultrasonically treated in 1 mol / L dilute hydrochloric acid to remove surface oxides, then ultrasonically treated in anhydrous ethanol to remove hydrochloric acid and organic matter from the surface, and finally ultrasonically treated in deionized water to remove other residual impurities from the surface, resulting in a pretreated nickel mesh (named NM).

[0065] 2) Preparation of nickel mesh material for a load-gradient porous nickel-iron deposition layer:

[0066] Nickel-iron metal salt electroplating solution includes nickel chloride, ferrous chloride, ammonium chloride, and deionized water;

[0067] In the nickel-iron metal salt electroplating solution a), the concentration of nickel chloride is 0.8 mol / L, the concentration of ferrous chloride is 0.2 mol / L, and the concentration of the gas-generating additive ammonium chloride is 1.0 mol / L.

[0068] In nickel-iron metal salt electroplating solution b), the concentration of nickel chloride is 0.8 mol / L, the concentration of ferrous chloride is 0.2 mol / L, and the concentration of gas-generating additive ammonium chloride is 2.0 mol / L.

[0069] In the two-electrode system, the deposition tank contains the nickel-iron metal salt electroplating solution prepared in the above steps. A pretreated nickel mesh is used as the working electrode, and a platinum sheet as the counter electrode. A current is applied (current density: uniformly increasing from 1 A / cm² within 10 min). 2 Increased to 3A / cm 2The nickel mesh material (named PN) was deposited sequentially in electroplating solutions a) and b) for 5 minutes each, thereby obtaining a nickel-iron deposited layer with a loading gradient porous structure. out / PN in / NM). The obtained composite material was removed from the deposition tank, cleaned with deionized water and anhydrous ethanol, and then air-dried.

[0070] Figure 1 This is a preprocessed NM microscope image from Embodiment 1 of the present invention;

[0071] Figure 2 This is a microscope image of the non-gradient deposited PN / NM in Application Example 1 of the present invention;

[0072] Figure 3 The PN deposited by gradient deposition in Example 1 of this invention out / PN in Microscopic images of / NM;

[0073] Depend on Figure 1 and Figure 2 , 3 It can be seen that, through the electrodeposition process, a porous nickel-iron deposition layer is formed on the surface of the nickel mesh. Figure 1 Compared to the smooth surface of a nickel mesh, the electrodeposition process roughens the surface of the nickel mesh, increasing the actual surface area of ​​the nickel mesh.

[0074] Depend on Figure 2 and Figure 3 It can be seen that porous structures formed by gradient deposition ( Figure 3 The deposit exhibits a gradient structure with small internal pores and large external pores, with one or more small pores of significantly different sizes visible at the bottom of the large pores. This is because three gas-generating additive solutions of different concentrations were used sequentially during the electrodeposition process. Initially, in the low-concentration gas-generating additive solution, smaller pores were formed at the bottom of the deposit. Subsequently, when the solution with a higher concentration of gas-generating additive was used, even larger pores were generated on top of the existing pores, thus forming a layered gradient pore structure, rather than a gradient deposition porous structure. Figure 2 There was no obvious change in pore size; it only showed cylindrical-shaped pores. This indicates that a porous structure with two different pore size properties was generated through the gradient deposition process.

[0075] Application Example 1

[0076] A standard three-electrode system was used, with mercury / mercury oxide (Hg / HgO) as the reference electrode, 2×2cm. 2 The platinum sheet is used as the counter electrode, 1*1cm 2 The electrode PN prepared in Example 1 out / PN in / NM was used as the working electrode. Electrochemical tests were performed on a Corrtest electrochemical workstation using a 1 mol / L KOH solution as the electrolyte and the test temperature was controlled at 25℃ to carry out the oxygen evolution reaction.

[0077] Electrode preparation for control group 2: In the two-electrode system, a nickel-iron metal salt was used as the electroplating solution, with a nickel mesh as the working electrode and a platinum sheet as the counter electrode for electrodeposition, to obtain a nickel mesh material with a porous nickel-iron alloy deposition layer. In the nickel-iron metal salt solution, the concentrations of other components were the same as in the preparation process, except that the concentration of the gas-generating additive was taken as the average value of 1.5 mol / L; the electrodeposition current density was taken as the average value of 2 A / cm² in the preparation process. 2 Apart from the above, the other operations are the same as the preparation process. This process yields a non-gradient porous nickel-iron deposited layer (named PN / NM).

[0078] Set up control group 1, using NM from Example 1 as the working electrode, and the rest of the operation is the same as the above steps;

[0079] Control group 2 was set up, using PN / NM from application example 1 as the working electrode, and the remaining operations were the same as the steps above.

[0080] Linear scan Fu'an curve test: The scan rate was 5 mV / s, and the electrode potentials were all compensated with 90% iR and converted into electrode potentials relative to the reversible hydrogen potential (RHE). The calculation formula is shown in equation (*):

[0081] Overpotential (V) = Electrode potential + 0.059 × pH + Hg / HgO electrode potential - 1.23 (*)

[0082] In the formula (*), pH is the pH value of the electrolyte.

[0083] Figure 4 The current-voltage scan curves for the oxygen evolution reaction in Application Example 1 of this invention are shown in the test results.

[0084] Undeposited nickel meshes exhibit poor OER (Oil Efficiency and Residue) performance. Depositing a porous nickel-iron alloy onto the nickel mesh partially improves its OER performance. Replacing the porous nickel-iron alloy with a gradient-deposited porous nickel-iron alloy results in even higher OER performance. It can be seen that the PN (Polynitronic Aluminum) prepared in this invention… out / PN in / NM maintains low overpotential and excellent OER performance even at high current densities.

[0085] Therefore, in this invention, a gradient nickel-iron porous deposition layer is formed on the surface of a nickel mesh using a gradient electrodeposition method. This gradient porous structure has a larger reaction area on the electrode side, resulting in better kinetic performance, and more porous structure on the solution side, which is more conducive to bubble removal. In summary, the gradient porous electrode proposed in this invention exhibits higher OER catalytic performance.

[0086] The above description of the embodiments is provided to enable those skilled in the art to understand and use the invention. It will be apparent to those skilled in the art that various modifications can be made to these embodiments, and the general principles described herein can be applied to other embodiments without inventive effort. Therefore, the present invention is not limited to the above embodiments, and any improvements and modifications made by those skilled in the art based on the disclosure of the present invention without departing from the scope of the invention should be within the protection scope of the present invention.

Claims

1. A method for preparing a self-supporting alkaline water electrolysis hydrogen production electrode with a gradient pore structure, characterized in that, Includes the following steps: A) In a two-electrode system, two aqueous solutions of nickel-iron metal salts with different concentrations of gas-generating additives are used as electroplating solutions. A nickel mesh is used as the working electrode and a platinum sheet is used as the counter electrode. Electrodeposition is carried out in electroplating solutions a) and b) in sequence, and the current density is increased uniformly during the electrodeposition to obtain a nickel mesh material with a load gradient porous nickel-iron alloy deposition layer. B) The nickel mesh material obtained in step A is cleaned and dried to obtain a self-supporting alkaline water electrolysis hydrogen production electrode with a gradient pore structure; In step A), Electroplating solution a): The concentration of nickel chloride is 0.6~1.0 mol / L, the concentration of ferrous chloride is 0.1~0.3 mol / L, and the concentration of gas-generating additive ammonium chloride is 0.6~1.4 mol / L; Electroplating solution b): The concentration of nickel chloride is 0.6~1.0 mol / L, the concentration of ferrous chloride is 0.1~0.3 mol / L, and the concentration of gas-generating additive ammonium chloride is 1.6~2.4 mol / L; In step A), the electrodeposition time is 10 minutes, and the current density uniformly increases from 1 A / cm² within 10 minutes. 2 Increased to 3A / cm 2 The electrodeposition temperature is 20~30℃.

2. The method for preparing a self-supporting alkaline water electrolysis hydrogen production electrode with a gradient pore structure according to claim 1, characterized in that, In step A), the nickel mesh is a pretreated nickel mesh; The nickel wire diameter of the nickel mesh is 50~300um, and the mesh count of the nickel mesh is 50~400 mesh.

3. The method for preparing a self-supporting alkaline water electrolysis hydrogen production electrode with a gradient pore structure according to claim 2, characterized in that, In step A), the pretreatment process of the nickel mesh is as follows: the nickel mesh is first ultrasonically treated in dilute hydrochloric acid, then ultrasonically treated in anhydrous ethanol, then ultrasonically treated in deionized water, and finally naturally dried.

4. The method for preparing a self-supporting alkaline water electrolysis hydrogen production electrode with a gradient pore structure according to claim 1, in step A), Electroplating solution a): The concentration of nickel chloride is 0.8 mol / L, the concentration of ferrous chloride is 0.2 mol / L, and the concentration of gas-generating additive ammonium chloride is 1.0 mol / L; Electroplating solution b): The concentration of nickel chloride is 0.8 mol / L, the concentration of ferrous chloride is 0.2 mol / L, and the concentration of gas-generating additive ammonium chloride is 2.0 mol / L.

5. In the preparation method of a self-supporting alkaline water electrolysis hydrogen production electrode with a gradient pore structure according to claim 1, in step B), the cleaning process is to first rinse the surface impurities with deionized water and then rinse with anhydrous ethanol, and the drying temperature is room temperature.

6. A self-supporting alkaline water electrolysis hydrogen production electrode prepared by the method according to any one of claims 1 to 5, characterized in that, The self-supporting alkaline water electrolysis hydrogen production electrode comprises: a nickel mesh substrate material and a gradient porous nickel-iron deposition layer composited on the nickel mesh substrate material; In the gradient porous nickel-iron deposition layer: the inner layer is a porous structure with a smaller diameter and a greater number of pores, which has a larger actual surface area and reactive sites, while the outer layer is a porous structure with a larger diameter, which has a better ability to expel bubbles.

7. The self-supporting alkaline water electrolysis hydrogen production electrode according to claim 6, characterized in that, The gradient porous nickel-iron deposition layer is a gradient porous nickel-iron deposition layer electrodeposited on the nickel mesh substrate by changing the current density and the concentration of the gas-generating additive. The diameter of the internal pores in the gradient porous nickel-iron deposition layer is 1~5 μm, and the diameter of the external pores is 20~40 μm.

8. The application of the self-supporting alkaline water electrolysis hydrogen production electrode as described in claim 6 in water electrolysis hydrogen production.

Images