Self-supporting electrolyzed water catalytic electrode material, preparation method and application of self-supporting electrolyzed water catalytic electrode material

Abstract

The invention belongs to the technical field of electrode materials, and particularly discloses a self-supporting electrolyzed water catalytic electrode material, a preparation method and application thereof, the self-supporting electrolyzed water catalytic electrode material comprises a foamed nickel-molybdenum alloy as a substrate, and the surface of the foamed nickel-molybdenum alloy is covered with a two-dimensional layered nickel-iron metal hydroxide. The nickel-molybdenum alloy self-supporting nickel-iron double-metal hydroxide obtained by the technology is used as a bifunctional catalyst for hydrogen evolution and oxygen evolution reaction in a non-acidic medium. The foamed nickel-molybdenum alloy is used as a raw material of a current collector and a catalytic active site at the same time, a fresh crystal nucleus is formed on the surface of the foamed nickel-molybdenum alloy through one-step ferric ion etching, then the foamed nickel-molybdenum alloy is placed in air, and the catalytic activity of the nickel-molybdenum alloy is improved under the combined action of water and oxygen. The nickel element from the foamed nickel-molybdenum alloy and the adsorbed iron element spontaneously grow on the surface of the nickel-molybdenum alloy to form the layered double-metal hydroxide nanosheet.

Description

Technical Field

[0001] The present invention belongs to the technical field of electrode materials, and in particular relates to a self-supporting water electrolysis catalytic electrode material, a preparation method and an application thereof. Background Art

[0002] Due to the discontinuous and unstable characteristics of energy sources such as solar energy and wind energy, it is difficult to directly integrate them into the power grid, resulting in a low effective utilization rate of renewable energy. Among the many electrochemical energy storage technologies, water electrolysis to produce hydrogen can absorb renewable energy on a large scale and become an important way to absorb renewable energy. With the development of renewable energy such as solar power generation and wind power generation, the continuous decline in electricity prices and the reduction in energy consumption brought about by advances in water electrolysis to produce hydrogen, the cost of renewable energy-driven water electrolysis to produce hydrogen is expected to be comparable to that of fossil fuel reforming to produce hydrogen, making it competitive in the market. Electrocatalytic water splitting to produce hydrogen is considered to be an efficient and green method of hydrogen production. It is a key way to solve global energy problems and reduce carbon emissions. The development of large-scale, high-efficiency, and long-life water electrolysis hydrogen production equipment is of great value in supporting the development of the hydrogen energy industry.

[0003] The high energy consumption and cost of existing water electrolysis hydrogen production processes hinder their large-scale industrial application. Developing highly active hydrogen and oxygen evolution catalysts is an effective way to reduce the energy consumption of water electrolysis. Iridium dioxide and ruthenium dioxide are highly active in the oxygen evolution reaction. However, these metals are rare in the Earth's crust and are expensive, making their widespread application in commercial water electrolysis difficult. Therefore, research and development of low-cost, simple-to-manufacture, and highly active catalytic electrodes for water electrolysis are crucial.

[0004] Traditional powder catalysts coated on the surface of a conductive substrate inevitably increase the interfacial resistance, affecting the electrocatalytic performance. On the other hand, due to the low adhesion between the catalyst and the substrate, the active sites are less exposed, and the adhesive can also degrade due to various factors, leading to uncontrollable side reactions. Self-supporting electrocatalysts have successfully solved the above shortcomings of powder nanocatalysts. The traditional solvothermal method has the disadvantages of using a variety of chemicals, multiple preparation steps, poor process reliability, and the need for a closed environment with high temperature and high pressure in the preparation of self-supporting catalysts. Therefore, it is very important to develop a simple, efficient, and green process for the preparation of nickel-iron layered double hydroxide oxygen evolution electrodes.

[0005] Nickel-iron-based oxygen evolution catalysts (OER) have been demonstrated to be effective in alkaline electrolytes. Ni-Mo-based materials, due to their suitable hydrogen binding energy and good corrosion resistance in the environment, are considered potential alternatives to Pt / C noble metal catalysts in the field of hydrogen evolution reaction catalysis and are expected to become one of the most promising industrial alkaline non-noble metal HER catalysts. Traditional water splitting technology requires the preparation of single-functional bipolar catalysts for hydrogen and oxygen evolution, but suffers from high anode overpotentials and low anode product value. Developing catalytic materials with both hydrogen and oxygen evolution activity and replacing the oxygen evolution process with a thermodynamically favorable reaction to achieve single-catalyst-driven full / composite water splitting can simplify bipolar catalyst preparation, avoid cross-contamination during service, reduce the anode potential, and improve hydrogen production efficiency and electrolysis device safety. Summary of the Invention

[0006] In order to solve the problems existing in the prior art, the present invention provides a self-supporting water electrolysis catalytic electrode material, a preparation method and its application. The nickel-molybdenum alloy self-supporting nickel-iron double metal hydroxide obtained by this technology is used as a bifunctional catalyst for hydrogen and oxygen evolution reactions in non-acidic media.

[0007] The technical solution adopted in the present invention is: In a first aspect, the present invention provides a self-supporting water electrolysis catalytic electrode material, comprising a nickel-molybdenum alloy as a substrate, wherein the surface of the foamed nickel-molybdenum alloy is covered with a two-dimensional layered nickel-iron metal hydroxide.

[0008] In the second aspect, the present invention provides a preparation method for producing a self-supporting electrolytic water catalytic electrode material according to the first aspect above. The foamed nickel-molybdenum alloy material is first pretreated and cleaned, and the treated nickel-molybdenum alloy material is immersed in an etching aqueous solution containing a solute including trivalent iron ions and ethylene glycol for etching. After etching, the material is cleaned and dried in a natural environment to form a nickel-iron metal hydroxide / nickel-molybdenum alloy material.

[0009] In combination with the second aspect, the present invention provides a first implementation manner of the second aspect, wherein the concentration of trivalent iron ions in the etching aqueous solution and the iron ion concentration in the ethylene glycol aqueous solution is 0.01-1 mol / L.

[0010] In combination with the second aspect, the present invention provides a second implementation of the second aspect, wherein the concentration of trivalent iron ions in the etching aqueous solution and the iron ion concentration in the ethylene glycol aqueous solution is 0.1 mol / L.

[0011] In combination with the second aspect, the present invention provides a third embodiment of the second aspect, wherein the source of trivalent iron ions comprises: one or more of ferric acetate, ferric nitrate, ferric sulfate, ferric chloride, and ferric phosphate, preferably ferric chloride; The nickel-molybdenum alloy used as the substrate is one or more of nickel-molybdenum alloy powder, nickel-molybdenum alloy sheet, nickel-molybdenum alloy plate, nickel-molybdenum alloy foil, and foamed nickel-molybdenum alloy, preferably foamed nickel-molybdenum alloy.

[0012] In combination with the second aspect, the present invention provides a fourth implementation of the second aspect, wherein the nickel-molybdenum alloy is immersed in the ethylene glycol aqueous solution containing trivalent iron ions for 1-48 hours.

[0013] In combination with the second aspect or the second embodiment of the second aspect, the present invention provides a fifth embodiment of the second aspect, wherein the nickel-molybdenum alloy is immersed in the ethylene glycol aqueous solution containing trivalent iron ions for 12 hours.

[0014] In combination with the second aspect, the present invention provides a sixth implementation of the second aspect: the specific steps are as follows: First, a nickel-molybdenum alloy with a nickel-to-molybdenum ratio of 1:1 was immersed in a hydrochloric acid solution for ultrasonic cleaning, and then ultrasonically cleaned in acetone; Then, the cleaned nickel-molybdenum alloy is dried and immersed in a prepared aqueous solution containing trivalent iron ions and ethylene glycol, taken out and washed with deionized water, and then dried in a natural environment.

[0015] In a fourth aspect, the present invention also provides an application, in which the nickel-iron metal hydroxide / nickel-molybdenum alloy material prepared by the preparation method of the second aspect is used to form two materials with different surface contact ratios of nickel-iron metal hydroxide and nickel-molybdenum alloy by adjusting the iron ion ratio of the etching aqueous solution and the immersion time during the preparation process, and the two materials are used as positive and negative electrode materials in electrolyzed water, respectively.

[0016] The beneficial effects of the present invention are: 1. The present invention utilizes nickel-molybdenum foam as both the raw material for the current collector and the catalytic active sites. A one-step process of trivalent iron ion etching is used to form fresh crystal nuclei on the surface of the nickel-molybdenum foam. The foam is then exposed to air, where the nickel from the nickel-molybdenum foam and the adsorbed iron spontaneously grow on the surface of the nickel-molybdenum alloy to form layered double hydroxide nanosheets. 2. The electrode material of the present invention has a rich nanosheet structure on its surface, which has a high specific surface area and can be firmly bonded to the conductive substrate. This structure has both good conductivity and structural stability. Even at industrial high current density, it can still maintain good catalytic activity and long-term stability. 3. The preparation process of the present invention is simple, the reaction conditions are mild, the raw materials are cheap, there is no pollutant emission, and it is easy to produce on a large scale; 4. In the application mode adopted by the present invention, the immersion time and the concentration of iron ions are adjusted to change the surface area of nickel-iron hydroxide covering the surface of the material, thereby adaptively adjusting the electrodes used for the cathode / anode to improve the corresponding electrolytic gas production efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 1 is a scanning electron microscope image of the surface of the nickel-iron metal hydroxide / nickel-molybdenum alloy electrode prepared in an embodiment of the present invention; Figure 2 1 is a linear sweep voltammetry curve of oxygen evolution reaction of several materials prepared in the embodiment of the present invention; Figure 3 1 is a linear sweep voltammetry curve of hydrogen evolution reaction of several materials prepared in the embodiment of the present invention; Figure 4 1 is a graph showing the durability test of the oxygen evolution reaction of the nickel-iron metal hydroxide / nickel-molybdenum alloy material prepared in an embodiment of the present invention; Figure 5 This is a hydrogen evolution reaction durability test curve of the nickel-iron metal hydroxide / nickel-molybdenum alloy material prepared in the embodiment of the present invention. DETAILED DESCRIPTION

[0018] The present invention will be further explained below with reference to the accompanying drawings and specific embodiments.

[0019] In order to make the purpose, technical solutions and advantages of the embodiments of the present application clearer, the technical solutions in the embodiments of the present application will be clearly and completely described below in combination with the drawings in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, not all of the embodiments.

[0020] Therefore, the following detailed description of the embodiments of the present application provided in the accompanying drawings is not intended to limit the scope of the present application for protection, but merely represents selected embodiments of the present application. All other embodiments obtained by persons of ordinary skill in the art based on the embodiments in the present application without making any creative efforts shall fall within the scope of protection of the present application.

[0021] Example 1: This embodiment discloses a self-supporting electrolytic water catalytic electrode material, which is used as an electrode material for electrolysis of water. Specifically, it includes a foamed nickel-molybdenum alloy as a substrate, and the surface of the foamed nickel-molybdenum alloy is covered with a two-dimensional layered nickel-iron metal hydroxide.

[0022] As a possible implementation, the nickel-molybdenum alloy includes any one or more of nickel-molybdenum alloy powder, nickel-molybdenum alloy sheet, nickel-molybdenum alloy plate, nickel-molybdenum alloy foil, and nickel-molybdenum alloy foam. In this embodiment, nickel-molybdenum alloy foam is used as the substrate. By utilizing its maximum specific surface area, it can better adapt to the subsequent immersion step to achieve a better natural growth effect. However, other materials used can also achieve similar effects based on this application and can be considered as equivalent replacements within the scope of protection of this application.

[0023] For this electrode material, this embodiment also provides a preparation method, which is to pretreat and clean the foamed nickel-molybdenum alloy material, immerse the treated foamed nickel-molybdenum alloy material in an etching aqueous solution containing a solute including trivalent iron ions and ethylene glycol, and etch it. After etching, the material is cleaned and dried in a natural environment to form a nickel-iron metal hydroxide / nickel-molybdenum alloy material.

[0024] Regarding the manufacturing method using nickel-iron metal hydroxide / nickel-molybdenum alloy material in the above embodiment, the preferred conditions include: (1) The concentration of trivalent iron ions in the etching solution and the iron ion concentration in the ethylene glycol aqueous solution is 0.01-1 mol / L; (2) The source of trivalent iron ions includes one or more of ferric acetate, ferric nitrate, ferric sulfate, ferric chloride, and ferric phosphate, preferably ferric chloride; (3) The nickel-molybdenum alloy is immersed in the ethylene glycol aqueous solution containing trivalent iron ions for 1 to 48 hours.

[0025] In view of the above conditions, several implementation plans are provided for illustration.

[0026] Implementation Plan 1 A nickel-iron layered double hydroxide-nickel-molybdenum foam composite material, the preparation method of which is as follows: The nickel-molybdenum foam with a nickel-to-molybdenum mass ratio of 1:1 was immersed in a 3 mol / L hydrochloric acid aqueous solution for ultrasonic cleaning for 15 minutes, and then ultrasonically cleaned in an acetone solution for 15 minutes to obtain a treated nickel-molybdenum foam alloy.

[0027] Prepare an ethylene glycol aqueous solution with a volume fraction of 1:9, add ferric chloride reagent thereto, and disperse evenly. The concentration of the ferric chloride in the ethylene glycol aqueous solution is 0.1 mol / L.

[0028] The nickel-molybdenum alloy foam obtained in the previous step was immersed in a prepared ferric chloride-ethylene glycol aqueous solution and reacted for 12 hours. After the reaction, it was rinsed with deionized water and air-dried to obtain a self-supporting catalytic electrode with nickel-iron layered double hydroxide supported on the nickel-molybdenum alloy, denoted as nickel-iron hydroxide / nickel-molybdenum (NiFe-LDH / NiMo) catalytic electrode.

[0029] Scanning electron microscope images of the catalytic electrode surface prepared in this scheme, such as Figure 1 As shown, the surface of the catalytic electrode is a uniformly distributed iron-nickel layered hydroxide nanosheet structure.

[0030] Implementation Plan 2 The nickel-molybdenum foam with a mass ratio of 1:1 according to the first embodiment was ultrasonically cleaned in a hydrochloric acid solution and acetone for 15 minutes respectively, and then naturally dried. The obtained sample was recorded as nickel-molybdenum.

[0031] Implementation Plan 3 Materials and parameters Nickel-molybdenum alloy foam (Ni:Mo = 1:1, porosity 85%) was cut into 1 cm × 4 cm strips, weighing approximately 0.5 g. The etching solution was a 0.01 mol / L ferric chloride (FeCl3・6H2O) aqueous solution in ethylene glycol, with a volume ratio of ethylene glycol to water of 1:9 (mix 5 mL of ethylene glycol with 45 mL of deionized water, and add 0.135 g of FeCl3・6H2O to dissolve it), for a total volume of 50 mL. Cleaning reagents included deionized water (resistivity ≥ 18.2 MΩ・cm) and analytical grade acetone.

[0032] First, pre-treat the nickel-molybdenum alloy foam by immersing it in 3 mol / L hydrochloric acid solution and acetone in turn, and ultrasonically cleaning it for 15 minutes each time (ultrasonic power 100 W, frequency 40 kHz) to remove the surface oxide layer and oil stains. Rinse it with deionized water three times for 1 minute each time, and dry it in a 60°C oven for 2 hours. The dried alloy was vertically immersed in the etching solution and allowed to stand at room temperature of 25°C for 1 hour, during which time it was gently stirred at a speed of 50 rpm to promote mass transfer.

[0033] The alloy was taken out, rinsed with deionized water until neutral (detected by pH paper), and dried naturally in air (ambient humidity ≤ 50%, temperature 25°C) to obtain a sample.

[0034] The focus of this solution is to explore the effect of the lower limit of iron ion concentration on etching efficiency and nanosheet growth, which is suitable for scenarios where the mechanical strength of the substrate needs to be retained. 3+ (0.01mol / L) only induces a mild redox reaction on the alloy surface (Ni+2Fe 3+ →Ni 2+ +2Fe 2+ ), the etching depth is about 50nm, and the released Ni 2+ With adsorbed Fe 3+ Sparse nickel-iron layered hydroxide (NiFe-LDH) nanosheets with a thickness of about 10-20 nm are formed under air oxidation, avoiding excessive etching that leads to loose substrate structure.

[0035] Implementation Plan 4 The size and pretreatment steps of the nickel-molybdenum foam alloy were the same as those in Implementation Plan 3. The etching solution was a 0.1 mol / L ferric chloride aqueous solution in ethylene glycol, with a volume ratio of ethylene glycol to water of 1:1 (25 mL ethylene glycol + 25 mL deionized water, 1.35 g FeCl3·6H2O was added to dissolve), and the total solution volume was 50 mL. The etching time was 48 hours.

[0036] The pretreatment is the same as in the third embodiment; then the etching reaction is carried out, the alloy is immersed in the etching solution, and it is left at room temperature for 48 hours, and the etching solution is replaced once a day during this period to avoid Fe 2+ The sample was then washed with deionized water 5 times for 2 minutes each time and dried in an oven at 60°C for 3 hours to obtain the sample. This implementation plan focuses on studying the effects of high iron ion concentrations on nanosheet thickness and catalytic activity, and is suitable for scenarios requiring a high active site density.

[0037] Implementation Plan 5 The size and pretreatment steps of the nickel-molybdenum foam alloy are the same as those in Implementation Plan 3. The etching solution is a 0.5 mol / L ferric chloride aqueous solution in ethylene glycol, with a volume ratio of ethylene glycol to water of 1:1 (25 mL ethylene glycol + 25 mL deionized water, 6.75 g FeCl3·6H2O added to dissolve), and the total solution volume is 50 mL. The etching time is then 8 hours.

[0038] The pretreatment is the same as in the third embodiment; then the etching reaction is carried out, the alloy is immersed in the etching solution, and it is left at room temperature for 48 hours, and the etching solution is replaced once a day during this period to avoid Fe 2+ The sample was then washed with deionized water for 5 times, 2 minutes each time, and dried naturally at room temperature for 12 hours to obtain the sample. The focus of this implementation plan is to change the concentration of the iron ion solution and coordinate it with the etching time to check its etching effect.

[0039] Then, two comparison groups were prepared for comparison test with the sample materials of the first embodiment, wherein: Comparative Example 1: 5 mg of commercial ruthenium dioxide catalyst, 900 μL of isopropanol, 50 μL of deionized water, and 50 μL of a 0.5% mass fraction Nafion solution were mixed and ultrasonically dispersed for 30 minutes. The resulting mixture was then added dropwise to the surface of a glassy carbon electrode and allowed to dry naturally to obtain a ruthenium dioxide electrode material.

[0040] Comparative Example 2: 5 mg of commercial platinum-carbon catalyst, 900 μL of isopropanol, 50 μL of deionized water, and 50 μL of 0.5% Nafion solution were mixed and ultrasonically dispersed for 30 minutes. The resulting mixture was then added dropwise to the surface of a glassy carbon electrode and allowed to dry naturally to obtain a platinum-carbon catalytic electrode material.

[0041] Performance testing: The nickel-iron hydroxide / nickel-molybdenum electrode prepared in Implementation Example 1, the nickel-molybdenum electrode prepared in Implementation Example 2, and the ruthenium dioxide electrode prepared in Comparative Example 1 were respectively used as working electrodes, a graphite rod was used as a counter electrode, a mercury / mercuric oxide electrode was used as a reference electrode, and the electrolyte was a 1 mol / L potassium hydroxide aqueous solution. A three-electrode system was assembled, and the hydrogen evolution reaction and the oxygen evolution reaction of the catalytic electrode were evaluated by linear sweep voltammetry curves. The scan rate of the linear sweep voltammetry test was 5 mV / s. The linear sweep voltammetry curves of the oxygen evolution reaction and the hydrogen evolution reaction obtained by the test were shown as follows: Figure 2 and Figure 3 shown.

[0042] Depend on Figure 2 It can be seen that at 100mA / cm 2 At a current density of 1.5 Å, the overpotentials of NiFe-LDH / NiMo, RuO2 and NiMo electrodes are 290 mV, 410 mV and 450 mV, respectively, indicating that the catalytic performance of NiFe-LDH / NiMo in oxygen evolution reaction is significantly better than that of commercial RuO2 and foamed NiMo alloy.

[0043] Depend on Figure 3 It can be seen that at 100mA / cm 2 At a current density of 1.5 Å, the overpotentials of NiFe-LDH / NiMo, commercial Pt / C and NiMo electrodes are 289 mV and 339 mV, respectively, indicating that the catalytic performance of NiFe-LDH / NiMo for hydrogen evolution reaction is significantly better than that of commercial Pt / C and foamed NiMo alloy.

[0044] The nickel iron hydroxide / nickel molybdenum electrode prepared in Implementation Plan 1 was used as the working electrode, the graphite rod was used as the counter electrode, and the mercury / mercury oxide electrode was used as the reference electrode. The stability of the oxygen evolution reaction and hydrogen evolution reaction of the nickel iron hydroxide / nickel molybdenum electrode was tested in a three-electrode system.

[0045] Figure 4 and Figure 5 The nickel iron hydroxide / nickel molybdenum electrodes prepared were respectively subjected to a current density of 500 mA / cm 2 The time-current curves of oxygen evolution reaction and hydrogen evolution reaction are shown in Figure 1. Figure 4 and Figure 5 It can be seen that after a long period of testing, the current density of nickel iron hydroxide / nickel molybdenum has no obvious attenuation, indicating that the nickel iron hydroxide / nickel molybdenum electrode has long-term stability in hydrogen evolution reaction and oxygen evolution reaction, and has the potential for application in industrial high current scenarios.

[0046] As an implementation method, in order to improve the efficiency of its natural growth, the alloy electrode material after etching in this embodiment is placed in a closed container with acidic gas vapor and left to dry for 3 hours, or placed in a closed container with high concentration of oxygen and steam and left to stand for about 5 hours. This optimization method can improve its natural growth efficiency. Compared with the method of air drying at room temperature, the thickness of the outer nickel-iron layer material is larger in the same time.

[0047] The present invention is not limited to the above optional embodiments. Anyone can derive various other forms of products based on the teachings of the present invention. The above specific embodiments should not be construed as limiting the scope of protection of the present invention. The scope of protection of the present invention shall be based on the scope defined in the claims, and the description can be used to interpret the claims.

Claims

1. A self-supporting catalytic electrode material for water electrolysis, characterized in that: The invention comprises a nickel-molybdenum alloy as a substrate, wherein the surface of the nickel-molybdenum alloy is covered with a two-dimensional layered nickel-iron metal hydroxide.

2. A preparation method, characterized in that: For making a self-supporting electrolytic water catalytic electrode material as described in claim 1, the foamed nickel-molybdenum alloy material is first pretreated and cleaned, and the treated nickel-molybdenum alloy material is immersed in an etching aqueous solution containing a solute including trivalent iron ions and ethylene glycol for etching. After etching, the material is cleaned and dried in a natural environment to form a nickel-iron metal hydroxide / nickel-molybdenum alloy material.

3. A preparation method according to claim 2, characterized in that: The concentration of the trivalent iron ions in the etching aqueous solution and the iron ions in the ethylene glycol aqueous solution is 0.01-1 mol / L.

4. A preparation method according to claim 2, characterized in that: The concentration of the trivalent iron ions in the etching aqueous solution and the iron ions in the ethylene glycol aqueous solution is 0.1 mol / L.

5. A preparation method according to claim 2, characterized in that: The source of trivalent iron ions includes: one or more of ferric acetate, ferric nitrate, ferric sulfate, ferric chloride, and ferric phosphate, preferably ferric chloride; The nickel-molybdenum alloy used as the substrate is one or more of nickel-molybdenum alloy powder, nickel-molybdenum alloy sheet, nickel-molybdenum alloy plate, nickel-molybdenum alloy foil, and foamed nickel-molybdenum alloy, preferably foamed nickel-molybdenum alloy.

6. A preparation method according to claim 2, characterized in that: The nickel-molybdenum alloy is immersed in the ethylene glycol aqueous solution containing trivalent iron ions for 1-48 hours.

7. A preparation method according to claim 2 or 4, characterized in that: The nickel-molybdenum alloy is immersed in the ethylene glycol aqueous solution containing trivalent iron ions for 12 hours.

8. A preparation method according to claim 2, characterized in that: The specific steps are as follows: First, a nickel-molybdenum alloy with a nickel-to-molybdenum ratio of 1:1 was immersed in a hydrochloric acid solution for ultrasonic cleaning, and then ultrasonically cleaned in acetone; Then, the cleaned nickel-molybdenum alloy is dried and immersed in a prepared aqueous solution containing trivalent iron ions and ethylene glycol, taken out and washed with deionized water, and then dried in a natural environment.

9. An application, characterized in that: The nickel-iron metal hydroxide / nickel-molybdenum alloy material prepared by the preparation method of claim 2 is formed by adjusting the iron ion ratio of the etching aqueous solution and the immersion time during the preparation process to form two materials with different surface contact ratios of nickel-iron metal hydroxide and nickel-molybdenum alloy, which are used as positive and negative electrode materials in electrolyzed water, respectively.

Images