Preparation method and application of medium-high entropy self-supporting oxygen reaction catalyst synthesized by photo-assisted electro-deposition method at room temperature

Abstract

The invention belongs to the technical field of new energy materials, and discloses a preparation method and application of a medium-high entropy self-supporting oxygen reaction catalyst synthesized by a photo-assisted electrodeposition method at room temperature. The method comprises the following steps: cutting and cleaning foamed nickel, taking the foamed nickel as a working electrode, carrying out electro-deposition in an electrolyte containing a specific metal salt and a reducing agent by utilizing a three-electrode system under the conditions of illumination and constant voltage, and washing and drying to obtain the catalyst. The problems that in the prior art, an oxygen evolution reaction catalyst is low in efficiency and poor in corrosion resistance in the seawater electrolysis process are solved, the medium-high-entropy self-supporting oxygen reaction catalyst with excellent catalytic activity and corrosion resistance is provided, the medium-high-entropy self-supporting oxygen reaction catalyst is suitable for the field of seawater electrolysis hydrogen production, and meanwhile the effects of improving the electrolysis efficiency and reducing energy consumption are achieved.

Description

Technical Field

[0001] The present invention belongs to the technical field of new energy materials, and specifically relates to a preparation method and application of a medium-high entropy self-supporting oxygen reaction catalyst synthesized by light-assisted electrodeposition at room temperature. Background Art

[0002] With the growth of global energy demand and the urgency of addressing climate change, the pace of development of sustainable and clean energy technologies has accelerated, especially in replacing fossil fuels. Hydrogen energy, with its high energy density and environmental friendliness, is regarded as an ideal alternative energy source. Water electrolysis hydrogen production technology has become an important way to decarbonize the global industry due to its cleanliness and feasibility, especially in the fields of energy, transportation, manufacturing and agriculture. In order to promote the development of hydrogen energy infrastructure, it is particularly important to improve the efficiency of water electrolysis. Among them, the development of efficient and economical oxygen evolution reaction (OER) catalysts has become a key issue to be solved urgently, because OER is the main link of energy loss in the water electrolysis process. In the process of water electrolysis, the kinetic efficiency of oxygen evolution reaction is low and it is highly dependent on rare key raw materials, which is particularly prominent in the application of iridium (Ir) and ruthenium (Ru); although iridium and ruthenium are the preferred anode catalysts due to their excellent stability, they are also relatively rare precious metals on the earth. Therefore, it is necessary to develop low-cost, efficient and stable non-precious metal catalysts to replace commercial precious metal catalysts (such as RuO 2 and IrO 2 ), which is of great significance for promoting the widespread application of hydrogen energy technology. At the same time, with the increasing shortage of freshwater resources worldwide, seawater electrolysis has gradually become a technology direction that has attracted much attention due to its wide availability and sustainability. However, the complex ions and impurities in seawater have put forward higher requirements on the selectivity and corrosion resistance of catalysts. Therefore, the development of corrosion-resistant, highly active and highly selective catalysts for seawater electrolysis has become a key challenge in current research.

[0003] Medium and high entropy compounds are considered as potential catalysts for OER due to their excellent corrosion resistance, high stability, enhanced catalytic activity, improved electrolysis efficiency and long-term stable operation. In particular, first transition metals have shown significant catalytic activity in the OER process in an alkaline environment. Among them, cobalt, nickel, iron, manganese, zinc, titanium and vanadium-based materials have become the focus of research due to their high crustal abundance and excellent catalytic performance.

[0004] However, it is urgent to further improve the catalytic activity and stability of high entropy compounds in transition metals in the electrolysis of seawater. Theoretical analysis shows that in the electrolysis of seawater, the OER process is affected by the high concentration of chloride ions on the anode, which competes with the OER and reduces the efficiency of the catalyst.- It is highly corrosive and will corrode the electrode, thereby reducing the durability and stability of the electrode; while calcium and magnesium ions and other insoluble substances in seawater may adhere to the electrode surface during the electrolysis process, blocking the catalytic active sites and causing the catalyst to deactivate rapidly. Experimental studies have shown that medium- and high-entropy compounds exhibit significant catalytic activity and long-term stability in the field of seawater electrolysis. This is mainly attributed to the construction of corrosion-resistant medium- and high-entropy compounds on the surface of self-supporting electrodes, thereby improving their OER catalytic performance. However, in practical applications, transition metal compound materials still face many challenges: calcium ions (Ca 2+ ), magnesium ion (Mg 2+ ) and chloride ions (Cl - ) will bring about a series of complex problems. How to use the high entropy effect to enhance the stability of OER under seawater conditions and further improve the catalytic activity of seawater electrolysis is still a key topic in current research. Summary of the invention

[0005] In order to solve the problem in the prior art that high concentration of chloride ions undergo chlorine oxidation reaction on the anode resulting in poor catalytic activity and stability, the present invention provides a preparation method and application of a medium-high entropy self-supporting oxygen reaction catalyst synthesized by light-assisted electrodeposition at room temperature, which exhibits excellent corrosion resistance in the electrolysis of seawater. The method of the present invention is simple and easy to control, and can achieve rapid preparation of materials, thereby solving the problems of high energy consumption and difficult synthesis in the preparation technology of medium-high entropy compound catalysts.

[0006] To achieve the above object, the present invention provides the following technical solutions:

[0007] A method for preparing a medium-high entropy self-supporting oxygen reaction catalyst synthesized by light-assisted electrodeposition at room temperature comprises the following steps:

[0008] a. First, cut the nickel foam, put it into acetone solution to remove the oil stains on the surface by ultrasonic, rinse it with deionized water several times to remove the acetone on the surface, and then use dilute hydrochloric acid to ultrasonically remove the surface oxide layer, take out the nickel foam and rinse it to neutral, and vacuum dry it at 60℃ for 12h for later use;

[0009] b. Ultrasonicate different metal salts and reducing agents in deionized water until they are dissolved, and pour the prepared solutions into the electrolytic cell;

[0010] c. In a three-electrode system, nickel foam is used as the working electrode, silver chloride electrode is used as the reference electrode, and platinum electrode is used as the counter electrode. The electrolyte is the solution prepared in step b. During the experiment, electrodeposition is performed under a certain light intensity and a constant voltage. After washing and drying the deposited nickel foam, a medium-high entropy self-supporting oxygen reaction catalyst can be obtained.

[0011] Further, the metal salt includes several of iron sulfate, manganese sulfate, nitrate, sulfate or acetate of cobalt, nickel, zinc, vanadium and copper, and the reducing agent includes one of hydrazine hydrate, sodium borohydride, sodium sulfite, sodium thiosulfate, sodium borate and potassium tetraborate.

[0012] Furthermore, the amount of the metal salt substance is 20-52 mmol, the amount of the reducing agent substance is 0.3-2 mol, and the amount of deionized water is 50-100 mL.

[0013] Furthermore, the metal salt is 8 mmol of cobalt nitrate hexahydrate, 8 mmol of nickel sulfate hexahydrate, 8 mmol of manganese sulfate monohydrate, 20 mmol of ferrous sulfate heptahydrate, and 8 mmol of zinc acetate dihydrate; the reducing agent is 0.3 mol of potassium tetraborate; and the deionized water is 100 mL.

[0014] Furthermore, the light intensity is light intensity AM 1.5G.

[0015] Furthermore, the three-electrode system is an experimental device in electrochemical research, which consists of three main parts: working electrode (WE), counter electrode (CE) and reference electrode (RE), and the constant voltage is set to -0.3~1V, and the electrodeposition process is maintained for 0.5~120 minutes.

[0016] Furthermore, the washing and drying operation in step c is to rinse the deposited nickel foam several times and put it into a vacuum drying oven, and then dry it at 60° C. for 12 hours.

[0017] A medium-to-high entropy self-supporting oxygen reaction catalyst synthesized by light-assisted electrodeposition at room temperature, and its application in seawater electrolysis and offshore engineering.

[0018] An application of a medium-high entropy self-supporting oxygen reaction catalyst synthesized by light-assisted electrodeposition at room temperature, comprising:

[0019] (1) Electrocatalytic oxygen evolution reaction: The prepared medium-high entropy self-supporting catalyst was used as the working electrode, the platinum sheet as the counter electrode, and silver chloride as the reference electrode to carry out OER test in 1 M KOH electrolyte solution.

[0020] (2) Electrochemical performance test: The OER performance was evaluated by linear sweep voltammetry and AEM electrolyzer device test. In addition, the stability and durability of the catalyst were evaluated by Tafel plot and chronopotentiometry, and its catalytic active sites were studied by XPS and Raman.

[0021] Beneficial Effects

[0022] The present invention designs a light-assisted electrodeposition technology for synthesizing medium-high entropy compound self-supporting oxygen reaction catalysts, achieving the corrosion resistance and long-term stability of transition metal compounds in the field of hydrogen production by electrolysis of seawater. The technology significantly enhances the inherent activity of oxygen evolution reaction by designing a medium-high entropy transition metal compound system with controllable elements. The medium-high entropy metal compound self-supporting electrode shows excellent performance in the field of water electrolysis catalysis, and its performance in achieving low overpotential is particularly outstanding. Compared with ternary compounds, its overpotential is reduced by more than 50-100mV, which is significantly better than most existing metal compound-based oxygen evolution reaction catalysts in performance; this progress not only reflects the significant improvement of the electrocatalytic activity of medium-high entropy metal compounds, but also highlights its potential in improving the efficiency of seawater electrolysis, providing a new direction for the development of new high-efficiency non-precious metal electrocatalysts. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 is a scanning electron microscope photograph of the medium-high entropy self-supporting oxygen reaction catalyst sample prepared in Example 1;

[0024] Figure 2 is a transmission electron microscope photograph of the medium-high entropy self-supporting oxygen reaction catalyst sample prepared in Example 2 after testing;

[0025] Figure 3 It is a linear sweep voltammetric curve of the catalytic performance of the medium-high entropy self-supporting oxygen reaction catalyst sample prepared in Example 2 and the blank nickel foam sample in Comparative Example 1;

[0026] Figure 4 It is a Tafel slope diagram of the catalytic performance of the medium-high entropy self-supporting oxygen reaction catalyst sample prepared in Example 2 and the blank nickel foam sample in Comparative Example 1;

[0027] Figure 5 It is a linear sweep voltammetry curve of the high entropy self-supporting oxygen reaction catalyst prepared in Example 2 and Comparative Example 2 with or without additional light source;

[0028] Figure 6 It is a linear sweep voltammetric curve of the catalytic performance of the medium-high entropy self-supporting oxygen reaction catalyst prepared in Example 2 under simulated seawater and real seawater conditions;

[0029] Figure 7 is a Tafel slope diagram of the catalytic performance of the medium-high entropy self-supporting oxygen reaction catalyst prepared in Example 2 under simulated seawater and real seawater conditions;

[0030] Figure 8 The corrosion resistance of the medium-high entropy self-supporting oxygen reaction catalyst prepared in Example 2 under different electrolyte conditions;

[0031] Fig. 9This is the corrosion resistance of the medium-high entropy self-supporting oxygen reaction catalyst prepared in Example 3 under different electrolyte conditions;

[0032] Fig.10 is a linear sweep voltammetric curve of the medium-high entropy self-supporting oxygen reaction catalyst prepared in Example 2 in an electrolytic cell;

[0033] Fig.11 is a chronopotentiometry test curve of the medium-high entropy self-supporting oxygen reaction catalyst prepared in Example 2 in an alkaline electrolyzer;

[0034] Fig.12 The XPS fine spectrum of O of the medium-high entropy self-supporting oxygen reaction catalyst prepared in Example 2 before and after the chronopotentiometry test;

[0035] Fig.13 is a Raman spectrum of the medium-high entropy self-supporting oxygen reaction catalyst prepared in Example 2 before and after the chronopotentiometry test;

[0036] Fig.14 This is a physical comparison of the high-entropy self-supporting oxygen reaction catalyst and nickel foam synthesized by light-assisted electrodeposition at room temperature. DETAILED DESCRIPTION

[0037] The technical solution of the present invention is further described below in conjunction with specific embodiments.

[0038] The present invention provides a method for preparing a medium-high entropy self-supporting oxygen reaction catalyst synthesized by light-assisted electrodeposition at room temperature, wherein medium-high entropy boride is deposited on the surface of nickel foam by light-assisted electrodeposition, and the medium-high entropy compound is converted into MOOH (M=metal ion) with high oxidation activity during the test process, so that the original film structure of particle accumulation is converted into a nanosheet structure. The electrochemically active surface area of ​​the catalyst is increased, and the surface of the catalyst of the present invention is reconstructed, and the constructed nanosheet not only accelerates the charge transfer, but also exposes more active sites, which provides a strong guarantee for the synergistic effect of different metal active site species to improve the OER activity and the seawater corrosion resistance.

[0039] When the high entropy catalyst was tested in the oxidation process at room temperature, only 248 mV overpotential was required in alkaline electrolyte to obtain 10 mA cm -2 Considering that medium-high entropy catalysts have excellent electrocatalytic activity for the OER process, an alkaline electrolyzer is constructed using medium-high entropy catalysts as oxidation electrodes and nickel mesh as the reduction electrode. The current density can reach 1A at 2V and 50mA cm -2 It can run stably for more than 150 hours and has excellent electrochemical activity and stability.

[0040] The preparation method of the above-mentioned medium-high entropy compound catalyst (Example 1) comprises the following specific steps:

[0041] (1) Cleaning nickel foam: First, cut the nickel foam produced by the factory, then put it into a deacetone solution and ultrasonically remove the oil stains on the surface. Then, rinse the degreased nickel foam with deionized water several times to remove the acetone on the surface. Then, put it into a dilute hydrochloric acid solution and ultrasonically remove the surface oxide layer. Finally, rinse the nickel foam until it is neutral and put it into a vacuum drying oven and dry it at 60°C for 12 hours.

[0042] (2) Preparation of electrolyte: a certain proportion of cobalt nitrate hexahydrate, nickel sulfate hexahydrate, manganese sulfate monohydrate, ferrous sulfate heptahydrate, zinc acetate dihydrate, etc. and potassium tetraborate are ultrasonically dissolved in deionized water.

[0043] (3) Preparation of medium-high entropy compounds: A dried nickel foam is fixed on an electrode holder as a working electrode, a silver chloride electrode is used as a reference electrode, and a platinum electrode is used as a counter electrode. During the experiment, a xenon lamp is used as a light source to simulate a lighting environment close to natural sunlight under laboratory conditions, and electrochemical deposition is performed under constant potential. After washing and drying, a medium-high entropy catalyst can be obtained.

[0044] Xenon lamp light source intensity AM 1.5G is used to simulate the standard spectrum of the earth's surface light source system, which is used for solar energy conversion efficiency testing and photochemical experiments. Xenon lamp light source is a light source that emits light by discharging high-pressure or ultra-high-pressure xenon gas. The light it emits is a continuous spectrum with energy distribution from 200 to 2000nm, and the energy distribution characteristics of xenon lamps are very similar to those of the solar spectrum.

[0045] Example 1

[0046] a. Add 5 mmol of cobalt nitrate hexahydrate (Co(NO 3 ) 2 6H 2 O), 5 mmol of nickel sulfate hexahydrate (NiSO 4 6H 2 O), 5mmol manganese sulfate monohydrate (MnSO 4 ·H 2 O), 5mmol ferrous sulfate heptahydrate (FeSO 4 7H 2 O), and 0.5 mol sodium borohydride (NaBH 4 ) was dissolved in 50 mL of deionized water and ultrasonicated for 30 minutes to promote dissolution. Subsequently, the resulting solution was transferred to an electrolytic cell for subsequent use.

[0047] b. In the three-electrode system, 1×1 cm2 nickel foam was used as the working electrode and fixed, a silver chloride electrode was used as the reference electrode, a platinum electrode was used as the counter electrode, and the electrolyte was the above-prepared solution. During the experiment, the light intensity was set to AM 1.5G, the constant voltage was maintained at -1V, the electrodeposition process was maintained for 30 minutes, and after light-assisted electrodeposition, deionized water was used to thoroughly wash to remove surface impurities, and finally vacuum dried to obtain a medium-high entropy metal compound nanostructure self-supporting material.

[0048] c. Use field emission scanning electron microscopy (SEM) to characterize the sample microstructure in detail.

[0049] Example 2

[0050] a. Add 8 mmol of cobalt nitrate hexahydrate (Co(NO 3 ) 2 6H 2 O), 8 mmol of nickel sulfate hexahydrate (NiSO 4 6H 2 O), 8 mmol manganese sulfate monohydrate (MnSO 4 ·H 2 O), 20mmol ferrous sulfate heptahydrate (FeSO 4 7H 2 O), 8mmol zinc acetate dihydrate (Zn(CH 3 COO 2 ·2H 2 O) and 0.3 mol potassium tetraborate (K 2 B 4 O 7 ·4H 2 (0) was dissolved in 100 mL of deionized water and ultrasonicated for 30 minutes to promote dissolution. Subsequently, the resulting solution was transferred to an electrolytic cell for subsequent use.

[0051] b. In the three-electrode system, 1×1 cm2 nickel foam was used as the working electrode and fixed, a silver chloride electrode was used as the reference electrode, a platinum electrode was used as the counter electrode, and the electrolyte was the above-prepared solution. During the experiment, the light intensity was set to AM 1.5G, the constant voltage was maintained at -0.5V, the electrodeposition process was maintained for 30 minutes, and after the light-assisted electrodeposition, deionized water was used to thoroughly wash to remove surface impurities, and finally vacuum dried to obtain a medium-high entropy metal compound nanostructure self-supporting material.

[0052] c. Field emission transmission electron microscopy (TEM) is used to characterize the sample's microscopic morphology in detail.

[0053] d. Characterization of the OER performance of the material at a scan rate of 10 mV s -1The linear sweep voltammetry (LSV) polarization curve was tested in the voltage range of 0V to 1V (vs. RHE) and its Tafel slope was fitted.

[0054] Example 3

[0055] a. Add 7 mmol of nickel sulfate hexahydrate (NiSO 4 6H 2 O), 7 mmol manganese sulfate monohydrate (MnSO 4 ·H 2 O), 7mmol ferrous sulfate heptahydrate (FeSO 4 7H 2 O), 7mmol zinc acetate dihydrate (Zn(CH 3 COO 2 ·2H 2 O) and 2 mol sodium sulfite (Na 2 SO 3 ) was dissolved in 50 mL of deionized water and ultrasonicated for 30 minutes to promote dissolution. Subsequently, the resulting solution was transferred to an electrolytic cell for subsequent use.

[0056] b. In the three-electrode system, 1×1 cm2 nickel foam was used as the working electrode and fixed, a silver chloride electrode was used as the reference electrode, a platinum electrode was used as the counter electrode, and the electrolyte was the above-prepared solution. During the experiment, the light intensity was set to AM 1.5G, the constant voltage was maintained at -0.4V, the electrodeposition process was maintained for 3 minutes, and after light-assisted electrodeposition, deionized water was used to thoroughly wash to remove surface impurities, and finally vacuum dried to obtain a medium-high entropy metal compound nanostructure self-supporting material.

[0057] Example 4

[0058] a. Add 10 mmol of cobalt nitrate hexahydrate (Co(NO 3 ) 2 6H 2 O), 8 mmol manganese sulfate monohydrate (MnSO 4 ·H 2 O), 8mmol ferrous sulfate heptahydrate (FeSO 4 7H 2 O), 15mmol zinc acetate dihydrate (Zn(CH 3 COO 2 ·2H 2 O) and 1 mol hydrazine hydrate (N 2 H 4 ·H 2 (0) was dissolved in 100 mL of deionized water and ultrasonicated for 30 minutes to promote dissolution. Subsequently, the resulting solution was transferred to an electrolytic cell for subsequent use.

[0059] b. In the three-electrode system, 1×1 cm2 nickel foam was used as the working electrode and fixed, a silver chloride electrode was used as the reference electrode, a platinum electrode was used as the counter electrode, and the electrolyte was the above-prepared solution. During the experiment, the light intensity was set to AM 1.5G, the constant voltage was maintained at -0.7V, the electrodeposition process was maintained for 1 minute, and after light-assisted electrodeposition, deionized water was used to thoroughly wash to remove surface impurities, and finally vacuum dried to obtain a medium-high entropy metal compound nanostructure self-supporting material.

[0060] Example 5

[0061] a. Add 4 mmol of cobalt nitrate hexahydrate (Co(NO 3 ) 2 6H 2 O), 8 mmol of nickel sulfate hexahydrate (NiSO 4 6H 2 O), 12mmol ferrous sulfate heptahydrate (FeSO 4 7H 2 O), 8 mmol manganese sulfate monohydrate (MnSO 4 ·H 2 O) and 0.2 mol sodium thiosulfate (Na 2 S 2 O 3 ·5H 2 (0) was dissolved in 50 mL of deionized water and ultrasonicated for 30 minutes to promote dissolution. Subsequently, the resulting solution was transferred to an electrolytic cell for subsequent use.

[0062] b. In the three-electrode system, 1×1 cm2 nickel foam was used as the working electrode and fixed, a silver chloride electrode was used as the reference electrode, a platinum electrode was used as the counter electrode, and the electrolyte was the above-prepared solution. During the experiment, the light intensity was set to AM 1.5G, the constant voltage was maintained at -0.3V, the electrodeposition process was maintained for 0.5 minutes, and after light-assisted electrodeposition, deionized water was used to thoroughly wash to remove surface impurities, and finally vacuum dried to obtain a medium-high entropy metal compound nanostructure self-supporting material.

[0063] Comparative Example 1

[0064] The bare nickel foam pretreated in Example 2 was used directly as Comparative Example 1 without preparing the electrolyte of step b.

[0065] Comparative Example 2

[0066] The synthesized medium-high entropy catalyst was directly used as Comparative Example 2 by removing the xenon lamp AM 1.5G light source condition in Example 2 and keeping other conditions unchanged.

[0067] Comparative Example 3

[0068] The medium-high entropy catalyst synthesized under the conditions of removing manganese sulfate monohydrate in Example 2 was directly used as Comparative Example 3.

[0069] Figure 1 Scanning electron microscope (SEM) analysis was performed on the medium-high entropy catalyst sample prepared in Example 2. It can be seen that there is a thin film structure on the surface, and it can be observed that it is uniformly loaded on the nickel foam substrate.

[0070] Figure 2 The medium-high entropy catalyst sample prepared in Example 2 was subjected to projection scanning electron microscopy (TEM) analysis. It can be seen that a nanosheet structure grows on the surface of the medium-high entropy compound after the test, and the smooth surface becomes rough, which is conducive to exposing more active sites.

[0071] Figure 3 and Figure 4 The linear scanning polarization curves and Tafel slopes of the medium-high entropy compound of Example 2 and the blank nickel foam of Comparative Example 1 in 1M KOH are shown. Example 2 (248 mV) is significantly better than the blank nickel foam obtained in Comparative Example 1 (389 mV).

[0072] Figure 5 The linear scanning polarization curves of the medium-high entropy compounds in Example 2 and Comparative Example 2 with and without additional light sources, 100 mA cm -2 The current density of Example 2 (248 mV) is significantly better than that of Comparative Example 2 (385 mV), and is increased by 137 mV under the condition of additional light source.

[0073] Figure 6 and Figure 7 The linear sweep voltammetric curves and Tafel slopes of the medium-high entropy compound of Example 2 under 1 M KOH, 1 M KOH + 0.5 M NaCl and 1 M KOH + seawater conditions are shown in Figure 2. -2 The overpotentials at the current densities are 248 mV, 252 mV, and 292 mV, respectively.

[0074] Figure 8 and Fig. 9The corrosion resistance of the medium-high entropy compounds prepared in Example 2 and Comparative Example 3 as oxygen reaction catalysts under different electrolyte conditions can be seen from the Tafel curve. The corrosion voltages of Example 2 under 1M KOH, 1M KOH+0.5M NaCl and 1M KOH+seawater conditions are 1.18V, 1.11V, 0.92V, respectively, and the corrosion currents are 5.9μA, 7.22μA and 9.19μA, respectively. The corrosion voltages of Comparative Example 3 under 1M KOH, 1M KOH+0.5M NaCl and 1M KOH+seawater conditions are 1.03V, 1.01V, 0.92V, respectively, and the corrosion currents are 15.54μA, 22.4μA and 70.12μA, respectively. It can be seen from the above that the medium-high entropy catalyst has high corrosion resistance under different electrolyte conditions.

[0075] Fig.10 and Fig.11 The linear sweep voltammetric curve and chronopotentiometry curve of the medium-high entropy compound prepared in Example 1 as an oxygen reaction catalyst in an electrolytic cell can reach 1A cm at a voltage of 2V. -2 The current density can reach 10 ...

[0076] Fig.12 X-ray photoelectron spectroscopy (XPS) analysis was performed on the sample of Example 2. Before the test, the peak of O was mainly composed of adsorbed water (533.1 eV), M-OH (530.94 eV) and MO (529.74 eV). After the test, the morphology was reconstructed. Through XPS, it can be observed that the intensity of adsorbed water decreased, and the intensity of M-OH and MO peaks increased.

[0077] Fig.13 Raman spectroscopy (Raman) analysis was performed on the sample of Example 2, and it was found that the characteristic peak of NiOOH appeared in the medium-high entropy compound after the test, which was consistent with the XPS data, thereby further verifying that the surface had been reconstructed.

[0078] It exhibits excellent corrosion resistance in the harsh seawater electrolysis environment. Specifically, the material exhibits a large corrosion voltage and a small corrosion current under the conditions of seawater electrolysis. This unique electrochemical performance index not only effectively inhibits the corrosion rate, but also greatly extends the service life of the material. These excellent performance characteristics make it have broad application prospects in the fields of marine engineering, seawater electrolysis equipment, etc.

Claims

1. A method for preparing a medium-high entropy self-supporting oxygen reaction catalyst synthesized by light-assisted electrodeposition at room temperature, comprising the following steps: a. First, cut the nickel foam, put it into acetone solution to remove the oil stains on the surface by ultrasonic, rinse it with deionized water several times to remove the acetone on the surface, and then use dilute hydrochloric acid to ultrasonically remove the surface oxide layer, take out the nickel foam and rinse it to neutral, and vacuum dry it at 60℃ for 12h for later use; b. Dissolve different metal salts and reducing agents in deionized water by ultrasonication for 30 minutes, and pour the prepared solution into the electrolytic cell; c. In a three-electrode system, nickel foam is used as the working electrode, a silver chloride electrode is used as the reference electrode, and a platinum electrode is used as the counter electrode. The electrolyte is the solution described in step b. During the experiment, electrodeposition is carried out under certain light intensity and constant voltage conditions. The deposited nickel foam is washed and dried to obtain a medium-high entropy self-supporting oxygen reaction catalyst.

2. The method for preparing a medium-high entropy self-supporting oxygen reaction catalyst synthesized by light-assisted electrodeposition at room temperature according to claim 1, characterized in that: The metal salt includes several of iron sulfate, manganese sulfate, nitrate, sulfate or acetate of cobalt, nickel, zinc, vanadium and copper, and the reducing agent includes one of hydrazine hydrate, sodium borohydride, sodium sulfite, sodium thiosulfate, sodium borate and potassium tetraborate.

3. The method for preparing a medium-high entropy self-supporting oxygen reaction catalyst synthesized by light-assisted electrodeposition at room temperature according to claim 2, characterized in that: The amount of the metal salt substance is 20-52 mmol, the amount of the reducing agent substance is 0.3-2 mol, and the amount of deionized water is 50-100 mL.

4. The method for preparing a medium-high entropy self-supporting oxygen reaction catalyst synthesized by light-assisted electrodeposition at room temperature according to claim 3, characterized in that: The metal salt is 8mmol of cobalt nitrate hexahydrate, 8mmol of nickel sulfate hexahydrate, 8mmol of manganese sulfate monohydrate, 20mmol of ferrous sulfate heptahydrate, and 8mmol of zinc acetate dihydrate; the reducing agent is 0.3mol of potassium tetraborate; and the deionized water is 100mL.

5. The method for preparing a medium-high entropy self-supporting oxygen reaction catalyst synthesized by light-assisted electrodeposition at room temperature according to claim 1, characterized in that: The light intensity is AM 1.5G.

6. The method for preparing a medium-high entropy self-supporting oxygen reaction catalyst synthesized by light-assisted electrodeposition at room temperature according to claim 1, characterized in that: The three-electrode system is an experimental device in electrochemical research, which consists of three main parts: a working electrode (WE), a counter electrode (CE) and a reference electrode (RE). The constant voltage is set to -0.3 to 1V, and the electrodeposition process is maintained for 0.5 to 120 minutes.

7. The method for preparing a medium-high entropy self-supporting oxygen reaction catalyst synthesized by light-assisted electrodeposition at room temperature according to claim 1, characterized in that: The washing and drying operation in step c is to rinse the deposited nickel foam and put it into a vacuum drying oven and dry it at 60° C. for 12 hours.

8. Use of a medium-high entropy self-supporting oxygen reaction catalyst synthesized by light-assisted electrodeposition at room temperature as claimed in any one of claims 1 to 7, characterized in that: Including its application in seawater electrolysis and offshore engineering.

9. Use of a medium-high entropy self-supporting oxygen reaction catalyst synthesized by light-assisted electrodeposition at room temperature as claimed in any one of claims 1 to 7, characterized in that: include: (1) Electrocatalytic oxygen evolution reaction: The prepared medium-high entropy self-supporting catalyst was used as the working electrode, the platinum sheet as the counter electrode, and silver chloride as the reference electrode to carry out OER test in 1 M KOH electrolyte solution. (2) Electrochemical performance test: The OER performance was evaluated by linear sweep voltammetry and AEM electrolyzer device test. In addition, the stability and durability of the catalyst were evaluated by Tafel plot and chronopotentiometry, and its catalytic active sites were studied by XPS and Raman.

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