An anode oxygen evolution reaction catalyst, a preparation method and application thereof

Abstract

This invention discloses an anodic oxygen evolution reaction (OER) catalyst, its preparation method, and its applications. The preparation method includes the following steps: obtaining a heterostructure of a bimetallic hydroxide and iron trisulfide phosphide; and subjecting the bimetallic hydroxide and iron trisulfide phosphide heterostructure to hydrogen plasma treatment using a hydrogen-argon mixed gas as the plasma generating gas to obtain the anodic OER catalyst H-Pla-LDH@FePS3. The catalyst prepared by this invention can solve the technical problems of poor electron conduction of LDH and easy oxidation to peroxides during the OER anodic reaction in the prior art. In addition, first-principles calculations show that this technology can adjust the catalyst's weak adsorption and desorption capacity for reaction intermediates, thereby reducing overpotential and improving catalytic activity.

Description

Technical Field

[0001] This invention belongs to the field of oxygen evolution catalyst technology for water electrolysis, and specifically relates to an anodic oxygen evolution reaction catalyst, its preparation method, and its application. Background Technology

[0002] With societal development, human demand for energy is increasing, but the growing scarcity of traditional fossil fuels makes finding alternatives imperative. Hydrogen (H2) is one of the most ideal alternatives to traditional fossil fuels, possessing high energy density (142 MJ / kg⁻¹). -1 Hydrogen, with its advantages of wide applicability (fuel and important industrial raw material) and clean, pollution-free operation (water is the only byproduct), is considered one of the most promising clean energy sources of the 21st century. Water electrolysis is a sustainable and efficient method for obtaining hydrogen energy. Commercially available water electrolysis catalysts are still made of precious metals, such as Pt and RuO2 / IrO2, but these precious metal-based catalysts are limited by their scarcity and high cost. Therefore, developing low-cost, highly active, and highly stable electrocatalysts is an urgent problem to be solved.

[0003] Electrolysis catalysts are classified into cathode hydrogen evolution reaction catalysts (HER) and anode oxygen evolution reaction catalysts (OER); among them, OER catalysts include noble metal-based catalysts and transition metal-based catalysts.

[0004] RuO2 and IrO2, with their rutile structures, are typical noble metal-based OER catalysts, exhibiting excellent OER catalytic activity in both acidic and alkaline media, with their adsorption enthalpy mainly distributed at the top of the "volcano diagram." However, under prolonged high-potential electrolysis, RuO2 and IrO2 will form highly oxidized states (RuO2 and IrO2). 8+ O4 and (Ir) 6+ O3 then dissolves in the electrolyte solution, thereby reducing its catalytic activity and exhibiting instability during long-term operation; in addition, the high price and scarcity of precious metals and catalysts severely limit their large-scale industrial production and application.

[0005] Transition metal-based catalysts are compounds containing elements such as Fe, Co, Ni, and W, including their phosphides, nitrides, sulfides, carbides, oxides, and hydroxides. Compared to the aforementioned commercially available noble metal catalysts, transition metal-based catalysts have advantages such as abundant resources and low cost, and thus hold great promise for scientific research. Transition metal hybrid materials are highly attractive for electrocatalytic applications due to their abundant raw materials, diverse structures, and relatively high corrosion resistance in alkaline media. They are expected to replace existing noble metal-based electrocatalysts for electrochemical hydrogen evolution (HER) and oxygen evolution (OER) reactions. Among them, bimetallic hydroxides (LDHs) are a type of two-dimensional nanolayered material. The layers are composed of positively charged metal cations, and the spaces between the layers are composed of anions and water molecules. In the OER process, they are oxidized to higher valence hydroxyl oxides, which are highly favored in the OER field, changing the disadvantages of expensive and scarce noble metal catalysts. However, this type of material is limited by the following aspects: (1) poor electron conduction; (2) easy to be oxidized to peroxides with low reactivity in the OER anodic reaction; (3) high water dissociation energy and large overpotential caused by uncoordinated adsorption and desorption of reaction intermediates (H, OH, OOH and O). In summary, there is an urgent need for a new anodic oxygen evolution reaction catalyst based on bimetallic hydroxides. Summary of the Invention

[0006] The purpose of this invention is to provide an anodic oxygen evolution reaction (OER) catalyst, its preparation method, and its application, to solve one or more of the aforementioned technical problems. The catalyst prepared by the method of this invention can solve the technical problems of poor electron conduction of LDH and easy oxidation to peroxides during the OER anodic reaction in the prior art. Furthermore, first-principles calculations show that this technology can adjust the catalyst's weak adsorption and desorption capabilities for reaction intermediates (H, OH, OOH, and O), thereby reducing overpotential and improving catalytic activity.

[0007] To achieve the above objectives, the present invention adopts the following technical solution:

[0008] The present invention provides a method for preparing an anodic oxygen evolution reaction catalyst, comprising the following steps:

[0009] Obtain the heterostructure of bimetallic hydroxide and iron trisulfide phosphide;

[0010] Using a hydrogen-argon mixture as the plasma generating gas, the heterostructure of the bimetallic hydroxide and iron trisulfide phosphide is subjected to hydrogen plasma treatment to obtain the anodic oxygen evolution reaction catalyst H-Pla-LDH@FePS3. During the hydrogen plasma treatment, the reducing hydrogen plasma transfers electrons to the metal element, causing the metal element to generate a new valence state. The hydrogen plasma that loses electrons becomes hydrogen protons, which combine with the surface hydroxyl groups to generate water molecules.

[0011] A further improvement of the preparation method of the present invention is that the reaction time of the hydrogen plasma treatment is set to 5s to 500s, and the reaction power is 200W to 400W.

[0012] A further improvement to the preparation method of the present invention is that the bimetal in the heterostructure of the bimetallic hydroxide and iron trisulfide phosphide is two metals selected from cobalt, nickel and iron.

[0013] A further improvement to the preparation method of the present invention is that the step of obtaining the heterostructure of bimetallic hydroxide and iron trisulfide phosphide specifically includes:

[0014] A heterostructure of bimetallic hydroxide and iron trisulfide phosphide was prepared by coprecipitation method.

[0015] A further improvement to the preparation method of the present invention is that the step of preparing the heterostructure of bimetallic hydroxide and iron trisulfide phosphide by co-precipitation specifically includes:

[0016] Step 1: Prepare a mixed aqueous solution of cobalt metal salt and nickel metal salt; wherein the molar ratio of cobalt metal salt to nickel metal salt in the mixed aqueous solution is (4~1):1;

[0017] Step 2: Obtain the iron trisulfide phosphide suspension and place it into the mixed aqueous solution obtained in Step 1, stir until the mixture is uniform, and obtain a mixed solution; wherein, in the iron trisulfide phosphide suspension, the suspended matter is FePS3 nanosheets and the solvent is deionized water;

[0018] Step 3: Under stirring conditions, ammonia water is added dropwise to the mixed solution obtained in step 2. After the addition is complete, stirring conditions are maintained and the reaction is allowed to proceed for a preset time. After the reaction is completed, the precipitate is obtained by centrifugation and washed repeatedly with deionized water and ethanol, and then dried to obtain a heterostructure of bimetallic hydroxide and iron trisulfide phosphide.

[0019] A further improvement of the preparation method of the present invention is that, in step 1, the cobalt metal salt is cobalt sulfate, cobalt chloride, or cobalt nitrate; and the nickel metal salt is nickel sulfate, nickel chloride, or nickel nitrate.

[0020] A further improvement of the preparation method of the present invention is that, in step 3, the stirring conditions are maintained at 500 rpm / min to 2000 rpm / min, and the preset time is 0.5 min to 15 min.

[0021] The anodic oxygen evolution reaction catalyst prepared by any of the above-described preparation methods provided by this invention.

[0022] The present invention provides an application of an anodic oxygen evolution reaction catalyst, which is used as an anodic oxygen evolution reaction catalyst in the process of water electrolysis.

[0023] In this invention, when preparing the anodic oxygen evolution reaction catalyst, the bimetallic compound in the bimetallic hydroxide and iron trisulfide phosphide heterostructure is cobalt and nickel;

[0024] At 10mA cm -2 At a current density of [value missing], the overpotential and Tafel slope of the anolyte oxygen evolution reaction catalyst can reach 256 mV and 75 mV, respectively. -1 .

[0025] Compared with the prior art, the present invention has the following beneficial effects:

[0026] In the preparation method provided by this invention, the reduction effect of hydrogen plasma during the hydrogen plasma treatment process generates new valence state metal elements, which cause a redistribution of electronic states on the surface of double metal hydroxide (LDH) nanosheets, thereby creating defects and improving the surface state of the LDH nanosheets (the defect states of the new valence state metals are formed on the LDH surface, which can be confirmed by X-ray photoelectron spectroscopy (XPS)). The above-mentioned electronic regulation effect can enhance the electronic conductivity of the catalyst and improve its electrical conductivity. The new valence state metal elements will regulate the oxidation process of the catalyst in the OER reaction, avoiding oxidation into unfavorable peroxides and maintaining more active states of hydroxyl oxides (specifically, this can be confirmed by in-situ Raman characterization). Furthermore, the increased catalytic activity will inevitably lead to an increase in the number of defect states on the catalyst surface due to the emergence of other new valence states. First-principles calculations show that the presence of these defect states can regulate the adsorption and desorption capacity of the catalyst for reaction intermediates (H, OH, OOH, and O), thereby reducing the overpotential. In addition, defects are often considered beneficial factors in OER electrocatalysis because defect engineering can be used to modulate the electronic structure of materials, thereby enriching the active or adsorption sites and promoting charge transfer / separation. During the introduction of defects, atoms separate from the material's crystal lattice, and the chemical environment surrounding these atoms changes accordingly, leading to modification of the electronic structure. This modification of the surface electronic structure can regulate the adsorption energy of catalytic reaction intermediates on the catalyst surface and promote interfacial charge transfer between the electrolyte and the electrode, thus improving the electrocatalytic activity of the material.

[0027] This invention employs short-time hydrogen plasma treatment, after which the treated material is directly used as an electrocatalytic material, thus shortening the surface modification treatment time. Specifically, by controlling the reaction time and reaction power, the degree of hydrogen plasma treatment can be controlled, obtaining samples with different treatment degrees. Generally, higher reaction power and longer reaction time generate more defect states of new valence metal elements, thus improving the catalytic effect. However, with prolonged reaction time and increased reaction power, the microstructure of LDH is damaged, leading to LDH ablation and detachment (exemplarily, as shown in the accompanying drawings). Figure 3 (as shown), thereby reducing its electrocatalytic performance.

[0028] The hydrogen plasma-treated LDH@FePS3 of this invention, used as an electrocatalyst material in the OER reaction process, exhibits a considerably high level of electrocatalytic activity; among which, the linear sweep voltammetry curve ( Figure 7 (a) and Tafel curve ( Figure 7 (b) indicates that at 10 mA cm -2At current densities of [value missing], its overpotential and Tafel slope can reach 256 mV and 75 mV, respectively. -1 This significantly improves the electrocatalytic activity of bimetallic hydroxides. Furthermore, the electrode material of this invention exhibits almost no change in overpotential after a 24-hour stability test, demonstrating remarkably high operational stability. This is primarily because during hydrogen plasma treatment, the reducing hydrogen plasma reacts with the hydroxyl groups (-OH) on the surface of the bimetallic hydroxide nanosheets to produce water molecules (H2O), thereby reducing some metal elements and generating new valence states. The reduction of defective hydroxyl groups (-OH) also exposes internal metal atoms, revealing more active sites. Secondly, the generation of defective states can also cause changes in the surrounding chemical environment, achieving electronic regulation and redistributing electrons in LDH, further enhancing the OER catalytic activity.

[0029] Further illustratively, in conjunction with Example 1, the test results of Example 1 show that the treated electrocatalyst exhibits changes such as reduced overpotential, reduced EIS impedance, reduced Tafel slope, and increased electrochemical active area. This indicates that hydrogen plasma treatment plays a role in improving the intrinsic activity of the material, enhancing electronic conductivity, and increasing the electrochemical active surface area. In addition, in-situ Raman spectroscopy reveals a significant regulatory effect of defect states on the oxidation process. First-principles calculations demonstrate the adsorption and desorption capabilities of defect states for reaction intermediates (H, OH, OOH, and O), providing a theoretical explanation for the reduction in overpotential. Attached Figure Description

[0030] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art are briefly introduced below; obviously, the drawings described below are some embodiments of the present invention, and those skilled in the art can obtain other drawings based on these drawings without creative effort.

[0031] Figure 1 This is a schematic flowchart of a method for preparing an anode oxygen evolution reaction catalyst provided in an embodiment of the present invention;

[0032] Figure 2 This is a scanning electron microscope (SEM) schematic diagram of the hydrogen plasma-treated bimetallic hydroxide and iron trisulfide phosphide heterostructure (H-Pla-LDH@FePS3) prepared in Example 1 of this invention; wherein, Figure 2 (a) is a schematic diagram of a scanned image taken with a 2-micrometer scale. Figure 2 (b) is a schematic diagram of a scanned image taken at a 400-nanometer scale.

[0033] Figure 3This is a scanning electron microscope (SEM) schematic diagram of the hydrogen plasma-treated bimetallic hydroxide and iron trisulfide phosphide heterostructure (H-Pla-LDH@FePS3) prepared at different reaction times (5s, 10s, 20s, 100s, 500s) in Example 1 of the present invention.

[0034] Figure 4 This is an XRD characterization diagram of the heterostructure of bimetallic hydroxide and iron trisulfide phosphide (LDH@FePS3) prepared in Example 1 of the present invention; further illustrative, Figure 4 The standard PDF cards for LDH and FePS3 are also provided in the document;

[0035] Figure 5 These are transmission electron microscope (TEM) images of the hydrogen plasma-treated bimetallic hydroxide and iron trisulfide phosphide heterostructure (H-Pla-LDH@FePS3) prepared in Example 1 of this invention; wherein, Figure 5 (a) is a schematic diagram of a TEM image. Figure 5 (b) is a schematic diagram of a high-resolution TEM image;

[0036] Figure 6 This is an XPS characterization of the hydrogen plasma-treated bimetallic hydroxide and iron trisulfide phosphide heterostructure (H-Pla-LDH@FePS3) and the untreated bimetallic hydroxide and iron trisulfide phosphide heterostructure (LDH@FePS3) prepared in Example 1 of this invention; wherein, Figure 6 (a) is a schematic diagram of the 2p fine spectrum of Ni. Figure 6 (b) is a schematic diagram of the 2p fine spectrum of Co.

[0037] Figure 7 This is a schematic diagram illustrating the electrochemical performance of the hydrogen plasma-treated bimetallic hydroxide and iron trisulfide phosphide heterostructure (H-Pla-LDH@FePS3) and the untreated bimetallic hydroxide and iron trisulfide phosphide heterostructure (LDH@FePS3) in electrochemical testing, as shown in Example 1 of this invention. Figure 7 (a) is a schematic diagram of the LSV curve. Figure 7 (b) is a schematic diagram of the Tafel slope curve;

[0038] Figure 8 This is a schematic diagram of the electrochemical impedance spectroscopy of the hydrogen plasma-treated bimetallic hydroxide and iron trisulfide phosphide heterostructure (H-Pla-LDH@FePS3) and the untreated bimetallic hydroxide and iron trisulfide phosphide heterostructure (LDH@FePS3) in the electrochemical test of Example 1 of the present invention.

[0039] Figure 9This is a schematic diagram of the ECSA fitting curves in electrochemical testing of the hydrogen plasma-treated bimetallic hydroxide and iron trisulfide phosphide heterostructure (H-Pla-LDH@FePS3) and the untreated bimetallic hydroxide and iron trisulfide phosphide heterostructure (LDH@FePS3) in Example 1 of this invention.

[0040] Figure 10 In Example 1 of this invention, the hydrogen plasma-treated bimetallic hydroxide and iron trisulfide phosphide heterostructure (H-Pla-LDH@FePS3) were prepared at 10 mA cm⁻¹ -2 Schematic diagram of stability performance under current density;

[0041] Figure 11 This refers to the in-situ Raman characterization of the hydrogen plasma-treated bimetallic hydroxide and iron trisulfide phosphide heterostructure (H-Pla-LDH@FePS3) and the untreated bimetallic hydroxide and iron trisulfide phosphide heterostructure (LDH@FePS3) in the OER oxidation process, as described in Example 1 of this invention. Figure 11 (a) shows a schematic diagram of the in-situ Raman characterization of H-Pla-LDH@FePS3. Figure 11 (b) is a schematic diagram of the in-situ Raman characterization of LDH@FePS3;

[0042] Figure 12 This is a schematic diagram of the OER reaction steps for the adsorption capacity of the prepared hydrogen plasma-treated bimetallic hydroxide and iron trisulfide phosphide heterostructure (H-Pla-LDH@FePS3) and the untreated bimetallic hydroxide and iron trisulfide phosphide heterostructure (LDH@FePS3) to the intermediate product, calculated using first-principles calculations (DFT). Figure 12 (a) is a schematic diagram of the OER reaction steps of H-Pla-LDH@FePS3. Figure 12 (b) is a schematic diagram of the OER reaction steps of LDH@FePS3;

[0043] Figure 13 This is a schematic optical photograph of the hydrogen plasma-treated bimetallic hydroxide and iron trisulfide phosphide heterostructure (H-Pla-LDH@FePS3) and the untreated bimetallic hydroxide and iron trisulfide phosphide heterostructure (LDH@FePS3) prepared in Example 1 of this invention; wherein, Figure 13 (a) is a schematic diagram of the optical image of LDH@FePS3. Figure 13 (b) is a schematic diagram of the optical image of H-Pla-LDH@FePS3. Detailed Implementation

[0044] The present invention will be further illustrated below with reference to specific embodiments. It should be understood that these embodiments are for illustrative purposes only and are not intended to limit the scope of protection of the present invention.

[0045] Please see Figure 1 The present invention provides a method for preparing an anode oxygen evolution reaction catalyst, comprising the following steps:

[0046] Step 1: Obtain the heterostructure of bimetallic hydroxide and iron trisulfide phosphide;

[0047] Step 2: Using a hydrogen-argon mixed gas as the plasma generating gas, the heterostructure of the bimetallic hydroxide and iron trisulfide phosphide is subjected to hydrogen plasma treatment to obtain the anodic oxygen evolution reaction catalyst H-Pla-LDH@FePS3. During the hydrogen plasma treatment, the reducing hydrogen plasma transfers electrons to the metal element, causing the metal element to generate a new valence state. The hydrogen plasma that loses electrons becomes hydrogen protons, which combine with the surface hydroxyl groups to generate water molecules. The bimetallic compound in the bimetallic hydroxide and iron trisulfide phosphide heterostructure consists of two metals selected from cobalt, nickel, and iron.

[0048] The catalyst prepared by the method provided in this invention can solve the technical problems of poor electron conduction of LDH and easy oxidation to peroxides during the OER anode reaction in the prior art. First-principles calculations show that this technology can adjust the catalyst's weak adsorption and desorption capacity for reaction intermediates (H, OH, OOH and O), thereby reducing overpotential and improving catalytic activity.

[0049] The principle of the technical solution provided in this invention is mainly that the reduction effect of hydrogen plasma during the hydrogen plasma treatment process generates metal elements with new valence states, which cause a redistribution of electronic states on the surface of LDH nanosheets, thereby creating defects and improving the surface state of LDH nanosheets. The above-mentioned electronic regulation effect can enhance the electronic conductivity of the catalyst and improve its electrical conductivity. The new valence metal elements will regulate the oxidation process of the catalyst in the OER reaction process, avoiding oxidation into unfavorable peroxides and maintaining more active states of hydroxyl oxides.

[0050] The present invention provides a method for preparing an anodic oxygen evolution reaction catalyst, which specifically includes the following steps:

[0051] Using a hydrogen-argon mixture as the plasma generating gas, a pre-acquired dry bimetallic hydroxide and iron trisulfide phosphide heterostructure is subjected to hydrogen plasma treatment. Within the plasma treatment chamber, the reducing hydrogen plasma transfers electrons to the metal element, causing it to acquire a new valence state, i.e., a defect state. The hydrogen plasma, having lost electrons, becomes hydrogen protons, which combine with surface hydroxyl groups (-OH) to form water molecules, which then escape from the surface in the vacuum chamber. At this point, a defect state of the new valence metal is formed on the LDH surface, which can be confirmed by X-ray electron diffraction (XPS). For example... Figure 6 The fine 2p electron layer spectra of Ni and Co elements in H-Pla-LDH@FePS3 and LDH@FePS3 in Example 1 are shown. Figure 6 The (a)-LDH@FePS3 in Example 1 is the 2p fine spectrum of Ni in LDH@FePS3 without hydrogen plasma treatment. 855.69 eV and 873.73 eV represent the values ​​of Ni. 2+ The characteristic peaks at 856.56 eV and 874.67 eV are for Ni. 3+ The characteristic peaks at 861.45 eV and 879.22 eV are two satellite peaks of Ni, and characteristic peaks of Ni3+ and Ni2+ can be observed. Figure 6 The 2p fine spectrum of Co in LDH@FePS3 in Example 1 (b) is shown, without hydrogen plasma treatment. 782.73 eV and 798.44 eV represent the values ​​of Co. 2+ The characteristic peaks at 780.90 eV and 796.69 eV are for Co. 3+ The characteristic peaks, 786.85 eV and 802.63 eV, are two satellite peaks of Co, and Co can be observed. 3+ and Co 2+ The characteristic peaks; however, in the 2p fine spectra of Ni and Co elements in Pla-H-LDH@FePS3 after hydrogen plasma treatment (Figure (a)-H-Pla-LDH@FePS3 and Figure (b)-H-Pla-LDH@FePS3), new peaks were observed in the direction of lower binding energy, which were identified as Ni. δ+ and Co λ+ This means that a new valence state of the metallic element, Ni, has emerged. δ+ and Co λ+ In LDH composed mainly of divalent and trivalent metal elements, the uniform chemical environment is disrupted. The presence of these elements is a defect state for the complete and ordered crystal structure, causing a redistribution of electronic states and changing the surface chemical environment, thereby enabling the regulation of the surface state of LDH@FePS3.

[0052] In specific and exemplary embodiments of this invention, the reaction time for hydrogen plasma treatment is set to 5 s–500 s, and the reaction power is 200 W–400 W. By controlling the reaction time and reaction power, the degree of hydrogen plasma treatment can be controlled, resulting in samples with different degrees of treatment. Further explanation: a higher reaction power and a longer reaction time generate more defect states of new valence metal elements, thus improving the catalytic effect. However, with prolonged reaction time and increased reaction power, the microstructure of LDH is damaged, leading to LDH ablation and detachment (exemplarily, as shown in the accompanying drawings). Figure 3 (as shown), thereby reducing its electrocatalytic performance.

[0053] In a specific exemplary embodiment of the present invention, the method for obtaining the heterostructure of bimetallic hydroxide and iron trisulfide phosphide is as follows: The heterostructure of bimetallic hydroxide and iron trisulfide phosphide (LDH@FePS3) is prepared by co-precipitation. Further illustratively, the steps for preparing the heterostructure of bimetallic hydroxide and iron trisulfide phosphide (LDH@FePS3) by co-precipitation specifically include:

[0054] Prepare a mixed aqueous solution of salt A and salt B; wherein the molar ratio of salt A to salt B in the mixed aqueous solution is (4-1):1; in addition, salt A can be a cobalt metal salt such as cobalt sulfate, cobalt chloride, or cobalt nitrate; and salt B can be a nickel metal salt such as nickel sulfate, nickel chloride, or nickel nitrate.

[0055] The pre-obtained iron trisulfide phosphide suspension (the suspension is FePS3 nanosheets, and the solvent is deionized water) is placed into the mixed aqueous solution prepared above, and stirred thoroughly until the mixture is homogeneous to obtain a homogeneous mixed solution.

[0056] Under stirring conditions, 0.1–5 ml of ammonia water (NH3 H2O) was added dropwise to the well-mixed solution. After the addition was complete, the stirring conditions were maintained (stirring speed of 500–2000 rpm / min) and the reaction was allowed to proceed for 0.5–15 min. After the reaction was completed, the precipitate was obtained by centrifugation and washed repeatedly with deionized water and ethanol, and then dried to obtain the heterostructure of bimetallic hydroxide and iron trisulfide phosphide (LDH@FePS3).

[0057] Specifically, as an example, cobalt sulfate hexahydrate (CoSO4 6H2O) and nickel sulfate hexahydrate (NiSO4 6H2O) are dissolved in 25 mL of deionized water at a molar ratio of 2:1 to prepare solution A; in solution A, Co... 2+ with Ni 2+The ratio is 2:1. Besides cobalt sulfate hexahydrate (CoSO4 6H2O) and nickel sulfate hexahydrate (NiSO4 6H2O), the nickel metal salts in the raw materials can be nickel sulfate (including its anhydrous salt (NiSO4), monohydrate (NiSO4 H2O), dihydrate (NiSO4 2H2O), tetrahydrate (NiSO4 4H2O), pentahydrate (NiSO4 5H2O), and heptahydrate (NiSO4 7H2O)), nickel nitrate (including its anhydrous salt (Ni(NO3)2), dihydrate (Ni(NO3)2 2H2O), tetrahydrate (Ni(NO3)2 4H2O), hexahydrate (Ni(NO3)2 6H2O), and nonahydrate (Ni(NO3)2 9H2O)) and nickel chloride (including its anhydrous salt (NiCl2), monohydrate (NiCl2 H2O), and dihydrate (NiCl2 9H2O)). For nickel metal salts, any one of the following can be used: cobalt sulfate (including its anhydrous salt (CoSO4), monohydrate (CoSO4 H2O), dihydrate (CoSO4 2H2O), tetrahydrate (CoSO4 4H2O), pentahydrate (CoSO4 5H2O), hexahydrate (CoSO4 6H2O), heptahydrate (CoSO4 7H2O), cobalt nitrate (including its anhydrous salt (Co(NO3)2), dihydrate (Co(NO3)2 2H2O), tetrahydrate (Co(NO3)2 4H2O), hexahydrate (Co(NO3)2 6H2O), and nonahydrate (Co(NO3)2 9H2O)), and cobalt chloride (CoCl2) (including its anhydrous salt (CoCl2) and monohydrate (CoCl2)). Any one of the following cobalt metal salts: (CoCl2 + H2O), dihydrate (CoCl2 + 2H2O), tetrahydrate (CoCl2 + 4H2O), hexahydrate (CoCl2 + 6H2O), etc.; 25 ml of iron trisulfide phosphide (FePS3) solution pre-obtained by electrochemical stripping method is mixed with solution A and stirred thoroughly until homogeneous. 0.1–1 ml of ammonia water (NH3 + H2O) is added dropwise to the homogeneous solution under stirring. After the addition is complete, the reaction is continued under stirring for 5 minutes. By controlling the amount of ammonia water added, heterostructures of bimetallic hydroxide and iron trisulfide phosphide (LDH@FePS3) with different loadings can be prepared.

[0058] The preparation method of this invention prepares an anodic oxygen evolution reaction catalyst, specifically H-Pla-LDH@FePS3, and the specific preparation steps are as follows:

[0059] A small amount of dry powder from the bimetallic hydroxide and iron trisulfide phosphide heterostructure (LDH@FePS3) prepared in the previous step was evenly spread in a ceramic boat. The ceramic boat was then placed in the reaction chamber of a plasma cleaner, using a hydrogen-argon mixture as the plasma generating gas. The reaction time was 5–500 s, and the reaction power was 200–400 W. After the reaction was completed, a sample with a black surface was obtained, and its optical photograph is shown below. Figure 13 As shown, where, Figure 13 (a) The sample in the middle is not treated with hydrogen plasma and appears blue. Figure 13 (b) shows the sample after hydrogen plasma treatment; the powder is black in color. Figure 3 The images are scanning electron microscope (SEM) images at different processing times with a power of 300W. It can be observed that the surface morphology of the samples processed for 5s and 10s is basically unchanged compared with the untreated samples, maintaining the integrity of the vertically grown NiCoLDH nanosheet structure and presenting a honeycomb structure. However, when the processing time is extended, the LDH nanosheets show obvious traces of ablation and detachment.

[0060] The electrochemical performance testing of the anodic oxygen evolution reaction catalyst prepared in this embodiment of the invention specifically includes the following steps:

[0061] The prepared H-Pla-LDH@FePS3 sample was mixed with a conductive agent (the conductive agent can be acetylene black, superconducting carbon black, Cabot carbon black, or other commonly used laboratory electrochemical testing conductive agents) at a weight ratio of 2–4:1. The mixture was then ground evenly in a grinding dish. The ground powder was then prepared into a slurry for electrochemical testing. The slurry preparation ratio can follow general electrochemical testing procedures, such as using isopropanol, ethanol, deionized water, and Nafion solution to prepare the slurry. No special requirements are needed. Subsequently, the prepared slurry was sonicated for 2–6 hours to ensure uniform dispersion.

[0062] The ultrasonically dispersed black slurry was pipetted onto a glassy carbon electrode in a total of 2–20 μl to form a black catalyst film. After thorough drying, electrochemical performance tests were performed in an alkaline electrolyte using an electrochemical workstation. These tests included, but were not limited to, cyclic voltammetry (CV), linear voltammetry (LSV), electrochemical impedance spectroscopy (EIS), electrochemical specific surface area (ECSA), and stability testing (IT). The test voltage range was 1.0–1.8 V vs RHE.

[0063] Example 1

[0064] This invention provides a method for preparing an anode oxygen evolution reaction catalyst, specifically including the following steps:

[0065] Step 1: Preparation of the bimetallic hydroxide and iron trisulfide phosphide heterostructure (LDH@FePS3) by coprecipitation method, including: dissolving cobalt sulfate hexahydrate (CoSO4 6H2O) and nickel sulfate hexahydrate (NiSO4 6H2O) in 25 mL of deionized water at a ratio of 2:1 to prepare solution A; mixing 25 mL of pre-exfoliated iron trisulfide phosphide (FePS3) solution with solution A and stirring thoroughly until homogeneous; adding 1 mL of ammonia water (NH3 H2O) dropwise at a constant speed of 1000 rpm / min, maintaining the speed constant and reacting for 5 min; after the reaction, washing the reaction product sequentially with deionized water and ethanol, and drying to obtain a blue-gray powder;

[0066] Step 2, hydrogen plasma treatment, includes: after drying the prepared bimetallic hydroxide and iron trisulfide phosphide heterostructure (LDH@FePS3), a small amount of dried powder is weighed and evenly spread in a ceramic boat, the ceramic boat is placed in the reaction chamber of the plasma cleaner, a hydrogen-argon mixture is used as the plasma generating gas, the reaction time is set to 10s, the reaction power is adjusted to 300W, and a sample with a black surface is obtained.

[0067] Step 3, preparation and testing of catalyst slurry, includes: drying the treated bimetallic hydroxide and iron trisulfide phosphide heterostructure (LDH@FePS3), mixing and grinding it with the conductive agent acetylene black at a mass ratio of 4:1, dissolving it in a solvent of isopropanol:deionized water:Nafion = 18:2:1, sonicating for 4 hours to prepare a uniform black slurry, and adding 2 μl dropwise to the glassy carbon electrode five times (10 μl each time) using a pipette. After thorough drying, electrochemical performance testing is performed using an Autolab electrochemical workstation, with a test voltage range of 1.0–1.8 V.

[0068] Please see Figure 2 , Figure 2 The image shows a scanning electron microscope (SEM) image of the hydrogen plasma-treated bimetallic hydroxide and iron trisulfide phosphide heterostructure (H-Pla-LDH@FePS3) prepared in Example 1. Figure 2 The two images show that the bimetallic NiCo hydroxide grows in a honeycomb pattern on the FePS3 surface, and the surface structure remains intact.

[0069] Please see Figure 3 , Figure 3Scanning electron microscope (SEM) images of the heterostructure of bimetallic hydroxide and iron trisulfide phosphide (H-Pla-LDH@FePS3) after hydrogen plasma treatment at different processing times (5s, 10s, 20s, 100s, and 500s) are shown. The images reveal that the LDH in samples treated for 5s and 10s retains its intact microstructure and honeycomb structure. However, with prolonged reaction time, the microstructure of the LDH is gradually destroyed, resulting in scanning electron microscopy (SEM) detachment. This is because during hydrogen plasma treatment, isostatic bombardment, prolonged high temperatures, and occasional electrical sparks all damage the structure of the surface LDH array.

[0070] Please see Figure 4 , Figure 4 The XRD characterization of the FePS3, bimetallic hydroxide, and bimetallic hydroxide-iron trisulfide heterostructure prepared in Example 1 is shown. Comparison with the standard PDF (LDH: PDF#22-0444 and FePS3 PDF#74-1501) cards shows that the diffraction peaks of LDH and FePS3 appear simultaneously in the PDF spectrum of LDH@FePS3, confirming the formation of the LDH@FePS3 heterostructure.

[0071] Please see Figure 5 , Figure 5 The image shown is a transmission electron microscope (TEM) image of the hydrogen plasma-treated metal hydroxide and iron trisulfide phosphide heterostructure (H-Pla-LDH@FePS3) prepared in Example 1. Figure 5 (a) The TEM image shows a honeycomb structure, with LDH nanosheets approximately 3 nm thick, confirming that the microstructure of LDH remains intact after hydrogen plasma treatment; through Figure 5 In the high-resolution TEM image (b), a clear 0.376 nm interplanar spacing can be seen, corresponding to the (002) plane of LDH; in addition, there are clear 0.24 nm and 0.23 nm lattice spacings, corresponding to the (112) and (201) planes of FePS3, respectively, confirming that the heterostructure still maintains its original crystal structure after hydrogen plasma treatment.

[0072] Please see Figure 6 , Figure 6 In (a), the 2p fine spectrum of Ni in LDH@FePS3 without hydrogen plasma treatment in Example 1 is shown, with 855.69 eV and 873.73 eV representing Ni. 2+ The characteristic peaks at 856.56 eV and 874.67 eV are for Ni. 3+ The characteristic peaks at 861.45 eV and 879.22 eV are two satellite peaks of Ni, indicating that Ni can be observed. 3+ and Ni 2+Characteristic peaks; Figure 6 In (b), the 2p fine spectrum of Co in LDH@FePS3 without hydrogen plasma treatment in Example 1 is shown, with 782.73 eV and 798.44 eV representing Co. 2+ The characteristic peaks at 780.90 eV and 796.69 eV are for Co. 3+ The characteristic peaks, 786.85 eV and 802.63 eV, are two satellite peaks of Co, and Co can be observed. 3+ and Co 2+ The characteristic peaks; and in the 2p fine spectra of Ni and Co elements in Pla-H-LDH@FePS3 after hydrogen plasma treatment (H-Pla-LDH@FePS3 in Figure (a) and H-Pla-LDH@FePS3 in Figure (b)), new peaks were observed in the direction of lower binding energy, which were identified as Ni. δ+ and Co λ+ This means that a new valence state of the metallic element, Ni, has emerged. δ+ and Co λ+ In LDH composed mainly of divalent and trivalent metal elements, the uniform chemical environment is disrupted. The presence of these elements is a defect state for the complete and ordered crystal structure, causing a redistribution of electronic states and changing the surface chemical environment, thereby enabling the regulation of the surface state of LDH@FePS3.

[0073] Please see Figure 7 , Figure 7 (a) shows the LSV curves of the hydrogen plasma-treated metal hydroxide and iron trisulfide phosphide heterostructure (H-Pla-LDH@FePS3) sample prepared in Example 1 and its control sample, tested on a glassy carbon electrode using Autolab; at a current density of 10 mA cm⁻¹ -2 The overpotential of FePS3 alone was 460 mV; the overpotential of NiCo-LDH alone was 310 mV; the overpotential of the metal hydroxide and iron trisulfide phosphide heterostructure (LDH@FePS3) was 298 mV; and the overpotential was reduced to 256 mV after hydrogen plasma treatment. This indicates that hydrogen plasma treatment greatly reduced the overpotential of the OER reaction. The reduction in overpotential is attributed to the surface treatment effect of hydrogen plasma on LDH during the hydrogen plasma treatment process, which exposed more active sites. Figure 7 (b) shows the Tafel curves of the plasma-treated metal hydroxide and iron trisulfide phosphide heterostructure (LDH@FePS3) sample prepared in Example 1 and its control sample, measured on a glassy carbon electrode using Autolab. The Tafel slope of FePS3 is 285 mV dec. -1 The Tafel slope of NiCo LDH is 155 mV dec.-1 After hydrogen plasma treatment, the Tafel slope decreased to 75 mV dec. -1 The decrease in overpotential and Tafel slope indicates that H-Pla-LDH@FePS3 has higher catalytic activity.

[0074] Please see Figure 8 , Figure 8 Electrochemical impedance spectroscopy (EIS) spectra of the hydrogen plasma-treated metal hydroxide and iron trisulfide phosphide heterostructure (H-Pla-LDH@FePS3) sample prepared in Example 1 and its control sample were measured on a glassy carbon electrode using Autolab. Figure 8 It can be observed that the impedance loop radius of the sample was significantly reduced after hydrogen plasma treatment, indicating that the electronic conductivity of H-Pla-LDH@FePS3 was significantly improved, and hydrogen plasma treatment can improve the electronic conductivity of the material.

[0075] Please see Figure 9 , Figure 9 The electrochemical specific surface area (ECSA) of the hydrogen plasma-treated metal hydroxide and iron trisulfide phosphide heterostructure (H-Pla-LDH@FePS3) sample prepared in Example 1 and its control sample were measured on a glassy carbon electrode using Autolab. The ECSA after hydrogen plasma treatment was 148.72 mF cm⁻¹. -2 The growth rate was 176.49 mFcm. -2 This indicates that hydrogen plasma treatment can increase the electrochemical specific surface area, and the increase in electrochemical specific surface area is a favorable factor for improving OER performance.

[0076] Please see Figure 10 , Figure 10 The stability curve of the hydrogen plasma-treated metal hydroxide and iron trisulfide phosphide heterostructure (H-Pla-LDH@FePS3) sample prepared in Example 1 was tested using an Autolab electrochemical workstation at a current density of 10 mA cm⁻¹. -2 The material exhibits stable performance under certain conditions. After 100 hours of continuous reaction, its current density did not change significantly, and the fluctuations in the curve were due to the influence of room temperature changes, which further demonstrates the stability of the material during operation.

[0077] Please see Figure 11 , Figure 11 In-situ Raman characterization of the hydrogen plasma-treated metal hydroxide and iron trisulfide phosphide heterostructure (H-Pla-LDH@FePS3) sample prepared for Example 1 and its control sample during the OER process; wherein, Figure 11 (a) Samples treated with hydrogen plasma (H-Pla-LDH@FePS3) were subjected to hydrogen plasma at 460 cm⁻¹.-1 There is a vibrational peak of Ni-OH at 520 cm⁻¹. -1 There is a Co-OH vibration peak at 680 cm⁻¹, which occurs when the voltage reaches 1.09 V. -1 A new monomorphic peak appears around the left and right edges, and its intensity gradually increases with increasing voltage. This peak is the monomorphic peak of Co-OOH, located at 500 cm⁻¹. -1 The peak at 520 cm⁻¹ also represents the vibration of Co-OOH. -1 The intensity of the Co-OH peak at 1.27V decreases with increasing voltage, indicating the conversion of Co-OH to Co-OOH. Ni-OH exhibits a similar conversion to NiOOH, with a peak intensity of 460 cm⁻¹ at 1.27V. -1 The Ni-OH peak essentially disappeared at 1.33V. Then, at 460cm⁻¹, the peak reappeared at 1.33V. -1 The peaks on the left and right sides reappeared and increased in intensity, indicating that Co-OOH began to convert to CoO2 as the voltage increased. Figure 11 (b) shows the in-situ Raman characterization of the untreated sample (LDH@FePS3). The conversion of Co-OH to Co-OOH can be observed at 1.15–1.33 V, but based on the intensity ratio, the amount of conversion is far less than that of the treated sample. Furthermore, only a 460 cm⁻¹ area can be observed at 1.39 V. -1 and 550cm -1 The peaks on the left and right, belonging to NiO2 and CoO2, indicate that NiCo is rapidly oxidized to peroxides after 1.33V. In the OER reaction, nickel hydroxide and cobalt hydroxide are beneficial phases for improving catalytic performance, while peroxides delay reaction kinetics, causing adverse effects. Therefore, the sample H-Pla-LDH@FePS3 generated after hydrogen plasma treatment can regulate the sample oxidation process in the OER reaction, generating more nickel hydroxide and cobalt hydroxide phases to participate in the reaction. Nickel hydroxide and cobalt hydroxide are beneficial phases for catalysis, thereby improving its catalytic performance.

[0078] Please see Figure 12 , Figure 12In the first-principles calculations of the adsorption energies of intermediate reactants during the OER process for hydrogen plasma-treated metal hydroxide and iron trisulfide phosphide heterostructure (H-Pla-LDH@FePS3) samples and their comparative samples, Ni and Co atoms were selected as active sites for calculation. As shown in the figure, the rate-determining step for untreated LDH@FePS3 is the third step, with a magnitude of 1.84 eV; after hydrogen plasma treatment, the rate-determining step for H-Pla-LDH@FePS3 is the first step, with a magnitude of 1.60 eV. The changes in the rate-determining step and adsorption energy indicate that the defect states of Ni and Co elements generated after hydrogen plasma treatment can coordinate the adsorption and desorption of reaction intermediates (H, OH, OOH, and O), reducing the rate-determining step and thus improving catalytic activity.

[0079] Example 2

[0080] The present invention provides a method for preparing an anode oxygen evolution reaction catalyst, comprising the following steps:

[0081] Obtain the heterostructure of bimetallic hydroxide and iron trisulfide phosphide;

[0082] Using a hydrogen-argon mixed gas as the plasma generating gas, the heterostructure of the bimetallic hydroxide and iron trisulfide phosphide is subjected to hydrogen plasma treatment to obtain the anodic oxygen evolution reaction catalyst H-Pla-LDH@FePS3. During the hydrogen plasma treatment, the hydrogen plasma with reducing effect transfers electrons to the metal element, causing the metal element to generate a new valence state. The hydrogen plasma that loses electrons becomes hydrogen protons, which combine with the hydroxyl groups on the surface to generate water molecules.

[0083] Wherein, the bimetal in the heterostructure of the bimetallic hydroxide and iron trisulfide phosphide is cobalt and nickel; the reaction time of the hydrogen plasma treatment is set to 5s, and the reaction power is 200W.

[0084] Example 3

[0085] The present invention provides a method for preparing an anode oxygen evolution reaction catalyst, comprising the following steps:

[0086] Obtain the heterostructure of bimetallic hydroxide and iron trisulfide phosphide;

[0087] Using a hydrogen-argon mixed gas as the plasma generating gas, the heterostructure of the bimetallic hydroxide and iron trisulfide phosphide is subjected to hydrogen plasma treatment to obtain the anodic oxygen evolution reaction catalyst H-Pla-LDH@FePS3. During the hydrogen plasma treatment, the hydrogen plasma with reducing effect transfers electrons to the metal element, causing the metal element to generate a new valence state. The hydrogen plasma that loses electrons becomes hydrogen protons, which combine with the hydroxyl groups on the surface to generate water molecules.

[0088] Wherein, the bimetal in the heterostructure of the bimetallic hydroxide and iron trisulfide phosphide is cobalt and iron; the reaction time of the hydrogen plasma treatment is set to 300s and the reaction power is 300W.

[0089] Example 4

[0090] The present invention provides a method for preparing an anode oxygen evolution reaction catalyst, comprising the following steps:

[0091] Obtain the heterostructure of bimetallic hydroxide and iron trisulfide phosphide;

[0092] Using a hydrogen-argon mixed gas as the plasma generating gas, the heterostructure of the bimetallic hydroxide and iron trisulfide phosphide is subjected to hydrogen plasma treatment to obtain the anodic oxygen evolution reaction catalyst H-Pla-LDH@FePS3. During the hydrogen plasma treatment, the hydrogen plasma with reducing effect transfers electrons to the metal element, causing the metal element to generate a new valence state. The hydrogen plasma that loses electrons becomes hydrogen protons, which combine with the hydroxyl groups on the surface to generate water molecules.

[0093] Wherein, the bimetal in the heterostructure of the bimetallic hydroxide and iron trisulfide phosphide is nickel and iron; the reaction time of the hydrogen plasma treatment is set to 500s and the reaction power is 400W.

[0094] Example 5

[0095] The present invention provides a method for preparing an anode oxygen evolution reaction catalyst, comprising the following steps:

[0096] Obtain the heterostructure of bimetallic hydroxide and iron trisulfide phosphide;

[0097] Using a hydrogen-argon mixed gas as the plasma generating gas, the heterostructure of the bimetallic hydroxide and iron trisulfide phosphide is subjected to hydrogen plasma treatment to obtain the anodic oxygen evolution reaction catalyst H-Pla-LDH@FePS3. During the hydrogen plasma treatment, the hydrogen plasma with reducing effect transfers electrons to the metal element, causing the metal element to generate a new valence state. The hydrogen plasma that loses electrons becomes hydrogen protons, which combine with the hydroxyl groups on the surface to generate water molecules.

[0098] The steps for preparing the heterostructure of bimetallic hydroxide and iron trisulfide phosphide using the co-precipitation method specifically include:

[0099] Step 1: Prepare a mixed aqueous solution of cobalt metal salt and nickel metal salt; wherein the molar ratio of cobalt metal salt to nickel metal salt in the mixed aqueous solution is 4:1;

[0100] Step 2: Obtain the iron trisulfide phosphide suspension and place it into the mixed aqueous solution obtained in Step 1, stir until the mixture is uniform, and obtain a mixed solution; wherein, in the iron trisulfide phosphide suspension, the suspended matter is FePS3 nanosheets and the solvent is deionized water;

[0101] Step 3: Under stirring conditions, ammonia water is added dropwise to the mixed solution obtained in step 2; after the addition is complete, stirring conditions are maintained and the reaction is allowed to proceed for a preset time; after the reaction is completed, the precipitate is obtained by centrifugation and washed repeatedly with deionized water and ethanol, and then dried to obtain a heterostructure of bimetallic hydroxide and iron trisulfide phosphide.

[0102] In step 1, the cobalt metal salt is cobalt sulfate; the nickel metal salt is nickel sulfate; in step 3, the step of maintaining stirring conditions and reacting for a preset time, the stirring conditions are 500 rpm / min, and the preset time is 0.5 min.

[0103] Example 6

[0104] The present invention provides a method for preparing an anode oxygen evolution reaction catalyst, comprising the following steps:

[0105] Obtain the heterostructure of bimetallic hydroxide and iron trisulfide phosphide;

[0106] Using a hydrogen-argon mixed gas as the plasma generating gas, the heterostructure of the bimetallic hydroxide and iron trisulfide phosphide is subjected to hydrogen plasma treatment to obtain the anodic oxygen evolution reaction catalyst H-Pla-LDH@FePS3. During the hydrogen plasma treatment, the hydrogen plasma with reducing effect transfers electrons to the metal element, causing the metal element to generate a new valence state. The hydrogen plasma that loses electrons becomes hydrogen protons, which combine with the hydroxyl groups on the surface to generate water molecules.

[0107] The steps for preparing the heterostructure of bimetallic hydroxide and iron trisulfide phosphide using the co-precipitation method specifically include:

[0108] Step 1: Prepare a mixed aqueous solution of cobalt metal salt and nickel metal salt; wherein the molar ratio of cobalt metal salt to nickel metal salt in the mixed aqueous solution is 2:1;

[0109] Step 2: Obtain the iron trisulfide phosphide suspension and place it into the mixed aqueous solution obtained in Step 1, stir until the mixture is uniform, and obtain a mixed solution; wherein, in the iron trisulfide phosphide suspension, the suspended matter is FePS3 nanosheets and the solvent is deionized water;

[0110] Step 3: Under stirring conditions, ammonia water is added dropwise to the mixed solution obtained in step 2; after the addition is complete, stirring conditions are maintained and the reaction is allowed to proceed for a preset time; after the reaction is completed, the precipitate is obtained by centrifugation and washed repeatedly with deionized water and ethanol, and then dried to obtain a heterostructure of bimetallic hydroxide and iron trisulfide phosphide.

[0111] In step 1, the cobalt metal salt is cobalt nitrate; the nickel metal salt is nickel chloride; in step 3, the step of maintaining stirring conditions and reacting for a preset time, the stirring conditions are 1000 rpm / min, and the preset time is 5 min.

[0112] Example 7

[0113] The present invention provides a method for preparing an anode oxygen evolution reaction catalyst, comprising the following steps:

[0114] Obtain the heterostructure of bimetallic hydroxide and iron trisulfide phosphide;

[0115] Using a hydrogen-argon mixed gas as the plasma generating gas, the heterostructure of the bimetallic hydroxide and iron trisulfide phosphide is subjected to hydrogen plasma treatment to obtain the anodic oxygen evolution reaction catalyst H-Pla-LDH@FePS3. During the hydrogen plasma treatment, the hydrogen plasma with reducing effect transfers electrons to the metal element, causing the metal element to generate a new valence state. The hydrogen plasma that loses electrons becomes hydrogen protons, which combine with the hydroxyl groups on the surface to generate water molecules.

[0116] The steps for preparing the heterostructure of bimetallic hydroxide and iron trisulfide phosphide using the co-precipitation method specifically include:

[0117] Step 1: Prepare a mixed aqueous solution of cobalt metal salt and nickel metal salt; wherein the molar ratio of cobalt metal salt to nickel metal salt in the mixed aqueous solution is 1:1;

[0118] Step 2: Obtain the iron trisulfide phosphide suspension and place it into the mixed aqueous solution obtained in Step 1, stir until the mixture is uniform, and obtain a mixed solution; wherein, in the iron trisulfide phosphide suspension, the suspended matter is FePS3 nanosheets and the solvent is deionized water;

[0119] Step 3: Under stirring conditions, ammonia water is added dropwise to the mixed solution obtained in step 2; after the addition is complete, stirring conditions are maintained and the reaction is allowed to proceed for a preset time; after the reaction is completed, the precipitate is obtained by centrifugation and washed repeatedly with deionized water and ethanol, and then dried to obtain a heterostructure of bimetallic hydroxide and iron trisulfide phosphide.

[0120] In step 1, the cobalt metal salt is cobalt chloride; the nickel metal salt is nickel nitrate; in step 3, the step of maintaining stirring conditions and reacting for a preset time, the stirring conditions are 2000 rpm / min, and the preset time is 15 min.

[0121] In summary, this invention specifically discloses the application of hydrogen plasma treatment of LDH@FePS3 heterostructures in water electrolysis catalysts. By utilizing hydrogen plasma treatment, the surface state of the heterostructure is altered, electron redistribution is achieved, more active sites are exposed, and better catalytic performance is achieved. This invention's method can utilize 10 mA cm- 2 The overpotential decreased from ~300mV to 256mV, and the Tafel slope was only 75mV dec. -1 This is primarily because during hydrogen plasma treatment, the hydrogen plasma reacts with the hydroxyl groups (-OH) on the surface of the bimetallic hydroxide nanosheets, exposing internal metal atoms and exhibiting more active sites. Secondly, the generation of defect vacancies successfully achieves electronic regulation, redistributing electrons within the LDH and further enhancing the OER catalytic activity. The treated electrocatalyst exhibits changes such as reduced overpotential, reduced EIS impedance, reduced Tafel slope, and increased electrochemical active area.

Claims

1. A method for preparing an anode oxygen evolution reaction catalyst, characterized in that, Includes the following steps: Obtain the heterostructure of bimetallic hydroxide and iron trisulfide phosphide; Using a hydrogen-argon mixed gas as the plasma generating gas, the heterostructure of the bimetallic hydroxide and iron trisulfide phosphide is subjected to hydrogen plasma treatment to obtain the anodic oxygen evolution reaction catalyst H-Pla-LDH@FePS3. During the hydrogen plasma treatment, the hydrogen plasma with reducing effect transfers electrons to the metal element, causing the metal element to generate a new valence state. The hydrogen plasma that loses electrons becomes hydrogen protons, which combine with the hydroxyl groups on the surface to generate water molecules. in, The reaction time for the hydrogen plasma treatment is set to 5s-500s, and the reaction power is 200W-400W. The bimetallic hydroxide and iron trisulfide phosphide heterostructure contains two metals selected from cobalt, nickel and iron. The steps for obtaining the heterostructure of bimetallic hydroxide and iron trisulfide phosphide specifically include: preparing the heterostructure of bimetallic hydroxide and iron trisulfide phosphide using a co-precipitation method.

2. The method for preparing an anodic oxygen evolution reaction catalyst according to claim 1, characterized in that, The steps for preparing the heterostructure of bimetallic hydroxide and iron trisulfide phosphide using the co-precipitation method specifically include: Step 1: Prepare a mixed aqueous solution of cobalt metal salt and nickel metal salt; wherein the molar ratio of cobalt metal salt to nickel metal salt in the mixed aqueous solution is (4-1):1; Step 2: Obtain the iron trisulfide phosphide suspension and place it into the mixed aqueous solution obtained in Step 1, stir until the mixture is uniform, and obtain a mixed solution; wherein, in the iron trisulfide phosphide suspension, the suspended matter is FePS3 nanosheets and the solvent is deionized water; Step 3: Under stirring conditions, ammonia water is added dropwise to the mixed solution obtained in step 2. After the addition is complete, stirring conditions are maintained and the reaction is allowed to proceed for a preset time. After the reaction is completed, the precipitate is obtained by centrifugation and washed repeatedly with deionized water and ethanol, and then dried to obtain a heterostructure of bimetallic hydroxide and iron trisulfide phosphide.

3. The method for preparing an anode oxygen evolution reaction catalyst according to claim 2, characterized in that, In step 1, the cobalt metal salt is cobalt sulfate, cobalt chloride, or cobalt nitrate; the nickel metal salt is nickel sulfate, nickel chloride, or nickel nitrate.

4. The method for preparing an anode oxygen evolution reaction catalyst according to claim 2, characterized in that, In step 3, the step of maintaining stirring conditions and reacting for a preset time, the stirring conditions are 500 rpm to 2000 rpm, and the preset time is 0.5 min to 15 min.

5. An anode oxygen evolution reaction catalyst prepared by any one of claims 1 to 4.

6. The application of the anodic oxygen evolution reaction catalyst according to claim 5, characterized in that, It is used as a catalyst for the oxygen evolution reaction at the anode in the water electrolysis process.

7. The application of the anodic oxygen evolution reaction catalyst according to claim 6, characterized in that, In preparing the anodic oxygen evolution reaction catalyst, the bimetallic compound in the bimetallic hydroxide and iron trisulfide phosphide heterostructure is cobalt and nickel; At 10mA cm -2 At a current density of [value missing], the overpotential and Tafel slope of the anolyte oxygen evolution reaction catalyst can reach 256 mV and 75 mV, respectively. -1 .

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