Preparation method and application of nickel-doped graded nano array electro-catalytic material

Abstract

The invention discloses a preparation method and application of a nickel-doped graded nano array electro-catalysis material, and relates to the technical field of nano material preparation, the preparation method comprises the following steps: preparing a solution by taking foamy copper as a substrate material and sodium hydroxide and ammonium persulfate as raw materials; a copper hydroxide nanobelt array precursor is synthesized on a foamy copper substrate in an in-situ growth mode through chemical oxidation treatment, then the precursor is converted into a nickel-doped cuprous sulfide nanorod array through hydro-thermal treatment, uniform nanosheets are formed on nanorods through the electro-deposition process, and the nickel-doped graded nanorod array electro-catalysis material can be obtained. By optimizing the synthesis method and adjusting the doping proportion, the obtained graded nano array shows relatively low overpotential and excellent stability in an electro-catalytic reaction, and the problems of low catalytic efficiency, poor durability and the like and insufficient stability of an existing catalyst are solved.

Description

Technical Field

[0001] The invention relates to the technical field of nano material preparation, and in particular to a preparation method and application of a nickel-doped hierarchical nano array electrocatalytic material. Background Art

[0002] In the context of the current energy crisis and increasingly serious environmental pollution, the development of efficient and renewable catalytic materials to promote the production and conversion of clean energy has become an important direction in the field of scientific research. Electrocatalysis plays an important role in energy conversion and storage, especially in hydrogen production reactions. So far, noble metals and their oxides (Pt / C and RuO2) are efficient HER and OER catalysts, but their high cost, low reserves and poor electrochemical stability are inevitable obstacles to large-scale application. Therefore, the development of new efficient and stable electrocatalytic materials has become a research hotspot.

[0003] Materials such as sulfides and hydroxides have attracted extensive attention in electrocatalytic applications due to their good electrochemical activity and stability. In particular, cuprous sulfide (Cu2S) is a promising electrocatalytic material that can exhibit excellent performance in a variety of electrocatalytic reactions due to its unique electronic structure and conductivity. However, pure cuprous sulfide still has certain limitations in terms of catalytic performance and stability, especially in terms of reactivity and durability.

[0004] In recent years, doping technology has been widely used to improve the electrocatalytic properties of materials. Studies have shown that the introduction of metal elements such as nickel (Ni) can effectively improve the catalytic activity of cuprous sulfide while enhancing its conductivity. In addition, cobalt hydroxide (Co(OH)2) has also attracted attention for its good electrocatalytic properties, and its combination with cuprous sulfide is expected to further improve the performance of the catalytic reaction. At the same time, self-supporting nanoarray electrocatalysts have also attracted widespread attention. First, the vertically arranged nanoarrays can provide a large electrochemically active area, allowing the electrolyte to effectively enter the active sites and accelerate the diffusion of electrolytes and gases; on the other hand, the in situ growth of the nanoarrays on the conductive substrate enables rapid charge transfer between the current collector and the active sites, and prevents delamination of the active substances.

[0005] In order to achieve the above research goals, it is particularly important to develop a new method for preparing nickel-doped hierarchical nanoarray electrocatalytic materials. The hierarchical structure can provide a larger specific surface area and abundant reactive sites, thereby improving the electrocatalytic efficiency of the material. However, the prior art still lacks a systematic synthesis method to effectively prepare such composite materials and demonstrate their superior performance in electrocatalytic reactions.

[0006] Therefore, it is necessary to explore and develop a new preparation technology of nickel-doped hierarchical nanoarray electrocatalytic materials and evaluate their application potential in electrocatalysis, in order to provide new solutions for the development of clean energy. Summary of the invention

[0007] The purpose of the present invention is to provide a method for preparing a nickel-doped hierarchical nanoarray electrocatalytic material; by optimizing the synthesis method and adjusting the doping ratio, the obtained hierarchical nanoarray exhibits a lower overpotential and excellent stability in the electrocatalytic reaction, thereby solving the problems of low catalytic efficiency, poor durability and insufficient stability of existing catalysts.

[0008] In order to achieve the above technical effects, the present invention is implemented by the following technical scheme: a method for preparing a nickel-doped hierarchical nanoarray electrocatalytic material, characterized in that it comprises the following steps:

[0009] S1. Preparation of copper hydroxide nanobelt array: sodium hydroxide and ammonium persulfate are weighed in a mass ratio of sodium hydroxide: ammonium persulfate = 1:0.2-0.3, and then the sodium hydroxide and ammonium persulfate are mixed with 20 mL of deionized water, stirred evenly at room temperature, and then a foam copper substrate is added, and a chemical oxidation reaction is carried out at 25-35° C. for 30-60 min. After the reaction is completed, the product is collected and washed with deionized water, and vacuum dried at 40-60° C. to obtain a copper hydroxide nanobelt array precursor with a self-supporting foam copper substrate;

[0010] S2. Preparation of nickel-doped cuprous sulfide nanorod arrays: nickel nitrate and sodium sulfide are weighed in a mass ratio of nickel salt: sulfur source = 2-4:30-60, and the nickel salt and the sulfur source are dissolved in 50 mL of deionized water. After stirring evenly at room temperature, the copper hydroxide nanobelt array precursor on the self-supporting copper foam substrate obtained in S1 is added to carry out a hydrothermal reaction at 120-180° C. for 6-12 h. After the reaction is completed, the product is collected and washed with deionized water, and vacuum dried at 50-60° C. to obtain a nickel-doped cuprous sulfide nanorod array on the copper foam substrate;

[0011] S3. Preparation of nickel-doped hierarchical nanoarray electrocatalytic material: Take 5-6g of cobalt salt and dissolve it in 100-200mL of deionized water. After stirring evenly at room temperature, add nickel-doped cuprous sulfide nanorod array based on foam copper, and then carry out electrodeposition treatment in an electric treatment box with a voltage of -1 to -2V for 10 to 60min. After the treatment, collect the product and wash it with deionized water. After vacuum drying at 50 to 60°C, the nickel-doped hierarchical nanoarray catalytic material can be obtained.

[0012] Furthermore, in S1, the size of the added copper foam substrate is 2*3cm 2 .

[0013] Furthermore, the diameter of the nickel-doped cuprous sulfide nanorods is 300 nm.

[0014] Another object of the present invention is to provide an application of a nickel-doped hierarchical nanoarray electrocatalytic material, characterized in that the nickel-doped hierarchical nanoarray catalytic material is used as an electrocatalytic working electrode and is applied to electrodes for hydrogen evolution and oxygen evolution reactions in water electrolysis.

[0015] Furthermore, the nickel-doped hierarchical nanoarray catalytic material is used as a bifunctional electrocatalyst in water decomposition hydrogen and oxygen evolution electrodes at 100 mA cm -2 The overpotential of hydrogen evolution is ≤262mV and the overpotential of oxygen evolution is ≤430mV at the current density.

[0016] The beneficial effects of the present invention are:

[0017] The nickel-doped hierarchical nano-array electrocatalytic material obtained by the preparation method of the present invention has the characteristics of uniform nano-size distribution, high specific surface area and high conductivity, and can be in-situ grown on a foam copper substrate to form a self-supporting hierarchical nano-array structure and directly used as an electrocatalyst electrode;

[0018] The present invention introduces metallic nickel into cuprous sulfide through an element doping strategy, which can adjust the electronic structure of the original cuprous sulfide, optimize the adsorption / desorption energy of the intermediate on the catalyst surface, and improve the electronic conductivity and catalytic efficiency of the material; the nickel-doped hierarchical nanoarray electrocatalytic material structure prepared by the present invention increases the specific surface area of ​​the material, increases more reaction sites, accelerates the rate of the electrochemical reaction, and enhances its stability in the electrocatalytic reaction;

[0019] The nickel-doped hierarchical nanoarray electrocatalytic material prepared by the present invention has high electrocatalytic activity and stability in both hydrogen evolution reaction and oxygen evolution reaction, and realizes the preparation of a bifunctional water decomposition electrocatalyst electrode;

[0020] The catalyst prepared by the present invention has a controllable structure and a simple preparation method, is suitable for large-scale production, can reduce production costs, and at the same time ensures the superiority of material performance, thus laying a foundation for the commercial application of electrocatalytic materials. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the accompanying drawings required for describing the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other accompanying drawings can be obtained based on these accompanying drawings without paying creative work.

[0022] Figure 1 The test results of hydrogen evolution and oxygen evolution performance of the nickel-doped hierarchical nanoarray electrocatalytic material sample prepared in Example 3 of the present invention;

[0023] Figure 2 The XRD spectrum of the nickel-doped hierarchical nanoarray electrocatalytic material prepared in Example 4 of the present invention;

[0024] Figure 3 This is a SEM image of the nickel-doped hierarchical nanoarray electrocatalytic material prepared in Example 4 of the present invention;

[0025] Figure 4 TEM image of the nickel-doped hierarchical nanoarray electrocatalytic material prepared in Example 4 of the present invention;

[0026] Figure 5 The test results of hydrogen evolution and oxygen evolution performance of the nickel-doped hierarchical nanoarray electrocatalytic material sample prepared in Example 4 of the present invention;

[0027] Figure 6 These are the test results of hydrogen evolution and oxygen evolution performance of the nickel-doped hierarchical nanoarray electrocatalytic material sample prepared in Example 5 of the present invention. DETAILED DESCRIPTION

[0028] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0029] Example 1

[0030] This embodiment provides a method for preparing a nickel-doped hierarchical nanoarray electrocatalytic material, which is implemented according to the following steps:

[0031] 1. Preparation of copper hydroxide nanoribbon arrays:

[0032] Weigh 2g of sodium hydroxide and 0.456g of ammonium persulfate respectively and dissolve them in 20mL of deionized water. Stir them evenly at room temperature to form a transparent solution. 2 The copper foam was placed in the solution to react for 30 minutes. After the reaction was completed, the surface of the copper foam substrate was repeatedly rinsed with deionized water, and a copper hydroxide nanobelt array precursor with a self-supporting copper foam substrate was obtained after vacuum drying.

[0033] Step 2: Preparation of nickel-doped cuprous sulfide nanorod arrays:

[0034] 0.03g nickel nitrate and 0.5g sodium sulfide were weighed and dissolved in 50mL deionized water, stirred evenly at room temperature, and then transferred to a high-pressure reactor, and the copper hydroxide nanobelt array precursor was placed in the solution of the reactor for hydrothermal treatment at 120°C for 6h. After cooling to room temperature, the surface of the foam copper substrate was repeatedly rinsed with deionized water, and the nickel-doped cuprous sulfide nanorod array based on the foam copper was obtained after vacuum drying.

[0035] Step 3: Preparation of nickel-doped hierarchical nanoarray electrocatalytic materials:

[0036] 5.82 g of cobalt nitrate was weighed and dissolved in 200 mL of deionized water. The solution was stirred evenly at room temperature to form a transparent solution. The nickel-doped cuprous sulfide nanorod array was placed in the solution. The electrodeposition reaction was carried out using an electrochemical workstation. The voltage was set to -1 V and the time was set to 400 s. After that, it was vacuum dried to obtain a nickel-doped hierarchical nanoarray electrocatalytic material based on foam copper, which can be directly used as an electrocatalytic working electrode.

[0037] Example 2

[0038] This embodiment provides a method for preparing a nickel-doped hierarchical nanoarray electrocatalytic material, which is implemented according to the following steps:

[0039] 1. Preparation of copper hydroxide nanoribbon arrays:

[0040] Weigh 2g of sodium hydroxide and 0.456g of ammonium persulfate respectively and dissolve them in 20mL of deionized water. Stir them evenly at room temperature to form a transparent solution. 2 The copper foam was placed in the solution to react for 60 minutes. After the reaction was completed, the surface of the copper foam substrate was repeatedly rinsed with deionized water, and a copper hydroxide nanobelt array precursor with a self-supporting copper foam substrate was obtained after vacuum drying.

[0041] Step 2: Preparation of nickel-doped cuprous sulfide nanorod arrays:

[0042] Weigh 0.03g nickel nitrate and 0.5g sodium sulfide respectively and dissolve them in 50mL deionized water. Stir them evenly at room temperature and transfer them to a high-pressure reactor. Place the copper hydroxide nanobelt array precursor in the reactor solution for hydrothermal treatment at 140°C for 6h. After cooling to room temperature, rinse the surface of the copper foam substrate repeatedly with deionized water, and vacuum dry to obtain nickel-doped cuprous sulfide nanorod arrays based on copper foam.

[0043] Step 3: Preparation of nickel-doped hierarchical nanoarray electrocatalytic materials:

[0044] 5.82 g of cobalt nitrate was weighed and dissolved in 200 mL of deionized water. The solution was stirred evenly at room temperature to form a transparent solution. The nickel-doped cuprous sulfide nanorod array was placed in the solution. The electrodeposition reaction was carried out using an electrochemical workstation. The voltage was set to -1 V and the time was set to 400 s. After that, it was vacuum dried to obtain a nickel-doped hierarchical nanoarray electrocatalytic material based on foam copper, which can be directly used as an electrocatalytic working electrode.

[0045] Example 3

[0046] This embodiment provides a method for preparing a nickel-doped hierarchical nanoarray electrocatalytic material, which is implemented according to the following steps:

[0047] 1. Preparation of copper hydroxide nanoribbon arrays:

[0048] Weigh 2g of sodium hydroxide and 0.456g of ammonium persulfate respectively and dissolve them in 20mL of deionized water. Stir them evenly at room temperature to form a transparent solution. 2 The copper foam was placed in the solution to react for 60 minutes. After the reaction was completed, the surface of the copper foam substrate was repeatedly rinsed with deionized water, and a copper hydroxide nanobelt array precursor with a self-supporting copper foam substrate was obtained after vacuum drying.

[0049] Step 2: Preparation of nickel-doped cuprous sulfide nanorod arrays:

[0050] Weigh 0.03g nickel nitrate and 0.5g sodium sulfide respectively and dissolve them in 50mL deionized water. Stir them evenly at room temperature and transfer them to a high-pressure reactor. Place the copper hydroxide nanobelt array precursor in the reactor solution for hydrothermal treatment at 160°C for 6h. After cooling to room temperature, rinse the surface of the copper foam substrate repeatedly with deionized water, and vacuum dry to obtain nickel-doped cuprous sulfide nanorod arrays based on copper foam.

[0051] Step 3: Preparation of nickel-doped hierarchical nanoarray electrocatalytic materials:

[0052] 5.82 g of cobalt nitrate was weighed and dissolved in 200 mL of deionized water. The solution was stirred evenly at room temperature to form a transparent solution. The nickel-doped cuprous sulfide nanorod array was placed in the solution. The electrodeposition reaction was carried out using an electrochemical workstation. The voltage was set to -1 V and the time was set to 400 s. After that, it was vacuum dried to obtain a nickel-doped hierarchical nanoarray electrocatalytic material based on foam copper, which can be directly used as an electrocatalytic working electrode.

[0053] The electrochemical performance of the nickel-doped hierarchical nanoarray electrocatalytic material prepared in this example was tested. A three-electrode system was used, with a carbon rod electrode as the counter electrode, silver chloride as the reference electrode, the prepared self-supporting nickel-doped hierarchical nanoarray electrocatalytic material catalyst as the working electrode, and 1 mol / L potassium hydroxide solution as the electrolyte. Electrocatalytic hydrogen and oxygen evolution tests were performed using an electrochemical workstation. The polarization curves obtained are shown in FIG. Figure 1 As shown, the performance is excellent; 100mA cm -2 The overpotential for hydrogen evolution is 275 mV and the overpotential for oxygen evolution is 515 mV at this current density.

[0054] Example 4

[0055] This embodiment provides a method for preparing a nickel-doped hierarchical nanoarray electrocatalytic material, which is implemented according to the following steps:

[0056] 1. Preparation of copper hydroxide nanoribbon arrays:

[0057] Weigh 2g of sodium hydroxide and 0.456g of ammonium persulfate respectively and dissolve them in 20mL of deionized water. Stir them evenly at room temperature to form a transparent solution. 2 The copper foam was placed in the solution to react for 60 minutes. After the reaction was completed, the surface of the copper foam substrate was repeatedly rinsed with deionized water, and a copper hydroxide nanobelt array precursor with a self-supporting copper foam substrate was obtained after vacuum drying.

[0058] Step 2: Preparation of nickel-doped cuprous sulfide nanorod arrays:

[0059] Weigh 0.03g nickel nitrate and 0.5g sodium sulfide respectively and dissolve them in 50mL deionized water. Stir them evenly at room temperature and transfer them to a high-pressure reactor. Place the copper hydroxide nanobelt array precursor in the reactor solution for hydrothermal treatment at 160°C for 6h. After cooling to room temperature, rinse the surface of the copper foam substrate repeatedly with deionized water, and vacuum dry to obtain nickel-doped cuprous sulfide nanorod arrays based on copper foam.

[0060] Step 3: Preparation of nickel-doped hierarchical nanoarray electrocatalytic materials:

[0061] Weigh 5.82g of cobalt nitrate and dissolve it in 200mL of deionized water. Stir it evenly at room temperature to form a transparent solution. Place the nickel-doped cuprous sulfide nanorod array in the solution. Use an electrochemical workstation to carry out electrodeposition reaction. Set the voltage to -1V and the time to 600s. Then vacuum dry it to obtain a nickel-doped hierarchical nanoarray electrocatalytic material based on foam copper, which can be directly used as an electrocatalytic working electrode.

[0062] The nickel-doped hierarchical nanoarray electrocatalytic material prepared in this embodiment was characterized by X-ray diffraction (XRD). Figure 2 As shown, the positions of the XRD peaks of the prepared samples conform to the standard peak types of cuprous sulfide and cobalt hydroxide.

[0063] The nickel-doped hierarchical nanoarray electrocatalytic material prepared in this example was characterized by scanning electron microscopy (SEM) and transmission electron microscopy (TEM). Figure 3 ,4 shows, it can be seen that the prepared material presents a hierarchical nanoarray morphology structure, the nanorods are composed of nickel-doped cuprous sulfide with an average diameter of 300nm, and the nanosheets are composed of cobalt hydroxide.

[0064] The electrochemical performance of the nickel-doped hierarchical nanoarray electrocatalytic material prepared in this example was tested. A three-electrode system was used, with a carbon rod electrode as the counter electrode, silver chloride as the reference electrode, the prepared self-supporting nickel-doped hierarchical nanoarray electrocatalytic material catalyst as the working electrode, and 1 mol / L potassium hydroxide solution as the electrolyte. Electrocatalytic hydrogen and oxygen evolution tests were performed using an electrochemical workstation. The polarization curves obtained are shown in FIG. Figure 5 As shown, the performance is excellent; 100mA cm -2 The overpotential for hydrogen evolution is 262 mV and the overpotential for oxygen evolution is 430 mV at this current density.

[0065] Example 5

[0066] This embodiment provides a method for preparing a nickel-doped hierarchical nanoarray electrocatalytic material, which is implemented according to the following steps:

[0067] 1. Preparation of copper hydroxide nanoribbon arrays:

[0068] Weigh 2g of sodium hydroxide and 0.456g of ammonium persulfate respectively and dissolve them in 20mL of deionized water. Stir them evenly at room temperature to form a transparent solution. 2 The copper foam was placed in the solution to react for 60 minutes. After the reaction was completed, the surface of the copper foam substrate was repeatedly rinsed with deionized water, and a copper hydroxide nanobelt array precursor with a self-supporting copper foam substrate was obtained after vacuum drying.

[0069] Step 2: Preparation of nickel-doped cuprous sulfide nanorod arrays:

[0070] Weigh 0.03g nickel nitrate and 0.5g sodium sulfide respectively and dissolve them in 50mL deionized water. Stir them evenly at room temperature and transfer them to a high-pressure reactor. Place the copper hydroxide nanobelt array precursor in the reactor solution for hydrothermal treatment at 160°C for 6h. After cooling to room temperature, rinse the surface of the copper foam substrate repeatedly with deionized water, and vacuum dry to obtain nickel-doped cuprous sulfide nanorod arrays based on copper foam.

[0071] Step 3: Preparation of nickel-doped hierarchical nanoarray electrocatalytic materials:

[0072] Weigh 5.82g of cobalt nitrate and dissolve it in 200mL of deionized water. Stir it evenly at room temperature to form a transparent solution. Place the nickel-doped cuprous sulfide nanorod array in the solution. Use an electrochemical workstation to carry out an electrodeposition reaction. Set the voltage to -1V and the time to 800s. Then vacuum dry it to obtain a nickel-doped hierarchical nanoarray electrocatalytic material based on foam copper, which can be directly used as an electrocatalytic working electrode.

[0073] The electrochemical performance of the nickel-doped hierarchical nanoarray electrocatalytic material prepared in this example was tested. A three-electrode system was used, with a carbon rod electrode as the counter electrode, silver chloride as the reference electrode, the prepared self-supporting nickel-doped hierarchical nanoarray electrocatalytic material catalyst as the working electrode, and 1 mol / L potassium hydroxide solution as the electrolyte. Electrocatalytic hydrogen and oxygen evolution tests were performed using an electrochemical workstation. The polarization curves obtained are shown in FIG. Figure 6 As shown, the performance is excellent; 100mA cm -2 The overpotential for hydrogen evolution is 308 mV and the overpotential for oxygen evolution is 520 mV at this current density.

[0074] The present invention uses copper foam as a base material, sodium hydroxide and ammonium persulfate as raw materials to form a solution, and in-situ grows and synthesizes a copper hydroxide nanobelt array precursor on the copper foam substrate through chemical oxidation treatment, and then converts the precursor into a nickel-doped cuprous sulfide nanorod array through hydrothermal treatment, and further forms uniform nanosheets on the nanorods through an electrodeposition process, and obtains a nickel-doped hierarchical nanoarray electrocatalytic material. In the present invention, due to the effect of the copper foam substrate, a uniformly distributed nanoarray structure is grown in situ, so that it has a large specific surface area. In the present invention, a large number of sulfur vacancies are also generated in the generation process of the nickel-doped cuprous sulfide nanorod array, the electronic structure is optimized, and more active sites are provided; by uniformly growing cobalt hydroxide nanosheets on the surface of the cuprous sulfide nanorods, a nickel-doped hierarchical nanoarray electrocatalytic material structure is constructed, which is conducive to the full diffusion and penetration of the electrolyte, thereby accelerating the catalytic reaction rate. The method realizes the synergistic effect of nickel-doped cuprous sulfide and cobalt hydroxide by controlling the reaction conditions, and forms a hierarchical nanostructure with excellent electrocatalytic performance. The nickel-doped hierarchical nanoarray electrocatalytic material of the present invention has good application prospects in the field of electrocatalysis, can effectively improve reaction efficiency, and provide a new solution for the development of new energy technologies.

[0075] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention rather than to limit it. Although the present invention has been described in detail with reference to the above embodiments, ordinary technicians in the relevant field should understand that the specific implementation methods of the present invention can still be modified or replaced by equivalents. Any modification or equivalent replacement that does not depart from the spirit and scope of the present invention should be covered within the scope of protection of the claims of the present invention.

Claims

1. A method for preparing a nickel-doped hierarchical nanoarray electrocatalytic material, characterized in that: The following steps are involved: S1. Preparation of copper hydroxide nanobelt array: sodium hydroxide and ammonium persulfate are weighed in a mass ratio of sodium hydroxide: ammonium persulfate = 1:0.2-0.3, and then the sodium hydroxide and ammonium persulfate are mixed with 20 mL of deionized water, stirred evenly at room temperature, and then a foam copper substrate is added, and a chemical oxidation reaction is carried out at 25-35° C. for 30-60 min. After the reaction is completed, the product is collected and washed with deionized water, and vacuum dried at 40-60° C. to obtain a copper hydroxide nanobelt array precursor with a self-supporting foam copper substrate; S2. Preparation of nickel-doped cuprous sulfide nanorod arrays: nickel nitrate and sodium sulfide are weighed in a mass ratio of nickel salt: sulfur source = 2-4:30-60, and the nickel salt and the sulfur source are dissolved in 50 mL of deionized water. After stirring evenly at room temperature, the copper hydroxide nanobelt array precursor on the self-supporting copper foam substrate obtained in S1 is added to carry out a hydrothermal reaction at 120-180° C. for 6-12 h. After the reaction is completed, the product is collected and washed with deionized water, and vacuum dried at 50-60° C. to obtain a nickel-doped cuprous sulfide nanorod array on the copper foam substrate; S3. Preparation of nickel-doped hierarchical nanoarray electrocatalytic material: Take 5-6g of cobalt salt and dissolve it in 100-200mL of deionized water. After stirring evenly at room temperature, add nickel-doped cuprous sulfide nanorod array based on foam copper, and then carry out electrodeposition treatment in an electric treatment box with a voltage of -1 to -2V for 10 to 60min. After the treatment, collect the product and wash it with deionized water. After vacuum drying at 50 to 60°C, the nickel-doped hierarchical nanoarray catalytic material can be obtained.

2. The method for preparing a nickel-doped hierarchical nanoarray electrocatalytic material according to claim 1, characterized in that: In S1, the size of the added copper foam substrate is 2*3cm 2 .

3. The method for preparing a nickel-doped hierarchical nanoarray electrocatalytic material according to claim 1, characterized in that: The diameter of the nickel-doped cuprous sulfide nanorods is 300 nm.

4. An application of a nickel-doped hierarchical nanoarray electrocatalytic material, characterized in that: The nickel-doped hierarchical nano-array catalytic material is used as an electrocatalytic working electrode and is applied to electrodes for hydrogen evolution and oxygen evolution reactions in water electrolysis.

5. The use of a nickel-doped hierarchical nanoarray electrocatalytic material according to any one of claim 4, characterized in that: The nickel-doped hierarchical nanoarray catalytic material is used as an electrocatalytic working electrode in water decomposition of hydrogen and oxygen evolution electrodes at 100 mA cm -2 The overpotential of hydrogen evolution is ≤262mV and the overpotential of oxygen evolution is ≤430mV at the current density.

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