Method for preparing electrode material through pulse electrodeposition and application of method in oxygen evolution reaction

Abstract

The invention relates to a preparation technology of an electrochemical catalytic material, and aims to provide a method for preparing an electrode material through pulse electrodeposition and application of the electrode material in an oxygen evolution reaction. The method comprises the following steps: constructing a dual-electrode electrolysis system, and co-depositing transition metal ions and selenium ions on a working electrode by adopting a pulse electrodeposition method to form a catalyst layer containing transition metal and selenide; then the working electrode is used for building an electrochemical system, electrochemical activation treatment is conducted on the working electrode through cyclic voltammetry, a selenium phase is induced to fall off, porous metal oxide is formed by reconstructing the surface of a catalyst layer, and the electrode material for the water electrolysis oxygen evolution reaction is obtained. The selenium phase is induced to fall off through electrochemical activation to form a porous metal oxide structure, the specific surface area is remarkably increased, rich oxygen vacancies are formed, the electronic structure is optimized, more active sites are exposed, and the catalytic activity is improved; the method is easy to operate, high in parameter controllability, free of high-temperature and high-pressure equipment and suitable for large-scale production.

Description

Technical Field

[0001] The present invention relates to the technical field of electrochemical catalytic material preparation, and in particular to a method for preparing an electrode material by pulse electrodeposition, and application of the electrode material in an oxygen evolution reaction. Background Art

[0002] Hydrogen production by water electrolysis has attracted widespread attention as an efficient and environmentally friendly method for hydrogen production. The oxygen evolution reaction (OER) is an important half-reaction in the process of hydrogen production by water electrolysis. Precious metal-based catalysts (such as IrO2 and RuO2) are commonly used catalysts for the OER reaction, but their high cost and scarcity limit their large-scale application. Therefore, the development of low-cost, efficient and stable non-precious metal-based OER catalysts is of great significance.

[0003] Current research results show that the OER reaction is still limited by slow kinetics and requires efficient electrocatalysts to reduce overpotential and improve reaction efficiency. The OER reaction mainly includes two reaction mechanisms: adsorbate evolution (AEM) and lattice oxygen mediation (LOM): i). The AEM mechanism involves the adsorption and desorption process of intermediates (OH ads →O ads →OOH ads →O 2ads ), in which the adsorption energies of the OER intermediates (*OH and *OOH) on the metal active sites show a linear relationship (ΔG OOH =ΔG OH +3.2±0.2eV), the theoretical overpotential is about 370mV. ii). The LOM mechanism relies on the mediation of lattice oxygen, and the lattice oxygen atoms of the catalyst directly participate in OO coupling, which is conducive to breaking the linear relationship and reducing the theoretical overpotential. The LOM mechanism is more likely to occur in amorphous metal oxides with a large number of oxygen vacancies and inclusion crystals with high metal-oxygen ligand covalency. This mechanism relies on the mediation of lattice oxygen. Oxygen vacancy defects (Oxygen vacancy, OV) are widely present in metal oxides and affect the local geometric structure and electronic structure of the material, resulting in unsaturated coordination sites, thereby forming a large number of catalytic reaction active sites. OV can also promote the adsorption and conversion of intermediates, effectively regulate the electronic structure, inhibit competitive reactions, and thus improve the overall catalytic performance.

[0004] Ni in nickel-cobalt compounds 2+ / Ni 3+ and Co 2+ / Co 3+ The two redox pairs can effectively promote the adsorption and conversion of reaction intermediates, reduce the reaction energy barrier, and thus enhance the OER activity. At the same time, nickel-cobalt compounds are highly controllable and can be easily doped with other elements to enhance catalytic performance. Selenium ions (Se 2-) has a lower oxidation potential (0.74 V vs. SHE) than oxygen (O 2- The oxidation potential of Se is 0.40 V vs. SHE). During the electrochemical activation process, Se 2- More easily oxidized to Se 4+ And dissolve away from the electrode surface, thus providing active sites for the formation of oxygen vacancies. And selenide has the ability to reconstruct in situ, and the shedding of selenium phase substances drives the reconstruction of the surface of metal oxides (such as NiO, Co3O4), exposing more active sites. Therefore, the use of nickel, cobalt and selenium metals to prepare electrode materials has become a new research direction, but the existing preparation schemes are usually prepared by hydrothermal, coprecipitation, high-temperature pyrolysis, constant current electrodeposition and other methods, which have problems such as harsh preparation conditions, high cost and poor material stability.

[0005] Therefore, the present invention proposes a new technical solution to solve the above problems. Summary of the Invention

[0006] The technical problem to be solved by the present invention is to overcome the deficiencies in the prior art and provide a method for preparing an electrode material by pulse electrodeposition and its application in an oxygen evolution reaction.

[0007] To solve the technical problem, the solution of the present invention is:

[0008] A method for preparing an electrode material by pulse electrodeposition is provided, comprising:

[0009] (1) dissolving a transition metal salt and a selenium source in deionized water and stirring uniformly to prepare a precursor solution;

[0010] (2) Using nickel foam as the working electrode and platinum sheet as the counter electrode, the precursor solution is added to the electrolytic cell to build a two-electrode electrolysis system; transition metal ions and selenium ions are co-deposited on the working electrode by pulse electrodeposition, forming a catalyst layer containing transition metal and selenide on the surface of the working electrode;

[0011] (3) After cleaning the working electrode, it is immersed in alkaline solution together with the graphite counter electrode and the Hg / HgO reference electrode to jointly build an electrochemical system; the working electrode is electrochemically activated by cyclic voltammetry to induce the selenium phase in the catalyst layer of the working electrode to fall off; the surface of the catalyst layer is reconstructed to form a porous metal oxide, thereby obtaining an electrode material for the electrolysis of water and oxygen evolution reaction.

[0012] As a preferred embodiment of the present invention, the transition metal is one or more of nickel, cobalt, iron or copper, and the transition metal salt is nitrate, chloride or acetate.

[0013] As a preferred embodiment of the present invention, the selenium source is selenium dioxide.

[0014] As a preferred embodiment of the present invention, in the precursor solution, the molar ratio of each transition metal ion to selenium ion is 1:1.

[0015] As a preferred embodiment of the present invention, in step (2), before using the nickel foam, it is ultrasonically cleaned with acetone, ethanol and deionized water for 10 to 30 minutes respectively, and then dried at 60° C. for 30 to 60 minutes.

[0016] As a preferred embodiment of the present invention, the alkali solution is a KOH solution with a concentration of 1M.

[0017] As a preferred embodiment of the present invention, when pulse electrodeposition is used for co-deposition, the control parameters are: pulse current density 30mA / cm 2 , pulse width 2s, pulse interval 0.4~10s, total deposition time 360~1800s.

[0018] As a preferred embodiment of the present invention, when the electrochemical activation treatment is performed by cyclic voltammetry, the control parameters are: scan rate 50 mV / s, scan range 0.3-1 V vs. Hg / HgO, and cycle number 50 times.

[0019] The present invention further provides the use of the electrode material prepared by the above method in the oxygen evolution reaction of water electrolysis.

[0020] Brief description of the invention principle:

[0021] The innovative design of the present invention is to propose an in-situ self-reconstruction method for preparing transition metal selenide electrode materials; by utilizing the shedding of selenide during the activation process to provide a larger specific surface area, more active sites are exposed, and the catalytic performance and stability are significantly improved. The present invention uses selenide to construct oxygen vacancies, and through pulse electrodeposition technology combined with electrochemical activation treatment, while the selenium phase is shedding, it induces the formation of abundant oxygen vacancies in the surface lattice of metal oxides (such as NiO, Co3O4). The presence of oxygen vacancies reduces the oxygen adsorption energy barrier on the surface of the material and optimizes the electron transfer path, thereby significantly reducing the OER overpotential and improving stability. It solves the problem of insufficient controllability of oxygen vacancies in traditional methods and provides a dual optimization mechanism for improving catalytic performance.

[0022] This method leverages the mild conditions and highly controllable parameters of pulse electrodeposition technology. By adjusting pulse parameters (such as pulse width, interval time, and current density), the material's microstructure and surface chemistry can be precisely controlled, achieving targeted regulation of oxygen vacancy density and distribution. Compared with traditional preparation methods (such as hydrothermal and constant current / piezoelectric deposition), this method offers better control over reaction conditions, more precise regulation of the distribution of defects and highly active sites, and reduces production costs.

[0023] Compared with the prior art, the present invention has the following beneficial effects:

[0024] 1. The present invention can effectively control oxygen vacancies: by inducing the formation of abundant oxygen vacancies on the surface of metal oxides during electrochemical activation, the electronic structure is optimized and abundant active sites are provided, thereby accelerating the OER reaction kinetics. XPS analysis confirms that the combination energy of nickel phase and cobalt is reduced after electrochemical activation treatment ( Figure 3-4 ), selenium phase material disappears ( Figure 5 ), and the oxygen content is reduced ( Figure 6 ), indicating that a large number of oxygen vacancies were formed after electrochemical activation, which is directly related to the improvement of catalytic performance.

[0025] 2. The present invention can improve the performance of the oxygen evolution reaction: through pulse electrodeposition combined with electrochemical activation treatment, in-situ self-reconstruction is achieved, thereby improving electrode stability. The selenium phase is shed to form a porous metal oxide structure (such as NiO and Co3O4), which significantly increases the specific surface area, exposes more active sites, and improves catalytic activity, which is superior to traditional transition metal selenides and unactivated comparative materials. At the same time, the catalyst achieves self-optimization during the OER process through dynamic shedding of the selenium phase and generation of oxygen vacancies, further extending its service life and meeting the long-term operation requirements of industrial electrolyzers.

[0026] 3. This invention reduces the use of precious metals and lowers production costs: By using non-precious metal raw materials (Ni, Co, Se), the cost of precious metal catalysts (such as IrO2 and RuO2) is reduced by over 80%. By adjusting the type of transition metal salt (such as nickel, cobalt, iron, copper) and the precursor ratio, composite catalysts with different compositions can be flexibly designed to meet diverse needs for hydrogen production from water electrolysis.

[0027] 4. The method of the present invention is simple to operate, has highly controllable parameters (such as pulse current density, width, and interval), does not require high-temperature and high-pressure equipment, and is suitable for large-scale production. The prepared electrode material is applied in electrolytic cells and exhibits excellent electrocatalytic oxygen evolution performance. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] Figure 1 (a) and (b) are scanning electron microscope (SEM) images of the catalyst layers prepared in comparative example 1 and example 1 of the present invention, respectively.

[0029] Figure 2 The X-ray diffraction patterns (XRD) of the catalysts prepared in Example 1 and Comparative Example 1 of the present invention are shown.

[0030] Figure 3 1 is the electron paramagnetic resonance (EPR) pattern of the catalysts prepared in Example 1 and Comparative Example 1.

[0031] Figure 41 is a Co 2p peak diagram of the X-ray photoelectron spectroscopy (XPS) of the catalysts prepared in Example 1 and Comparative Example 1.

[0032] Figure 5 It is the Ni 2p peak diagram of the X-ray photoelectron spectroscopy (XPS) of the catalysts prepared in Example 1 and Comparative Example 1.

[0033] Figure 6 It is the Se 3d peak diagram of the X-ray photoelectron spectroscopy (XPS) of the catalysts prepared in Example 1 and Comparative Example 1.

[0034] Figure 7 It is the O 1s peak diagram of the X-ray photoelectron spectroscopy (XPS) of the catalysts prepared in Example 1 and Comparative Example 1.

[0035] Figure 8 It is the full spectrum of X-ray photoelectron spectroscopy (XPS) of the catalysts prepared in Example 1 and Comparative Example 1.

[0036] Figure 9 Polarization curves of the catalysts prepared in Examples 1-3 of the present invention and Comparative Example 2 in 1 M KOH.

[0037] Figure 10 This is a graph showing the IT stability test of the catalyst prepared in Example 1 of the present invention in 1 M KOH for 24 hours. DETAILED DESCRIPTION

[0038] The present invention is described in detail below with reference to specific embodiments.

[0039] Part I. Examples and Comparative Examples

[0040] Example 1

[0041] Preparation of NiCoSe based on nickel foam (NF) x / NF electrode materials

[0042] The nickel foam was cut into 1 cm × 2 cm size, ultrasonically cleaned with acetone, ethanol and deionized water for 10 min respectively, dried at 60 ° C for 30 min and then used.

[0043] Dissolve NiCl3·6H2O, Co(NO)3·6H2O, and SeO2 in 50 mL of deionized water at a molar ratio of 1:1:1, stir evenly, and obtain a precursor solution. Pour the solution into an electrolytic cell. A two-electrode system was constructed using nickel foam as the working electrode and platinum sheet as the counter electrode for pulse electrodeposition. The pulse current density was controlled at 30 mA / cm 2 , pulse width 2s, pulse interval 2s, pulse 150 times (2s / time), total deposition time 600s.

[0044] Remove the working electrode, clean it, and then immerse it in a 1 M KOH solution as the working electrode, a graphite rod as the counter electrode, and Hg / HgO as the reference electrode to construct an electrochemical system. Activate the working electrode via cyclic voltammetry. Use a scan rate of 50 mV / s over a range of 0.3–1 V vs. Hg / HgO, and perform 50 cycles.

[0045] Take out the working electrode and clean it, which is NiCoSe x / NF electrode materials.

[0046] The electrode material can be directly used in the oxygen evolution reaction of water electrolysis, and the specific method of using it is to use it as an anode for oxygen evolution reaction (OER).

[0047] Example 2

[0048] The process was carried out in accordance with Example 1. The difference from Example 1 was that the pulse electrodeposition parameters were controlled as follows: pulse current density 30 mA / cm 2 , pulse width 2s, pulse interval 10s, total deposition time 1800s.

[0049] Example 3

[0050] The process was carried out in accordance with Example 1. The difference from Example 1 was that the pulse electrodeposition parameters were controlled as follows: pulse current density 30 mA / cm 2 , pulse width 2s, pulse interval 0.4s, total deposition time 360s.

[0051] Example 4

[0052] Preparation of NiFeSe based on nickel foam (NF) x / NF electrode materials

[0053] The nickel foam was cut into 1 cm × 2 cm size, ultrasonically cleaned with acetone, ethanol and deionized water for 20 min respectively, dried at 60 ° C for 40 min and then used.

[0054] Dissolve NiCl3·6H2O, Fe(NO3)3·9H2O, and SeO2 in 50 mL of deionized water at a molar ratio of 1:1:1, stir evenly, and obtain a precursor solution. Pour the solution into an electrolytic cell. A two-electrode system was constructed using nickel foam as the working electrode and platinum sheet as the counter electrode for pulse electrodeposition. The pulse current density was controlled at 30 mA / cm 2 , pulse width 2s, pulse interval 2s, pulse 300 times, total deposition time 600s.

[0055] Remove the working electrode, clean it, and then immerse it in a 1 M KOH solution as the working electrode, a graphite rod as the counter electrode, and Hg / HgO as the reference electrode to construct an electrochemical system. Activate the working electrode via cyclic voltammetry. Use a scan rate of 50 mV / s over a range of 0.3–1 V vs. Hg / HgO, and perform 50 cycles.

[0056] Take out the working electrode and clean it to obtain NiFeSe x / NF electrode materials.

[0057] The electrode material can be directly used in the oxygen evolution reaction of water electrolysis, and the specific method of using it is to use it as an anode for oxygen evolution reaction (OER).

[0058] Example 5

[0059] Preparation of NiCuSe based on nickel foam (NF) x / NF electrode materials

[0060] The nickel foam was cut into 1 cm × 2 cm size, ultrasonically cleaned with acetone, ethanol and deionized water for 30 min respectively, dried at 60 ° C for 60 min and then used.

[0061] Dissolve NiCl3·6H2O, Cu(CO2CH3)2·H2O, and SeO2 in 50 mL of deionized water at a molar ratio of 1:1:1, stir evenly, and obtain a precursor solution. Pour the solution into an electrolytic cell. A two-electrode system was constructed using nickel foam as the working electrode and platinum sheet as the counter electrode for pulse electrodeposition. The pulse current density was controlled at 30 mA / cm 2 , pulse width 2s, pulse interval 2s, pulse 300 times, total deposition time 600s.

[0062] Remove the working electrode, clean it, and then immerse it in a 1 M KOH solution as the working electrode, a graphite rod as the counter electrode, and Hg / HgO as the reference electrode to construct an electrochemical system. Activate the working electrode via cyclic voltammetry. Use a scan rate of 50 mV / s over a range of 0.3–1 V vs. Hg / HgO, and perform 50 cycles.

[0063] Take out the working electrode and clean it to obtain NiCuSe x / NF electrode materials.

[0064] The electrode material can be directly used in the oxygen evolution reaction of water electrolysis, and the specific method of using it is to use it as an anode for oxygen evolution reaction (OER).

[0065] Comparative Example 1

[0066] The same procedure as in Example 1 was followed, except that after the catalyst layer was formed on the nickel foam substrate by pulse electrodeposition, no electrochemical activation treatment was performed. The other steps and control parameters were the same as in Example 1. This comparative example 1 was used to confirm the effect of electrochemical activation treatment on the morphology and composition of the electrode material.

[0067] Comparative Example 2

[0068] The process was carried out in accordance with Example 1, except that constant current electrodeposition was performed with a current density of 30 mA / cm 2 , total deposition time 300s.

[0069] Comparative Example 3

[0070] Referring to patent CN115852425A, a nickel-cobalt based catalyst was prepared by hydrothermal method:

[0071] NiCl2·6H2O and CoCl2·6H2O were dissolved in deionized water, magnetically stirred until clear, and then urea was added and stirred continuously. The mixture was then transferred to a hydrothermal reactor and reacted at high temperature for 12 hours. The solid was collected by centrifugation. The obtained solid was washed with ultrapure water and ethanol in sequence, and then vacuum dried to obtain the product. The product was ground and immersed in a Na2S solution, centrifuged, and freeze-dried to obtain the catalyst of Comparative Example 3. After room temperature vulcanization, the surface of the material retained the morphology of the nanosheets of the nickel-cobalt hydrotalcite precursor.

[0072] Comparative Example 4

[0073] Referring to patent CN116479468A, the catalyst was prepared by constant current electrodeposition:

[0074] A nickel rod (anode) and a pretreated 316L stainless steel substrate (cathode) were connected to an electrochemical workstation. The substrates were polished, rinsed with dilute hydrochloric acid and deionized water, and air-dried. Constant current electrodeposition was performed under magnetic stirring and a vertical external magnetic field to obtain the catalyst of Comparative Example 4. This catalyst initially consisted of nickel-cobalt-phosphorus amorphous nanoclusters, whose surface reconstructed into an upright nanosheet structure during water electrolysis.

[0075] Part II Test Results and Analysis

[0076] 1. Effect of electrochemical activation treatment on the morphology and performance of the catalyst layer

[0077] Through scanning electron microscopy Figure 1 (a) It was observed that the surface morphology of the catalyst layer in the electrode material of Comparative Example 1 was relatively rough, accompanied by some micron-sized spherical particles, the particle distribution was uneven, and there was a large agglomeration phenomenon. Figure 1 (b) NiCoSe is the electrode material in Example 1 xFrom the scanning electron microscope photograph of the catalyst layer on the surface of the NF, it can be seen that the catalyst layer on the surface of the electrode material prepared by the present invention has a rich pore structure, which is conducive to exposing more specific surface area, thereby providing more active sites.

[0078] from Figure 2 The X-ray diffraction pattern (XPS) in the embodiment 1 shows that the electrode material has obvious cobalt phase and nickel phase, indicating that NiCoSe x The catalyst layer on the surface of the NF is a nickel-cobalt-selenide oxide composite. The electrode material in Comparative Example 1 exhibits five distinct diffraction peaks, corresponding to the standard card diffraction peaks of nickel selenide and cobalt selenide, indicating that the substrate in Comparative Example 1 has also successfully loaded nickel, cobalt, and selenium.

[0079] Based on the above scanning electron microscopy comparison, it can be seen that the surface pore structure of the electrode material that has not been electrochemically activated is not obvious and the surface active sites are few. After electrochemical activation, it presents a porous structure and increased porosity; and oxygen vacancies are usually enriched at the pore edges or grain boundaries, which is conducive to providing more active sites for OER. Based on the comparison of X-ray diffraction patterns, it can be seen that the diffraction peak of the selenium phase in Example 1 disappears, leaving only the diffraction peaks corresponding to the cobalt phase and the nickel phase, indicating that the electrochemical activation treatment of the working electrode by cyclic voltammetry has caused the selenium phase in the catalyst layer to fall off.

[0080] Figure 3 1 and 2 are EPR spectra of Example 1 and Comparative Example 1. The EPR spectrum of Example 1 shows a strong signal of g=2.003, which is because electrons are trapped at defect sites, confirming that a large number of oxygen vacancies are formed in Example 1 during the electrochemical activation process.

[0081] Figure 4-6 The XPS spectra of Ni, Co, and Si in Example 1 and Comparative Example 1 show that after electrochemical activation, the binding energy between the nickel and cobalt phases decreases, indicating reduction. Furthermore, the diffraction peaks of the selenium phase disappear after electrochemical oxidation, indicating that it has fallen off the electrode surface.

[0082] Figure 7 The XPS graphs of O1s of Example 1 and Comparative Example 1 show that the lattice oxygen content of Example 1 decreases and the vacancy oxygen content increases.

[0083] Figure 8 The full XPS spectra of Example 1 and Comparative Example 1 show that the O1s content decreases and the Se3d peak disappears during the electrochemical oxidation treatment, further illustrating the above conclusion.

[0084] comprehensive Figure 2-6XPS spectrum and the above analysis: On the one hand, the present invention has the preferential removal of Se, which provides space for the formation of oxygen vacancies; on the other hand, due to the rapid structural reorganization and charge compensation mechanism, due to the shedding of selenium phase material, Se 2- After dissolution causes the oxidation state of metal Ni / Co to increase, charge balance is needed to maintain electrical neutrality. Oxygen vacancies can serve as charge compensation defects to stabilize the high-valent metal state. Due to reaction kinetic limitations, oxygen vacancies are left to maintain charge balance, resulting in a decrease in the binding energy of nickel and cobalt phases.

[0085] Based on the above analysis, it is shown that after electrochemical activation treatment, the selenium phase material in the electrode material of the present invention falls off, the oxygen vacancies increase, and a richer pore structure is formed, which is conducive to exposing more active sites and providing a larger specific surface area, which has an important impact on improving the performance of the material.

[0086] 2. Practical application effect of the electrode material of the present invention in OER reaction

[0087] The electrode material prepared by the present invention can be directly used as an anode for oxygen evolution reaction in water electrolysis.

[0088] To investigate the practical application of the catalyst layer on the electrode material surface in the OER reaction, the electrode materials prepared in Examples 1-5 of the present invention and Comparative Examples 2-4 were used to construct a three-electrode system connected to a CHI1140E electrochemical workstation to evaluate the OER electrochemical performance of the materials. The electrode material of the present invention (1 cm × 2 cm), a graphite rod, and Hg / HgO were used as the working electrode, counter electrode, and reference electrode, respectively.

[0089] The catalytic performance of the electrode materials was tested by the linear voltammetry (LSV) method.

[0090] The LSV test conditions were: at room temperature, in 1 M KOH solution, at a scan rate of 5 mV / s. All LSV reactions were corrected by iR compensation (80%).

[0091] The measured potential of OER was converted to reversible hydrogen electrode (RHE) according to the following equation:

[0092] E(vs.RHE)=E(vs.Hg / HgO)+0.098+0.059×pH

[0093] Examples 1-5 at 1000 mA / cm 2 The specific data of voltage and overpotential under the condition are shown in Table 1.

[0094] Table 1:

[0095] Group Voltage (V) Overpotential (mV) Example 1 1.70 470 Example 2 1.777 547 Example 3 1.761 531 Example 4 1.80 570 Example 5 1.79 560

[0096] The experimental results show that at a current density of 1000mA / cm 2 The electrode material prepared in this example has a lower overpotential, indicating that the catalyst layer prepared in this invention has high catalytic activity at high current density. Furthermore, the nickel-cobalt compound formed by selenium shedding in Example 1 has the lowest overpotential compared to nickel-iron and nickel-copper compounds.

[0097] In order to further verify the catalytic effect of this embodiment, the electrode materials of Examples 1-3 and Comparative Examples 2-4 were subjected to linear voltammetry tests under the same experimental conditions. The overpotential data at different current densities are shown in Table 2.

[0098] Table 2:

[0099] Group <![CDATA[Current density (mA cm -2 )]]> Overpotential (mV) Example 1 500 440 Example 2 500 460 Example 3 500 450 Comparative Example 2 500 520 Comparative Example 3 120 650 Comparative Example 4 80 570

[0100] The experimental results show that the catalysts prepared in Comparative Examples 2-4 have significantly higher overpotentials than that of this embodiment under the same test conditions, and their catalytic activities are relatively low.

[0101] Figure 9 The linear voltammetry (LSV) curves for Examples 1-3 and Comparative Example 2 provide a more intuitive illustration of the effectiveness of the present invention. The results demonstrate that the electrode materials of the present invention outperform existing products. Compared to the constant current deposition method of Comparative Example 2, the catalytic efficiency of the catalyst prepared by pulse electrodeposition of the present invention is significantly improved. In particular, the catalyst prepared in Example 1, using a pulse width of 2s and a pulse interval of 2s (a 1:1 time ratio), exhibits the highest catalytic activity.

[0102] The present invention further provides the electrode material of Example 1 at 1000mA / cm -2 Durability test was carried out within 24 hours under the following conditions. Figure 10 As can be seen from the IT test curve, the electrode material of Example 1 maintains a stable voltage of approximately 1.8V for 24 hours, demonstrating strong stability. This is due to the release of selenium phase species and the formation of oxygen vacancies, which maintain structural stability. This further demonstrates that the present invention combines high catalytic efficiency with strong stability, and has promising prospects for OER applications.

[0103] The above description is merely an example and illustration of the structure of the present invention, and the scope of protection of this patent is not limited thereto. Any modification, supplement, or replacement of the described specific embodiments by a person skilled in the art shall fall within the scope of protection of the present invention as long as it does not deviate from the structure of the present invention or exceed the scope defined by the claims.

Claims

1. A method for preparing an electrode material by pulse electrodeposition, characterized in that: include: (1) dissolving a transition metal salt and a selenium source in deionized water and stirring uniformly to prepare a precursor solution; (2) Using nickel foam as the working electrode and platinum sheet as the counter electrode, the precursor solution is added to the electrolytic cell to build a two-electrode electrolysis system; transition metal ions and selenium ions are co-deposited on the working electrode by pulse electrodeposition, forming a catalyst layer containing transition metal and selenide on the surface of the working electrode; (3) After cleaning the working electrode, it is immersed in alkaline solution together with the graphite counter electrode and the Hg / HgO reference electrode to jointly build an electrochemical system; the working electrode is electrochemically activated by cyclic voltammetry to induce the selenium phase in the catalyst layer of the working electrode to fall off; the surface of the catalyst layer is reconstructed to form a porous metal oxide, thereby obtaining an electrode material for the electrolysis of water and oxygen evolution reaction.

2. The method according to claim 1, characterized in that The transition metal is one or more of nickel, cobalt, iron or copper, and the transition metal salt is nitrate, chloride or acetate.

3. The method according to claim 1, characterized in that The selenium source is selenium dioxide. 4 . The method according to claim 1 , wherein in the precursor solution, the molar ratio of each transition metal ion to selenium ion is 1:

1.

5. The method according to claim 1, wherein In the step (2), before using the nickel foam, ultrasonic cleaning is performed with acetone, ethanol and deionized water for 10 to 30 minutes respectively, and then drying is performed at 60° C. for 30 to 60 minutes.

6. The method according to claim 1, characterized in that The alkali solution is a KOH solution with a concentration of 1M.

7. The method according to claim 1, characterized in that When pulse electrodeposition is used for co-deposition, the control parameters are: pulse current density 30mA / cm 2 , pulse width 2s, pulse interval 0.4~10s, total deposition time 360~1800s.

8. The method according to claim 1, characterized in that When the electrochemical activation treatment was performed by cyclic voltammetry, the control parameters were: scan rate 50 mV / s, scan range 0.3-1 V vs. Hg / HgO, and cycle number 50 times.

9. Use of the electrode material prepared by the method according to any one of claims 1 to 8 in oxygen evolution reaction by water electrolysis.

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