Preparation method and application of NiVOx / NiSe2 composite electrode material

Abstract

The invention relates to a preparation method and application of a NiVOx / NiSe2 composite electrode material, and belongs to the technical field of hydrogen energy, and the preparation method specifically comprises the following steps: (1) depositing a Ni (OH) 2 nanosheet on the surface of foamed nickel; (2) carrying out solvothermal selenylation treatment on Ni (OH) 2 to prepare a NiSe2 nano cubic box; and (3) electrochemically depositing NiVOx on the surface of the NiSe2 to obtain the NiVOx / NiSe2 composite electrode material. The electrochemical synthesis method adopted by the invention has the characteristics of simplicity, low cost and large scale, and the prepared composite electrode material has multiple catalytic active centers including water dissociation and hydrogen adsorption and desorption active sites. Compared with a traditional electrode, the composite electrode material disclosed by the invention shows remarkably enhanced alkaline hydrogen evolution catalytic performance, can be expanded to design of other catalytic materials, and provides a new thought for developing a cheap and efficient catalyst.

Description

Technical Field

[0001] The present invention belongs to the field of hydrogen energy technology, and specifically relates to a NiVO x Preparation method and application of / NiSe2 composite electrode material. Background Art

[0002] As an energy carrier for the conversion of renewable energy and electrical energy, hydrogen energy can achieve efficient and large-scale energy storage, and is an important carrier support for promoting the green and low-carbon transformation of energy-consuming terminals. The use of renewable energy (such as electricity generated by wind and solar energy) for alkaline water electrolysis to produce "green hydrogen" is a clean and sustainable method for preparing hydrogen. At present, Pt / C is considered to be the most effective HER catalyst. However, resource scarcity and high cost have severely limited its large-scale application. Therefore, it is crucial to develop cheap and efficient hydrogen evolution reaction catalysts.

[0003] To reduce hydrogen production costs and improve efficiency, researchers at home and abroad have recently developed a variety of non-precious metal hydrogen evolution catalysts to replace precious metal-based catalysts, including transition metal oxides, sulfides, selenides, and borides. Among these, transition metal selenides, particularly NiSe2, exhibit not only high chemical stability but also moderate adsorption energies with hydrogen, the intermediate product of hydrogen evolution, resulting in outstanding hydrogen evolution catalytic activity in acidic environments. However, NiSe2 exhibits poor intrinsic catalytic activity under alkaline conditions. This is primarily because in alkaline environments, hydrogen evolution efficiency depends primarily on the dissociation of HO and the adsorption capacity of reactants / intermediates on the catalyst surface. Furthermore, the alkaline HER intermediates H and OH exhibit a poor linear relationship. Consequently, traditional single-site electrode materials struggle to simultaneously lower the HO dissociation barrier and optimize hydrogen adsorption, making it difficult to achieve ideal hydrogen production efficiency. While transition metal oxides have low HO dissociation barriers, their strong adsorption of hydrogen leads to poor alkaline HER performance.

[0004] In view of the above problems, the present invention combines solvent thermal selenization and electrochemical deposition to synthesize NiSe2 with moderate hydrogen adsorption and NiVO with strong H2O dissociation ability. x Seamless integration, get NiVO x / NiSe2 composite electrode material. The present invention can also be extended to the design of other catalytic materials, providing a new idea for the development of cheap and efficient catalysts. Summary of the Invention

[0005] Aiming at the problem that alkaline electrode materials in the prior art have poor intrinsic hydrogen evolution catalytic activity, the present invention provides a NiVO xThe preparation method and application of / NiSe2 composite electrode materials use simple, low-cost, and easily scalable solvent thermal and electrochemical deposition methods to construct composite electrode materials to significantly improve alkaline hydrogen evolution performance.

[0006] A NiVO x The preparation method of the / NiSe2 composite electrode material specifically comprises the following steps:

[0007] (1) Preparation of Ni(OH)2 electrode: A Ni(OH)2 electrode was prepared by constant potential electrochemical deposition using pre-cleaned nickel foam as the working electrode, Ag / AgCl as the reference electrode, and a carbon rod as the counter electrode. The prepared electrode was then washed with water and ethanol and dried.

[0008] (2) Preparation of NiSe2 electrode: The Ni(OH)2 electrode prepared in step (1) was converted into NiSe2 electrode by solvent thermal selenization method, and then the prepared NiSe2 electrode was washed with water and ethanol respectively and dried;

[0009] (3) Preparation of NiVO x / NiSe2 composite electrode: The NiSe2 electrode prepared in step (2) was used as the working electrode, Ag / AgCl as the reference electrode, and the carbon rod as the counter electrode. NiVO was grown on the surface of the NiSe2 electrode by constant potential electrochemical deposition. x The prepared electrodes were then washed with water and ethanol and dried to obtain NiVO x / NiSe2 composite electrode.

[0010] in:

[0011] In the step (1), the applied constant potential is -0.6V to -1.3V vs. Ag / AgCl, the electrolyte is 1mmol / L to 100mmol / L Ni(NO3)2·6H2O solution, the temperature of the electrolyte is 5°C to 95°C, and the deposition time is 100s to 2000s.

[0012] In the steps (1), (2) and (3), the electrode is cleaned in water and ethanol 3 to 5 times; the drying process is carried out under vacuum conditions at a temperature of 60° C. to 120° C.

[0013] In step (2), the solvent thermal selenization method is specifically as follows: placing a Ni(OH)2 electrode in a mixed solution containing selenium powder, N,N-dimethylformamide, n-butylamine, and hydrazine hydrate, and performing a solvent thermal reaction at 100°C to 250°C for 0.5h to 5h to prepare a NiSe2 electrode;

[0014] The pH value of the mixed solution is 9-11, the volume ratio of N,N-dimethylformamide, n-butylamine and hydrazine hydrate in the mixed solution is (5-80):(0.1-5):(0.1-4), and the ratio of selenium powder to N,N-dimethylformamide is (0.1-2) g:(5-80) mL.

[0015] In the step (3), NiVO is deposited by constant potential electrochemical deposition. x The applied constant potential is -1.5V to -2.1V vs. Ag / AgCl, the electrolyte is 20mmol / L to 100mmol / L NiSO4·6H2O solution, 0mmol / L to 20mmol / L NH4VO3 solution and 1mmol / L to 100mmol / L H3BO3 solution, the temperature of the electrolyte is 5℃ to 95℃, and the deposition time is 100s to 2000s.

[0016] NiVO prepared by the above method x NiVO / NiSe2 composite electrode material with multiple catalytic active centers x / NiSe2, whose structure is based on nickel foam and has a rough surface NiVO x / NiSe2 nanocubic boxes are randomly distributed on the surface of nickel foam.

[0017] The above-mentioned NiVO x The application of / NiSe2 composite electrode material is specifically to use it in hydrogen production reaction.

[0018] Compared with the prior art, the present invention has the following beneficial effects:

[0019] 1. Compared with the traditional preparation method, the electrochemical synthesis method adopted in the present invention has the characteristics of simplicity, low cost and scalability, and the prepared NiVO x / NiSe2 composite electrode material has unique structure and morphology.

[0020] 2. Compared with the traditional single active site hydrogen evolution catalytic materials, the NiVO prepared in this invention x / NiSe2 electrode material has multiple catalytic active centers, including water dissociation and hydrogen adsorption and desorption active sites; the prepared NiVO x / NiSe2 electrode exhibits significantly enhanced alkaline hydrogen evolution catalytic performance compared with traditional electrodes. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 The NiSe2 electrode, Ni / NiSe2 electrode and NiVO prepared in Example 1 of the present invention x HER performance diagram of / NiSe2 composite electrode;

[0022] Figure 2 NiVO prepared in Example 1 of the present invention x SEM image of / NiSe2 composite electrode at 10,000 times magnification;

[0023] Figure 3 NiVO prepared in Example 1 of the present invention x SEM image of / NiSe2 composite electrode at 30,000 times magnification;

[0024] Figure 4 NiVO prepared in Example 1 of the present invention x SEM image of / NiSe2 composite electrode at 60,000 times magnification;

[0025] Figure 5 NiVO prepared in Example 1 of the present invention x TEM image of / NiSe2 composite electrode;

[0026] Figure 6 The NiSe2 electrode, Ni / NiSe2 electrode and NiVO prepared in Example 1 of the present invention x XRD pattern of / NiSe2 composite electrode;

[0027] Figure 7 NiVO prepared in Example 1 of the present invention x N2 adsorption-desorption curves of / NiSe2 composite electrode;

[0028] Figure 8 NiVO prepared in Example 1 of the present invention x Pore ​​size distribution curve of / NiSe2 composite electrode;

[0029] Figure 9 The NiSe2 electrode, Ni / NiSe2 electrode and NiVO prepared in Example 1 of the present invention x Tafel curve of NiSe2 composite electrode in 1 mol / L KOH solution;

[0030] Figure 10 Cyclic voltammetry curves of the NiSe2 electrode prepared in Example 1 of the present invention at different scan rates;

[0031] Figure 11 Curve showing the change of current density of the NiSe2 electrode prepared in Example 1 of the present invention as a function of scan rate;

[0032] Figure 12 Cyclic voltammetry curves of the Ni / NiSe2 electrode prepared in Example 1 of the present invention at different scan rates;

[0033] Figure 13Curve showing the variation of current density of the Ni / NiSe2 electrode prepared in Example 1 of the present invention with scan rate;

[0034] Figure 14 NiVO prepared in Example 1 of the present invention x Cyclic voltammetry curves of / NiSe2 composite electrode at different scan rates;

[0035] Figure 15 NiVO prepared in Example 1 of the present invention x Curve of the change of current density of / NiSe2 composite electrode with scan rate;

[0036] Figure 16 The NiSe2 electrode, Ni / NiSe2 electrode and NiVO prepared in Example 1 of the present invention x Electrochemical impedance curve of NiSe2 composite electrode in 1 mol / L KOH solution;

[0037] Figure 17 NiVO prepared in Example 1 of the present invention x Actual H2 production and related Faradaic efficiency diagram of the / NiSe2 composite electrode;

[0038] Figure 18 NiVO prepared in Example 1 of the present invention x Multi-step chronopotentiometry curves of the NiSe2 composite electrode in 1 mol / L KOH solution;

[0039] Figure 19 NiVO prepared in Example 1 of the present invention x Chronoamperometric curve of the NiSe2 composite electrode in 1 mol / L KOH solution. DETAILED DESCRIPTION

[0040] Example 1

[0041] A NiVO x The preparation method of the / NiSe2 composite electrode material specifically comprises the following steps:

[0042] (1) Preparation of Ni(OH)2 Electrode: Electrochemical deposition was performed using a three-electrode system. Pre-cleaned nickel foam was used as the working electrode, Ag / AgCl was used as the reference electrode, and a carbon rod was used as the counter electrode. The Ni(OH)2 electrode was prepared by potentiostatic electrochemical deposition at a constant potential of -0.95 V vs. Ag / AgCl. The electrolyte was a 40 mmol / L Ni(NO3)2·6H2O solution at a temperature of 25°C. The deposition time was 1000 s. The prepared electrode was washed four times with water and four times with ethanol, respectively, and dried in a vacuum drying oven at 80°C for 8 h.

[0043] (2) Preparation of NiSe2 electrode: The Ni(OH)2 electrode prepared in step (1) was converted into a NiSe2 electrode by solvent thermal selenization method. The prepared NiSe2 electrode was washed with water and ethanol four times respectively and dried in a vacuum drying oven at a drying temperature of 80°C for 8 hours.

[0044] The solvent thermal selenization method is specifically as follows: a Ni(OH)2 electrode is placed in a mixed solution containing 0.296g of selenium powder, 25mL of N,N-dimethylformamide, 0.5mL of n-butylamine, and 0.15mL of hydrazine hydrate, wherein the pH value of the mixed solution is 10, and a solvent thermal reaction is carried out at 180°C for 1h to prepare a NiSe2 electrode.

[0045] (3) Preparation of NiVO x / NiSe2 composite electrode: The NiSe2 electrode prepared in step (2) was used as the working electrode, Ag / AgCl as the reference electrode, and the carbon rod as the counter electrode. NiVO was grown on the surface of the NiSe2 electrode by constant potential electrochemical deposition. x The applied potential was -1.95 V vs. Ag / AgCl, the electrolyte was 38 mmol / L NiSO4·6H2O solution, 2 mmol / L NH4VO3 solution and 50 mmol / L H3BO3 solution, the electrolyte temperature was 25°C, and the deposition time was 600 s. The prepared electrode was washed with water and ethanol four times, and dried in a vacuum drying oven at 80°C for 8 h to obtain NiVO x / NiSe2 composite electrode.

[0046] In this example, a Ni / NiSe2 composite electrode was also prepared. The NiSe2 electrode prepared in step (2) was used as the working electrode, Ag / AgCl was used as the reference electrode, and a carbon rod was used as the counter electrode. Ni was grown on the surface of the NiSe2 electrode by constant potential electrochemical deposition. The applied constant potential was -1.95V vs. Ag / AgCl. The electrolyte was 38mmol / L NiSO4·6H2O solution and 50mmol / L H3BO3 solution. The electrolyte temperature was 25°C and the deposition time was 600s. The prepared electrode was washed with water and ethanol four times, respectively, and dried in a vacuum drying oven at 80°C for 8 hours to obtain a Ni / NiSe2 composite electrode.

[0047] NiVO prepared in Example 1 x NiVO / NiSe2 composite electrode material with multiple catalytic active centers x / NiSe2, whose structure is based on nickel foam and has a rough surface NiVO x / NiSe2 nanocubic boxes are randomly distributed on the surface of nickel foam, NiVO x The particle size of the / NiSe2 nanocube box is approximately 219nm~246nm.

[0048] The NiVO prepared in Example 1 x The NiSe2 / NiSe2 composite electrode material is used for hydrogen production reaction. It can achieve rapid hydrogen production in 1 mol / L KOH electrolyte, with an overpotential of only 48 mV to reach 10 mA cm -2 The current density is only 44mV dec. -1 The Faradaic efficiency is as high as 97%. After 50 hours of continuous water electrolysis, the current density does not show significant attenuation.

[0049] The specific content and implementation methods of the present invention are now further described in conjunction with the examples. However, the examples are only provided for illustration and cannot constitute a limitation on the technical solutions of the present invention. Examples 2 and 3 of the present invention are similar to Example 1 in content, and Example 1 is now used as an example for detailed description.

[0050] Structural and morphological characterization of composite electrode materials:

[0051] First, SEM and TEM images were used to analyze the NiVO x The morphology of the / NiSe2 composite electrode material was characterized, such as Figure 2 、 Figure 3 、 Figure 4 and Figure 5 As shown in the figure, a large number of rough-surfaced nanocubic boxes with a particle size of approximately 219nm to 246nm are randomly distributed on the nickel foam surface. The open nanopore structure between the cubic boxes facilitates the transport of substances during the electrocatalytic process, while the rough surface of the cubic boxes provides more catalytic active sites, accelerating the kinetics of the catalytic reaction. Figure 6 NiSe2 electrode, Ni / NiSe2 electrode and NiVO x / NiSe2 electrode material XRD spectrum, the above electrode material can be detected in the characteristic diffraction peak of cubic phase NiSe2 (JCPDS No.88-1711); it is worth noting that no NiVO x This is probably due to the formation of an amorphous structure. Figure 7 The N2 adsorption-desorption curve of NiVO x The BET surface area of ​​NiSe2 is 19 m 2 g -1 .according to Figure 8 The pore size distribution curve of NiVO xThere are a large number of mesopores in / NiSe2, with the pore diameter center at 3.7 nm. These mesopores are conducive to the transport of electrolyte and diffusion of gas during the electrocatalytic HER process.

[0052] The electrochemical properties of the composite electrode material prepared in Example 1 were characterized at room temperature:

[0053] Electrochemical experiments were carried out using a standard three-electrode test system. NiSe2 electrode, Ni / NiSe2 electrode and NiVO x HER performance of / NiSe2 composite electrode is shown in the figure Figure 1 As shown, NiVO x / NiSe2 electrode at 10 mA cm -2 The overpotential at this current density is only 48 mV, which is lower than 136 mV of NiSe2 and 80 mV of Ni / NiSe2. Figure 9 is the Tafel curve, NiSe2 electrode, Ni / NiSe2 electrode and NiVO x The Tafel slopes of the NiSe2 electrode materials are 85 mV dec -1 、72mV dec -1 and 44mV dec -1 The smaller Tafel slope indicates that NiVO x / NiSe2 has a faster hydrogen evolution catalytic reaction kinetics. For a specific electrode material, there is a linear relationship between double layer capacitance and electrochemical active area. Therefore, cyclic voltammetry was used to study the electrochemical properties of NiSe2, Ni / NiSe2 and NiVO in the non-Faraday range. x / NiSe2 electrode material electrochemically active area.

[0054] The cyclic voltammetry curves of the NiSe2 electrode prepared in Example 1 at different scan rates are as follows: Figure 10 The curve of current density changing with scan rate is shown in Figure 11 The cyclic voltammetry curves of Ni / NiSe2 electrode at different scan rates are shown in Figure 12 The curve of current density changing with scan rate is shown in Figure 13 As shown. NiVO x The cyclic voltammetry curves of the / NiSe2 composite electrode at different scan rates are shown in Figure 2. Figure 14 The curve of current density changing with scan rate is shown in Figure 15 As shown. NiSe2, Ni / NiSe2 and NiVO x The double layer capacitance of the / NiSe2 electrode materials is 19.3 mF cm -2 、20.4mF cm -2 、28.0mF cm -2 , indicating NiVOx / NiSe2 electrode material has the largest electrochemical active surface area and can provide more active sites for catalytic reactions.

[0055] In order to investigate the charge transfer dynamics at the electrode / electrolyte interface during the electrocatalytic hydrogen evolution reaction, an AC impedance test was performed. x The electrochemical impedance curve of the / NiSe2 composite electrode in 1 mol / L KOH solution is shown in Figure 16 As shown, NiVO x The charge transfer resistance of Ni / NiSe2 is only 26.1Ω, which is much lower than 131.5Ω of NiSe2 and 54.3Ω of Ni / NiSe2, indicating that it has faster charge transfer kinetics. x The actual H2 production of the / NiSe2 composite electrode and the related Faradaic efficiency are shown in the figure Figure 17 As shown in the figure, the results of gas chromatography showed that NiVO x The H2 production of / NiSe2 is basically consistent with the theoretical value, and the Faradaic efficiency is as high as 97%, which further confirms its high HER electrocatalytic activity.

[0056] To study NiVO x The material transport properties and durability of the NiSe2 / NiSe2 electrode were investigated by multi-step chronopotentiometry and chronoamperometry. Figure 18 It's NiVO x Multi-step chronopotentiometry curves of the / NiSe2 electrode, with the current density increasing from 50 mA cm in 8 steps -2 Increased to 800mA cm -2 , record the corresponding potential changes in this process. The first step is to -2 When the potential (without iR compensation) stabilizes, it then remains essentially constant for the remaining 500 s. The potential changes in the remaining steps also have similar behaviors, which indicates that NiVO x / NiSe2 electrode has faster ion migration kinetics and gas diffusion capacity. In addition, NiVO x The / NiSe2 electrode was continuously electrolyzed for 50 hours, and the current had almost no obvious decay. The chronoamperometric curve was as follows: Figure 19 As shown, it shows that NiVO x / NiSe2 electrode has excellent stability.

[0057] Example 2

[0058] A NiVO x The preparation method of the / NiSe2 composite electrode material specifically comprises the following steps:

[0059] (1) Preparation of Ni(OH)2 Electrode: Electrochemical deposition was performed using a three-electrode system. Pre-cleaned nickel foam was used as the working electrode, Ag / AgCl was used as the reference electrode, and a carbon rod was used as the counter electrode. The Ni(OH)2 electrode was prepared by potentiostatic electrochemical deposition at a constant potential of -1.2 V vs. Ag / AgCl. The electrolyte was a 10 mmol / L Ni(NO3)2·6H2O solution at a temperature of 20°C. The deposition time was 1500 s. The prepared electrode was washed four times with water and four times with ethanol, respectively, and dried in a vacuum drying oven at 100°C for 8 h.

[0060] (2) Preparation of NiSe2 electrode: The Ni(OH)2 electrode prepared in step (1) was converted into a NiSe2 electrode by solvent thermal selenization method. The prepared NiSe2 electrode was washed with water and ethanol four times respectively and dried in a vacuum drying oven at a drying temperature of 100°C for 8 hours.

[0061] The solvent thermal selenization method is specifically as follows: a Ni(OH)2 electrode is placed in a mixed solution containing 0.2g of selenium powder, 10mL of N,N-dimethylformamide, 1mL of n-butylamine, and 0.2mL of hydrazine hydrate, wherein the pH value of the mixed solution is 9, and a solvent thermal reaction is carried out at 200°C for 0.5h to prepare a NiSe2 electrode.

[0062] (3) Preparation of NiVO x / NiSe2 composite electrode: The NiSe2 electrode prepared in step (2) was used as the working electrode, Ag / AgCl as the reference electrode, and the carbon rod as the counter electrode. NiVO was grown on the surface of the NiSe2 electrode by constant potential electrochemical deposition. x The applied constant potential was -2.0 V vs. Ag / AgCl, the electrolyte was 40 mmol / L NiSO4·6H2O solution, 5 mmol / L NH4VO3 solution and 20 mmol / L H3BO3 solution, the electrolyte temperature was 20°C, and the deposition time was 1500 s. The prepared electrode was washed with water and ethanol four times, and dried in a vacuum drying oven at 100°C for 8 h to obtain NiVO x / NiSe2 composite electrode.

[0063] NiVO prepared in Example 2 x NiVO / NiSe2 composite electrode material with multiple catalytic active centers x / NiSe2, whose structure is based on nickel foam and has a rough surface NiVO x / NiSe2 nanocubic boxes are randomly distributed on the surface of nickel foam.

[0064] The NiVO prepared in Example 2x / NiSe2 composite electrode material is used for hydrogen production reaction, and rapid hydrogen production can be achieved in 1 mol / L KOH electrolyte.

[0065] Example 3

[0066] A NiVO x The preparation method of the / NiSe2 composite electrode material specifically comprises the following steps:

[0067] (1) Preparation of Ni(OH)2 Electrode: Electrochemical deposition was performed using a three-electrode system. Pre-cleaned nickel foam was used as the working electrode, Ag / AgCl was used as the reference electrode, and a carbon rod was used as the counter electrode. The Ni(OH)2 electrode was prepared by potentiostatic electrochemical deposition at a constant potential of -1.1 V vs. Ag / AgCl. The electrolyte was a 60 mmol / L Ni(NO3)2·6H2O solution at a temperature of 40°C. The deposition time was 1000 s. The prepared electrode was washed four times with water and four times with ethanol, respectively, and dried in a vacuum drying oven at 80°C for 8 h.

[0068] (2) Preparation of NiSe2 electrode: The Ni(OH)2 electrode prepared in step (1) was converted into a NiSe2 electrode by solvent thermal selenization method. The prepared NiSe2 electrode was washed with water and ethanol four times respectively and dried in a vacuum drying oven at a drying temperature of 80°C for 8 hours.

[0069] The solvent thermal selenization method is specifically as follows: a Ni(OH)2 electrode is placed in a mixed solution containing 0.4g selenium powder, 20mL N,N-dimethylformamide, 1mL n-butylamine, and 0.2mL hydrazine hydrate, wherein the pH value of the mixed solution is 9, and a solvent thermal reaction is carried out at 180°C for 2h to prepare a NiSe2 electrode.

[0070] (3) Preparation of NiVO x / NiSe2 composite electrode: The NiSe2 electrode prepared in step (2) was used as the working electrode, Ag / AgCl as the reference electrode, and the carbon rod as the counter electrode. NiVO was grown on the surface of the NiSe2 electrode by constant potential electrochemical deposition. x The applied constant potential was -1.9 V vs. Ag / AgCl, the electrolyte was 60 mmol / L NiSO4·6H2O solution, 5 mmol / L NH4VO3 solution and 30 mmol / L H3BO3 solution, the electrolyte temperature was 40°C, and the deposition time was 1000 s. The prepared electrode was washed with water and ethanol four times, and dried in a vacuum drying oven at 80°C for 8 hours to obtain NiVO x / NiSe2 composite electrode.

[0071] NiVO prepared in Example 3 x NiVO / NiSe2 composite electrode material with multiple catalytic active centers x / NiSe2, whose structure is based on nickel foam and has a rough surface NiVO x / NiSe2 nanocubic boxes are randomly distributed on the surface of nickel foam.

[0072] The NiVO prepared in Example 3 x / NiSe2 composite electrode material is used for hydrogen production reaction, and rapid hydrogen production can be achieved in 1 mol / L KOH electrolyte.

[0073] Example 4

[0074] A NiVO x The preparation method of the / NiSe2 composite electrode material specifically comprises the following steps:

[0075] (1) Preparation of Ni(OH)2 Electrode: Electrochemical deposition was performed using a three-electrode system. Pre-cleaned nickel foam was used as the working electrode, Ag / AgCl was used as the reference electrode, and a carbon rod was used as the counter electrode. The Ni(OH)2 electrode was prepared by potentiostatic electrochemical deposition at a constant potential of -0.95 V vs. Ag / AgCl. The electrolyte was a 40 mmol / L Ni(NO3)2·6H2O solution at a temperature of 25°C. The deposition time was 1000 s. The prepared electrode was washed four times with water and four times with ethanol, respectively, and dried in a vacuum drying oven at 80°C for 8 h.

[0076] (2) Preparation of NiSe2 electrode: The Ni(OH)2 electrode prepared in step (1) was converted into a NiSe2 electrode by solvent thermal selenization method. The prepared NiSe2 electrode was washed with water and ethanol four times respectively and dried in a vacuum drying oven at a drying temperature of 80°C for 8 hours.

[0077] The solvent thermal selenization method is specifically as follows: a Ni(OH)2 electrode is placed in a mixed solution containing 0.296g of selenium powder, 25mL of N,N-dimethylformamide, 0.5mL of n-butylamine, and 0.15mL of hydrazine hydrate, wherein the pH value of the mixed solution is 9, and a solvent thermal reaction is carried out at 180°C for 1h to prepare a NiSe2 electrode.

[0078] (3) Preparation of NiVO x / NiSe2 composite electrode: The NiSe2 electrode prepared in step (2) was used as the working electrode, Ag / AgCl as the reference electrode, and the carbon rod as the counter electrode. NiVO was grown on the surface of the NiSe2 electrode by constant potential electrochemical deposition. xThe applied constant potential was -1.95 V vs. Ag / AgCl, the electrolyte was 38 mmol / L NiSO4·6H2O solution, 2 mmol / L NH4VO3 solution and 50 mmol / L H3BO3 solution, the electrolyte temperature was 25°C, and the deposition time was 1000 s. The prepared electrode was washed with water and ethanol four times, and dried in a vacuum drying oven at 80°C for 8 hours to obtain NiVO x / NiSe2 composite electrode.

[0079] NiVO prepared in Example 4 x NiVO / NiSe2 composite electrode material with multiple catalytic active centers x / NiSe2, whose structure is based on nickel foam and has a rough surface NiVO x / NiSe2 nanocubic boxes are randomly distributed on the surface of nickel foam.

[0080] The NiVO prepared in Example 4 x / NiSe2 composite electrode material is used for hydrogen production reaction, and rapid hydrogen production can be achieved in 1 mol / L KOH electrolyte.

[0081] Example 5

[0082] A NiVO x The preparation method of the / NiSe2 composite electrode material specifically comprises the following steps:

[0083] (1) Preparation of Ni(OH)2 Electrode: Electrochemical deposition was performed using a three-electrode system. Pre-cleaned nickel foam was used as the working electrode, Ag / AgCl was used as the reference electrode, and a carbon rod was used as the counter electrode. The Ni(OH)2 electrode was prepared by potentiostatic electrochemical deposition at a constant potential of -0.95 V vs. Ag / AgCl. The electrolyte was a 40 mmol / L Ni(NO3)2·6H2O solution at a temperature of 25°C. The deposition time was 1000 s. The prepared electrode was washed four times with water and four times with ethanol, respectively, and dried in a vacuum drying oven at 80°C for 8 h.

[0084] (2) Preparation of NiSe2 electrode: The Ni(OH)2 electrode prepared in step (1) was converted into a NiSe2 electrode by solvent thermal selenization method. The prepared NiSe2 electrode was washed with water and ethanol four times respectively and dried in a vacuum drying oven at a drying temperature of 80°C for 8 hours.

[0085] The solvent thermal selenization method is specifically as follows: a Ni(OH)2 electrode is placed in a mixed solution containing 0.296g of selenium powder, 25mL of N,N-dimethylformamide, 0.5mL of n-butylamine, and 0.15mL of hydrazine hydrate, wherein the pH value of the mixed solution is 9, and a solvent thermal reaction is carried out at 180°C for 1h to prepare a NiSe2 electrode.

[0086] (3) Preparation of NiVO x / NiSe2 composite electrode: The NiSe2 electrode prepared in step (2) was used as the working electrode, Ag / AgCl as the reference electrode, and the carbon rod as the counter electrode. NiVO was grown on the surface of the NiSe2 electrode by constant potential electrochemical deposition. x The applied potential was -1.85 V vs. Ag / AgCl, the electrolyte was 38 mmol / L NiSO4·6H2O solution, 2 mmol / L NH4VO3 solution and 50 mmol / L H3BO3 solution, the electrolyte temperature was 25°C, and the deposition time was 600 s. The prepared electrode was washed with water and ethanol four times, and dried in a vacuum drying oven at 80°C for 8 h to obtain NiVO x / NiSe2 composite electrode.

[0087] NiVO prepared in Example 5 x NiVO / NiSe2 composite electrode material with multiple catalytic active centers x / NiSe2, whose structure is based on nickel foam and has a rough surface NiVO x / NiSe2 nanocubic boxes are randomly distributed on the surface of nickel foam.

[0088] The NiVO prepared in Example 5 x / NiSe2 composite electrode material is used for hydrogen production reaction, and rapid hydrogen production can be achieved in 1 mol / L KOH electrolyte.

[0089] Example 6

[0090] A NiVO x The preparation method of the / NiSe2 composite electrode material specifically comprises the following steps:

[0091] (1) Preparation of Ni(OH)2 Electrode: Electrochemical deposition was performed using a three-electrode system. Pre-cleaned nickel foam was used as the working electrode, Ag / AgCl was used as the reference electrode, and a carbon rod was used as the counter electrode. The Ni(OH)2 electrode was prepared by potentiostatic electrochemical deposition at a constant potential of -0.8 V vs. Ag / AgCl. The electrolyte was an 80 mmol / L Ni(NO3)2·6H2O solution at 80°C. The deposition time was 300 s. The prepared electrode was washed four times with water and four times with ethanol, respectively, and dried in a vacuum drying oven at 80°C for 8 h.

[0092] (2) Preparation of NiSe2 electrode: The Ni(OH)2 electrode prepared in step (1) was converted into a NiSe2 electrode by solvent thermal selenization method. The prepared NiSe2 electrode was washed with water and ethanol four times respectively and dried in a vacuum drying oven at a drying temperature of 80°C for 8 hours.

[0093] The solvent thermal selenization method is specifically as follows: a Ni(OH)2 electrode is placed in a mixed solution containing 1g of selenium powder, 40mL of N,N-dimethylformamide, 3mL of n-butylamine, and 2mL of hydrazine hydrate, wherein the pH value of the mixed solution is 10, and a solvent thermal reaction is carried out at 120°C for 4h to prepare a NiSe2 electrode.

[0094] (3) Preparation of NiVO x / NiSe2 composite electrode: The NiSe2 electrode prepared in step (2) was used as the working electrode, Ag / AgCl as the reference electrode, and the carbon rod as the counter electrode. NiVO was grown on the surface of the NiSe2 electrode by constant potential electrochemical deposition. x The applied constant potential was -1.6 V vs. Ag / AgCl, the electrolyte was 80 mmol / L NiSO4·6H2O solution, 10 mmol / L NH4VO3 solution and 80 mmol / L H3BO3 solution, the electrolyte temperature was 80°C, and the deposition time was 300 s. The prepared electrode was washed with water and ethanol four times, and dried in a vacuum drying oven at 80°C for 8 h to obtain NiVO x / NiSe2 composite electrode.

[0095] NiVO prepared in Example 6 x NiVO / NiSe2 composite electrode material with multiple catalytic active centers x / NiSe2, whose structure is based on nickel foam and has a rough surface NiVO x / NiSe2 nanocubic boxes are randomly distributed on the surface of nickel foam.

[0096] The NiVO prepared in Example 6x / NiSe2 composite electrode material is used for hydrogen production reaction, and rapid hydrogen production can be achieved in 1 mol / L KOH electrolyte.

[0097] Example 7

[0098] A NiVO x The preparation method of the / NiSe2 composite electrode material specifically comprises the following steps:

[0099] (1) Preparation of Ni(OH)2 Electrode: Electrochemical deposition was performed using a three-electrode system. Pre-cleaned nickel foam was used as the working electrode, Ag / AgCl was used as the reference electrode, and a carbon rod was used as the counter electrode. The Ni(OH)2 electrode was prepared by potentiostatic electrochemical deposition at a constant potential of -0.6 V vs. Ag / AgCl. The electrolyte was a 100 mmol / L Ni(NO3)2·6H2O solution at a temperature of 95°C. The deposition time was 100 s. The prepared electrode was washed four times with water and four times with ethanol, respectively, and dried in a vacuum drying oven at 80°C for 8 h.

[0100] (2) Preparation of NiSe2 electrode: The Ni(OH)2 electrode prepared in step (1) was converted into a NiSe2 electrode by solvent thermal selenization method. The prepared NiSe2 electrode was washed with water and ethanol four times respectively and dried in a vacuum drying oven at a drying temperature of 80°C for 8 hours.

[0101] The solvent thermal selenization method is specifically as follows: a Ni(OH)2 electrode is placed in a mixed solution containing 2g of selenium powder, 80mL of N,N-dimethylformamide, 5mL of n-butylamine, and 4mL of hydrazine hydrate, wherein the pH value of the mixed solution is 11, and a solvent thermal reaction is carried out at 100°C for 5h to prepare a NiSe2 electrode.

[0102] (3) Preparation of NiVO x / NiSe2 composite electrode: The NiSe2 electrode prepared in step (2) was used as the working electrode, Ag / AgCl as the reference electrode, and the carbon rod as the counter electrode. NiVO was grown on the surface of the NiSe2 electrode by constant potential electrochemical deposition. x The applied constant potential was -1.5V vs.Ag / AgCl, the electrolyte was 100mmol / L NiSO4·6H2O solution, 20mmol / L NH4VO3 solution and 100mmol / L H3BO3 solution, the electrolyte temperature was 95℃, and the deposition time was 100s. The prepared electrode was washed with water and ethanol four times respectively, and dried in a vacuum drying oven at 80℃ for 8h to obtain NiVO x / NiSe2 composite electrode.

[0103] NiVO prepared in Example 7 x NiVO / NiSe2 composite electrode material with multiple catalytic active centers x / NiSe2, whose structure is based on nickel foam and has a rough surface NiVO x / NiSe2 nanocubic boxes are randomly distributed on the surface of nickel foam.

[0104] The NiVO prepared in Example 7 x / NiSe2 composite electrode material is used for hydrogen production reaction, and rapid hydrogen production can be achieved in 1 mol / L KOH electrolyte.

[0105] Obviously, the above-mentioned embodiments of the present invention are merely examples for clearly illustrating the present invention, and are not limitations on the embodiments of the present invention. For ordinary technicians in the relevant field, other different forms of changes or modifications can be made based on the above description. It is impossible to list all the embodiments here. All obvious changes or modifications derived from the technical solution of the present invention are still within the scope of protection of the present invention.

Claims

1. A NiVO x The preparation method of / NiSe2 composite electrode material is characterized in that: The specific steps include: (1) Preparation of Ni(OH)2 electrode: A Ni(OH)2 electrode was prepared by constant potential electrochemical deposition using pre-cleaned nickel foam as the working electrode, Ag / AgCl as the reference electrode, and a carbon rod as the counter electrode. The prepared electrode was then washed with water and ethanol and dried. (2) Preparation of NiSe2 electrode: The Ni(OH)2 electrode prepared in step (1) was converted into a NiSe2 electrode by solvent thermal selenization method, and then the prepared NiSe2 electrode was washed with water and ethanol respectively and dried; (3) Preparation of NiVO x / NiSe2 composite electrode: The NiSe2 electrode prepared in step (2) was used as the working electrode, Ag / AgCl as the reference electrode, and the carbon rod as the counter electrode. NiVO was grown on the surface of the NiSe2 electrode by constant potential electrochemical deposition. x The prepared electrodes were then washed with water and ethanol and dried to obtain NiVO x / NiSe2 composite electrode.

2. The NiVO according to claim 1 x The preparation method of / NiSe2 composite electrode material is characterized in that: In the step (1), the applied constant potential is -0.6V to -1.3V vs. Ag / AgCl, the electrolyte is 1mmol / L to 100mmol / L Ni(NO3)2·6H2O solution, the temperature of the electrolyte is 5°C to 95°C, and the deposition time is 100s to 2000s.

3. The NiVO according to claim 1 x The preparation method of / NiSe2 composite electrode material is characterized in that: In the steps (1), (2) and (3), the electrode is cleaned in water and ethanol 3 to 5 times; the drying process is carried out under vacuum conditions at a temperature of 60° C. to 120° C.

4. The NiVO according to claim 1 x The preparation method of / NiSe2 composite electrode material is characterized in that: In step (2), the solvent thermal selenization method is specifically as follows: placing a Ni(OH)2 electrode in a mixed solution containing selenium powder, N,N-dimethylformamide, n-butylamine, and hydrazine hydrate, and performing a solvent thermal reaction at 100°C to 250°C for 0.5h to 5h to obtain a NiSe2 electrode.

5. The NiVO according to claim 4 x The preparation method of / NiSe2 composite electrode material is characterized in that: The pH value of the mixed solution is 9-11, the volume ratio of N,N-dimethylformamide, n-butylamine and hydrazine hydrate in the mixed solution is (5-80):(0.1-5):(0.1-4), and the ratio of selenium powder to N,N-dimethylformamide is (0.1-2) g:(5-80) mL.

6. The NiVO according to claim 1 x The preparation method of / NiSe2 composite electrode material is characterized in that: In the step (3), NiVO is deposited by constant potential electrochemical deposition. x The applied constant potential is -1.5V to -2.1V vs. Ag / AgCl, the electrolyte is 20mmol / L to 100mmol / L NiSO4·6H2O solution, 0mmol / L to 20mmol / L NH4VO3 solution and 1mmol / L to 100mmol / L H3BO3 solution, the temperature of the electrolyte is 5℃ to 95℃, and the deposition time is 100s to 2000s.

7. A NiVO x / NiSe2 composite electrode material, prepared by the method according to any one of claims 1 to 6, characterized in that: The NiVO x NiVO / NiSe2 composite electrode material with multiple catalytic active centers x / NiSe2, whose structure is based on nickel foam and has a rough surface NiVO x / NiSe2 nanocubic boxes are randomly distributed on the surface of nickel foam.

8. The NiVO according to claim 7 x Application of / NiSe2 composite electrode material, characterized in that, The composite electrode material is used for hydrogen production reaction.

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