Nickel-molybdenum hydrogen evolution electrode and preparation method and application thereof

Abstract

The invention discloses a nickel-molybdenum hydrogen evolution electrode and a preparation method and application thereof, and belongs to the technical field of water electrolysis hydrogen production. The preparation method of the nickel-molybdenum hydrogen evolution electrode provided by the invention comprises the following steps: carrying out alkali oil removal and acid activation treatment on a nickel net to obtain a pretreated nickel net; and the pretreated nickel net serves as a cathode, electrodeposition is conducted in electroplating liquid containing nickel sulfate hexahydrate, sodium molybdate dehydrate, sodium citrate dehydrate, boric acid, sodium chloride and an additive, separation and collection are conducted, and the nickel-molybdenum hydrogen evolution electrode is obtained. The overpotential of the prepared hydrogen evolution electrode material can be as low as 44 mV under the current density of 10 mA cm <-2 >, and the overpotential of the hydrogen evolution electrode material can be as low as 118.5 mV under the current density of 100 mA cm <-2 >. And under the current density of 100 mA cm <-2 > and in a 1 mol / L KOH solution at normal temperature, the material can stably run for more than 250 hours, has excellent stability, and has a wide application prospect in the field of hydrogen production by electrolysis of water.

Description

Technical Field

[0001] The present application belongs to the technical field of hydrogen production by electrolysis of water, and in particular relates to a nickel-molybdenum hydrogen evolution electrode and a preparation method and application thereof. Background Art

[0002] Traditional fossil fuels have played a vital role in the historical development of energy conversion. However, in the new context of growing energy demand and over-reliance on fossil fuels in the 21st century, it is crucial to explore sustainable strategies for the widespread application of new energy sources that can ensure both high energy density and environmental friendliness. In this context, suitable alternative energy sources are emerging in an endless stream, such as wind energy, solar energy, bioenergy, and especially hydrogen energy, which is widely regarded as one of the most promising energy sources due to its high energy density, abundant reserves, and environmental friendliness. The production, storage, transportation, and application of hydrogen energy have also become hot topics in the current energy field. Among the many hydrogen production methods, alkaline water electrolysis is extremely critical in hydrogen production due to its advantages such as high maturity, low cost, and ease of large-scale application. The hydrogen evolution reaction is the cathode reaction of water electrolysis for hydrogen production. Its overpotential and current density have a crucial influence on the energy consumption and hydrogen production rate of water electrolysis. Nickel-based hydrogen evolution electrode materials, such as nickel mesh, nickel foam, and NiAl, are commonly used in industry. However, due to the limited OER (anode reaction) activity of nickel itself, these electrode materials cannot meet the requirements of high current density water electrolysis for hydrogen production. Therefore, it is necessary to develop hydrogen evolution electrode materials with excellent comprehensive performance to expand their application range.

[0003] Existing technologies often use methods such as thermal spraying, hydrothermal deposition, or electrochemical deposition to prepare non-precious metal cathodes. While thermal spraying offers advantages such as the ability to process high-melting-point materials, flexible and controllable catalyst coating composition, and suitability for industrial mass production, the catalyst coating is only physically applied to the substrate surface, resulting in poor coating adhesion. The raw material melt state is unstable, resulting in an uneven catalyst microstructure. Furthermore, preparation requires high temperatures and high energy levels, requiring large amounts of raw materials and resulting in high process costs. Hydrothermal methods produce hydrogen evolution electrodes with excellent performance, but the preparation process consumes excessive energy, making large-scale industrial production difficult.

[0004] Electroplating technology, with its advantages such as excellent electrolyte mass transfer efficiency, microstructure designability, and process economy, has become an important technical path for the preparation of electrocatalytic materials. However, its practical application still faces technical bottlenecks such as significant coating thickness gradients caused by uneven edge current density distribution and insufficient coordinated optimization of chemical and mechanical stability.

[0005] For example, the prior art application with publication number CN 114250485 discloses a method for preparing a nickel-molybdenum-iron hydrogen evolution electrode with an ordered porous structure: a reduction electrode substrate is immersed as a cathode in an aqueous solution containing polymer microspheres and an alkali source for electrodeposition, and then the electrode substrate with the microsphere template attached is used as a cathode and electrodeposited in an alkaline aqueous solution containing a nickel source, a molybdenum source, sodium citrate, sodium chloride, and urea, and then immersed in a mixed solution containing an iron source to obtain a nickel-molybdenum-iron hydrogen evolution electrode.

[0006] However, the existing hydrogen evolution electrodes have the following problems: first, the introduction of iron increases the overpotential while reducing the stability of the material; second, the multi-step operation is cumbersome and difficult to achieve industrial production. Summary of the Invention

[0007] The present application discloses a nickel-molybdenum hydrogen evolution electrode and its preparation method and application, aiming to solve the technical problems of the existing hydrogen evolution electrode such as high overpotential, poor stability and complicated preparation process.

[0008] In order to achieve the above objectives, the technical solution of this application is:

[0009] A first aspect of the present application provides a method for preparing a nickel-molybdenum hydrogen evolution electrode, the method comprising:

[0010] The nickel mesh is subjected to alkali degreasing and acid activation treatment to obtain a pretreated nickel mesh;

[0011] The pretreated nickel mesh is used as a cathode and is electroplated in an electroplating solution containing nickel sulfate hexahydrate, sodium molybdate dihydrate, sodium citrate dihydrate, boric acid, sodium chloride and additives, and separated and collected to obtain a nickel-molybdenum hydrogen evolution electrode.

[0012] In combination with the first aspect, preferably, the additive is one or more of a brightener, a surface leveler, a cationic surfactant and an anionic surfactant;

[0013] The brightener is one or more of thiourea, coumarin, saccharin, bisbenzenesulfonimide, and propyl thioacetate;

[0014] The surface leveling agent is one or more of 1,4-butynediol, polyethylene glycol, and pyridine sulfonic acid;

[0015] The cationic surfactant is one or more of cetyltrimethylammonium chloride, cetyltrimethylammonium bromide, benzalkonium chloride, and cetylpyridinium chloride monohydrate;

[0016] The anionic surfactant is one or more of sodium lauryl sulfate, sodium dodecylbenzene sulfonate, and fatty alcohol polyoxyethylene ether phosphate.

[0017] In combination with the first aspect, preferably, the concentration of the additive is 0-0.8 g / L, and the amount of the additive added is not 0.

[0018] In combination with the first aspect, preferably, the mass concentration of the nickel sulfate hexahydrate is 40-160 g / L, the mass concentration of the boric acid is 5-15 g / L, and the mass concentration of the sodium chloride is 5-20 g / L.

[0019] In combination with the first aspect, preferably, the mass concentration of the sodium molybdate dihydrate is 5-40 g / L.

[0020] In combination with the first aspect, preferably, the mass concentration of the sodium citrate dihydrate is 20-50 g / L.

[0021] In combination with the first aspect, preferably, the conditions for the electrodeposition are: normal temperature, normal pressure, pH 3.0-6.0.

[0022] In combination with the first aspect, preferably, the conditions for the electrodeposition are: a current density of 20-140 mA cm -2 , the deposition time is 26-180min.

[0023] The second aspect of the present application provides a nickel-molybdenum hydrogen evolution electrode prepared by the preparation method described in the first aspect.

[0024] The third aspect of the present application provides the use of the nickel-molybdenum hydrogen evolution electrode prepared by the preparation method described in the first aspect or the nickel-molybdenum hydrogen evolution electrode described in the second aspect in the field of hydrogen production by electrolysis of water.

[0025] Compared with the prior art, the advantages or beneficial effects of the embodiments of the present application include at least:

[0026] The preparation method provided in this application uses the pretreated nickel mesh as the cathode and electro-deposits it in an electroplating solution containing nickel sulfate hexahydrate, sodium molybdate dihydrate, sodium citrate dihydrate, boric acid, sodium chloride, and additives to obtain a nickel-molybdenum hydrogen evolution electrode. On the one hand, due to the addition of additives, an adsorption layer can be formed on the cathode surface, which slows down the Ni 2+ The invention can realize rapid deposition, refine grains, and make the coating surface smoother; and can regulate the polarization effect of the electrodeposition process, reduce edge effects, make the coating more uniform, avoid local excessive thickness or thinness, and greatly reduce the overpotential of the hydrogen evolution electrode; on the other hand, it can reduce the internal stress of the coating, make the internal structure of the catalyst layer denser, avoid cracking or peeling of the coating, and enhance the mechanical stability and cycle stability of the nickel-molybdenum hydrogen evolution electrode; thirdly, it can make nickel shift to low binding energy and molybdenum shift to high binding energy, and at the same time increase the nickel content in the nickel-molybdenum hydrogen evolution electrode, greatly improving the catalytic efficiency; at the same time, the preparation process of the present application is simple to operate, the reaction conditions are mild, it is easy to implement, and has excellent prospects for industrial application. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] To more clearly illustrate the technical solutions of the embodiments of this application, the following briefly introduces the drawings required for describing the embodiments. Obviously, the drawings described below are only some of the embodiments described in this application. For those skilled in the art, other drawings can be derived from these drawings without inventive effort.

[0028] Figure 1 This is a scanning electron microscope image of the Al-nickel-molybdenum hydrogen evolution electrode prepared in an embodiment of the present application;

[0029] Figure 2 This is a scanning electron microscope image of the B1-nickel-molybdenum hydrogen evolution electrode prepared in an embodiment of the present application;

[0030] Figure 3 A scanning electron microscope image of a longitudinal cross-section of an Al-nickel-molybdenum hydrogen evolution electrode prepared in an embodiment of the present application;

[0031] Figure 4 This is a scanning electron microscope image of a longitudinal cross-section of a B1-nickel-molybdenum hydrogen evolution electrode prepared in an embodiment of the present application;

[0032] Figure 5 The linear scan curves of the A1-nickel-molybdenum hydrogen evolution electrode, B1-nickel-molybdenum hydrogen evolution electrode, and B2-hydrogen evolution electrode prepared in the examples of the present application were measured in a 1 mol / L KOH solution at room temperature at a scan rate of 5 mV / s.

[0033] Figure 6 Linear scan curves of the hydrogen evolution electrodes A1-nickel molybdenum hydrogen evolution electrode, A2-nickel molybdenum hydrogen evolution electrode, A3-nickel molybdenum hydrogen evolution electrode, A4-nickel molybdenum hydrogen evolution electrode, A5-nickel molybdenum hydrogen evolution electrode, A6-nickel molybdenum hydrogen evolution electrode, and A7-nickel molybdenum hydrogen evolution electrode prepared in the examples of the present application, measured in a 1 mol / L KOH solution at room temperature at a scan rate of 5 mV / s;

[0034] Figure 7 Linear scan curves of the A1-nickel-molybdenum hydrogen evolution electrode, A8-nickel-molybdenum hydrogen evolution electrode, A9-nickel-molybdenum hydrogen evolution electrode, A10-nickel-molybdenum hydrogen evolution electrode, and A11-nickel-molybdenum hydrogen evolution electrode prepared in the examples of the present application, measured in a 1 mol / L KOH solution at room temperature at a scan rate of 5 mV / s;

[0035] Figure 8 Linear scan curves of the A1-nickel-molybdenum hydrogen evolution electrode, A12-nickel-molybdenum hydrogen evolution electrode, A13-nickel-molybdenum hydrogen evolution electrode, and A14-nickel-molybdenum hydrogen evolution electrode prepared in the examples of the present application, measured in a 1 mol / L KOH solution at room temperature at a scan rate of 5 mV / s;

[0036] Figure 9 Linear scan curves of the A1-nickel-molybdenum hydrogen evolution electrode, B1-nickel-molybdenum hydrogen evolution electrode, A15-nickel-molybdenum hydrogen evolution electrode, and A16-nickel-molybdenum hydrogen evolution electrode prepared in the examples of the present application, measured in a 1 mol / L KOH solution at room temperature at a scan rate of 5 mV / s;

[0037] Figure 10 Linear scan curves of the A1-nickel-molybdenum hydrogen evolution electrode, A17-nickel-molybdenum hydrogen evolution electrode, A18-nickel-molybdenum hydrogen evolution electrode, and A19-nickel-molybdenum hydrogen evolution electrode prepared in the examples of the present application measured in a 1 mol / L KOH solution at room temperature at a scan rate of 5 mV / s;

[0038] Figure 11 Linear scan curves of the A1-nickel-molybdenum hydrogen evolution electrode, A20-nickel-molybdenum hydrogen evolution electrode, A21-nickel-molybdenum hydrogen evolution electrode, and A22-nickel-molybdenum hydrogen evolution electrode prepared in the examples of the present application measured in a 1 mol / L KOH solution at room temperature at a scan rate of 5 mV / s;

[0039] Figure 12 A1-nickel-platinum hydrogen evolution electrode, B1-nickel-platinum hydrogen evolution electrode, A23-nickel-platinum hydrogen evolution electrode, A24-nickel-platinum hydrogen evolution electrode, A25-nickel-platinum hydrogen evolution electrode, A26-nickel-platinum hydrogen evolution electrode, A27-nickel-platinum hydrogen evolution electrode and A28-nickel-platinum hydrogen evolution electrode were prepared for the embodiments of the present application, and linear scan curves of the hydrogen evolution electrodes were measured in a 1 mol / L KOH solution at room temperature at a scan rate of 5 mV / s;

[0040] Figure 13 XPS test graphs of A1-nickel-molybdenum hydrogen evolution electrode and B1-nickel-molybdenum hydrogen evolution electrode prepared in the examples of the present application;

[0041] Figure 14 The A1-nickel-molybdenum hydrogen evolution electrode and the B1-nickel-molybdenum hydrogen evolution electrode prepared in the embodiment of the present application were subjected to 100 mA cm-1 1 mol / L KOH solution at room temperature. -2 Stability test diagram under current density. DETAILED DESCRIPTION

[0042] The following will be combined with the accompanying drawings in the embodiments of this application to clearly and completely describe the technical solutions in the embodiments of this application. Obviously, the described embodiments are part of the embodiments of this application, not all of the embodiments. Based on the embodiments in this application, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of this application.

[0043] In the following description of this embodiment, the term "and / or" is used to describe the association relationship between associated objects, indicating that three possible relationships exist. For example, A and / or B can represent: A exists alone, B exists alone, and both A and B exist. A and B can be singular or plural. The character " / " generally indicates that the associated objects are in an "or" relationship.

[0044] In the following description of this embodiment, the term "at least one" refers to one or more, and "plurality" refers to two or more. "At least one of the following" or similar expressions refers to any combination of these items, including any combination of single items or plural items. For example, "at least one of a, b, or c", or "at least one of a, b, and c" can all represent: a, b, c, ab (i.e., a and b), ac, bc, or abc, where a, b, and c can be single or multiple.

[0045] Those skilled in the art should understand that in the following description of the embodiments of the present application, the order of serial numbers does not mean the order of execution, some or all of the steps can be executed in parallel or sequentially, and the execution order of each process should be determined by its function and internal logic, and should not constitute any limitation on the implementation process of the embodiments of the present application.

[0046] The terms used in the embodiments of the present application are only for the purpose of describing specific embodiments and are not intended to limit the present application. The singular forms "a", "an" and "the" used in the embodiments of the present application and the appended claims are also intended to include plural forms unless the context clearly indicates otherwise.

[0047] It should be noted that all raw materials and reagents in the examples of the present application were purchased on the market or prepared according to conventional methods well known to those skilled in the art.

[0048] In a first aspect, an embodiment of the present application provides a method for preparing a nickel-molybdenum hydrogen evolution electrode, the preparation method comprising:

[0049] The nickel mesh is subjected to alkali degreasing and acid activation treatment to obtain a pretreated nickel mesh;

[0050] The pretreated nickel mesh is used as a cathode and is electroplated in an electroplating solution containing nickel sulfate hexahydrate, sodium molybdate dihydrate, sodium citrate dihydrate, boric acid, sodium chloride and additives, and separated and collected to obtain a nickel-molybdenum hydrogen evolution electrode.

[0051] Among them, on the one hand, due to the addition of additives, an adsorption layer can be formed on the cathode surface to slow down the Ni 2+The invention can realize rapid deposition, refine grains, and make the coating surface smoother; and can regulate the polarization effect of the electrodeposition process, reduce edge effects, make the coating more uniform, avoid local excessive thickness or thinness, and greatly reduce the overpotential of the hydrogen evolution electrode; on the other hand, it can reduce the internal stress of the coating, make the internal structure of the catalyst layer denser, avoid cracking or peeling of the coating, and enhance the mechanical stability and cycle stability of the nickel-molybdenum hydrogen evolution electrode; thirdly, it can make nickel shift to low binding energy and molybdenum shift to high binding energy, and at the same time increase the nickel content in the nickel-molybdenum hydrogen evolution electrode, greatly improving the catalytic efficiency; at the same time, the preparation process of the present application is simple to operate, the reaction conditions are mild, it is easy to implement, and has excellent prospects for industrial application.

[0052] In the embodiments of the present application, the additive is preferably one or more of a brightener, a surface leveler, a cationic surfactant, and an anionic surfactant; the brightener is preferably one or more of thiourea, coumarin, saccharin, bisbenzenesulfonimide, and propyl thioacetate; the surface leveler is preferably one or more of 1,4-butynediol, polyethylene glycol, and pyridinesulfonic acid; the cationic surfactant is preferably one or more of cetyltrimethylammonium chloride, cetyltrimethylammonium bromide, benzalkonium chloride, and cetylpyridinium chloride monohydrate; the anionic surfactant is preferably one or more of sodium dodecyl sulfate, sodium dodecylbenzenesulfonate, and fatty alcohol polyoxyethylene ether phosphate. The addition of these additives can uniformly grow nickel-molybdenum nanomaterials on the surface of the bare nickel mesh, which have high hydrogen evolution catalytic activity and strong chemical stability under alkaline conditions.

[0053] In the embodiment of the present application, the concentration of the additive is preferably 0-0.8 g / L, and the amount of the additive added is not 0. By limiting the concentration of the additive, an adsorption layer can be formed on the cathode surface to slow down the Ni 2+ Rapid deposition refines grains and smooths the coating surface. By regulating the polarization during the electrodeposition process, it can reduce edge effects, resulting in a more uniform coating and preventing localized over-thickness or over-thinness. It can also reduce internal stress in the coating, making the catalyst layer's internal structure denser, preventing cracking or flaking, and enhancing the mechanical stability of the nickel-molybdenum hydrogen evolution electrode, making a significant contribution to its stability.

[0054] In the embodiment of the present application, the mass concentration of nickel sulfate hexahydrate is preferably 40-160 g / L. Among them, nickel sulfate hexahydrate is used as the main nickel salt in the electroplating process. By controlling the mass concentration of nickel sulfate hexahydrate, not only the Ni / Mo ratio in the coating can be adjusted, but also the high concentration Ni 2+ It can inhibit the excessive co-deposition of molybdenum and avoid the brittleness of the coating. It can also reduce the precipitation potential of Mo and promote the co-deposition of Ni-Mo.

[0055] In the embodiment of the present application, the mass concentration of the sodium molybdate dihydrate is preferably 5-40 g / L. 2+ Co-deposition achieves a reduction reaction. Adjusting the concentration of sodium molybdate dihydrate in the plating solution can prevent the coating from being too brittle and significantly improve the hardness and wear resistance of the coating.

[0056] In the embodiment of the present application, the mass concentration of the sodium citrate dihydrate is preferably 20-50g / L, the mass concentration of boric acid is preferably 5-15g / L, and the mass concentration of sodium chloride is preferably 5-20g / L. Wherein, sodium citrate dihydrate and boric acid are buffers, sodium citrate dihydrate serves as the main complexing agent, and boric acid serves as a weak complexing agent, which can form a soluble complex with metal ions, slow down the concentration of free metal ions in the plating solution, and make the coating more delicate and uniform. It effectively maintains the pH value of the plating solution stable, provides a relatively constant chemical environment for the deposition of metal ions, helps to improve the reproducibility and stability of electroplating, and reduces the deterioration of the coating quality caused by pH fluctuations.

[0057] In the embodiment of the present application, the conditions for the electrodeposition are preferably: normal temperature, normal pressure, pH 3.0-6.0. The current density is preferably 20-140 mA cm -2 The deposition time is preferably 26-180 min. By controlling the electrodeposition conditions, nickel-molybdenum nanomaterials can be uniformly grown on the surface of the bare nickel mesh, which has high hydrogen evolution catalytic activity and strong chemical stability under alkaline conditions.

[0058] It should be noted that this application uses non-precious metals nickel and molybdenum as raw materials. Compared with other hydrogen evolution electrodes loaded with precious metal elements, the raw materials are abundant and inexpensive, greatly reducing production costs. Furthermore, the nickel-molybdenum hydrogen evolution electrode is prepared by electroplating, which is simple to operate and has mild and easily achievable reaction conditions, showing great prospects for industrial application.

[0059] In the second aspect, the embodiment of the present application further provides a nickel-molybdenum hydrogen evolution electrode prepared by the preparation method described in the first aspect. The hydrogen evolution electrode material prepared based on the above preparation method has a current density of 10 mA cm -2 The overpotential can be as low as 44 mV at a current density of 100 mA cm -2 The overpotential can be as low as 118.5mV. -2 Under the current density and room temperature in 1mol / LKOH solution, it can operate stably for more than 250 hours, showing excellent stability.

[0060] In a third aspect, the present application also provides the use of the nickel-molybdenum hydrogen evolution electrode prepared by the preparation method described in the first aspect or the nickel-molybdenum hydrogen evolution electrode described in the second aspect in the field of hydrogen production by electrolysis of water. Among them, based on the greatly reduced hydrogen evolution overpotential and excellent cycle stability of the above-mentioned hydrogen evolution electrode, it can be widely used in the field of hydrogen production by electrolysis of water and has strong product competitiveness.

[0061] The technical solution of the present application will be further described below in conjunction with specific embodiments.

[0062] Example 1

[0063] This embodiment provides a method for preparing an Al-nickel-molybdenum hydrogen evolution electrode, which specifically includes:

[0064] S101: Nickel mesh pretreatment: a. Electrochemical degreasing: Prepare a solution of 5g / L NaOH, 2.5g / L Na2CO3, and 20g / L Na2SiO3 with deionized water. Set to volume and set aside. Immerse a pre-cut 1×1 nickel mesh as the cathode and a carbon rod as the anode in the degreasing solution. Set the degreasing temperature to 60°C and the current density to 40mA cm -2 , degreasing with constant current for 85s, and then washing with deionized water.

[0065] b. Strong acid removal of the oxide layer: Add 15 μL of 30% H2O2 solution and excess NaCl solid to 30 mL of 6 mol / L HCl solution to saturate the solution with NaCl. Place the nickel mesh treated in step a in the above solution and ultrasonicate for 60 seconds, then rinse with deionized water.

[0066] c. Weak acid etching: The nickel mesh treated in step b was placed in a 1 mol / L H2SO4 solution and ultrasonicated for 5 min, then washed with deionized water;

[0067] S102: nickel sulfate hexahydrate with a mass concentration of 100 g / L, sodium molybdate dihydrate with a mass concentration of 20 g / L, sodium citrate dihydrate with a mass concentration of 30 g / L, boric acid with a mass concentration of 15 g / L, and sodium chloride with a mass concentration of 10 g / L are prepared into a plating solution in a certain proportion, and the pH of the plating solution is adjusted to 4.0 with a 6 mol / L HCl solution and set aside; nickel and molybdenum are loaded on a nickel mesh substrate by electrochemical deposition: 50 mL of the above plating solution is taken into an electrolytic cell, 0.01 g of thiourea is added to the plating solution, a 1×1 nickel mesh and a 2×2 nickel mesh are used as a working electrode and a counter electrode, respectively, and nickel and molybdenum are deposited on the nickel mesh substrate by chronopotentiometry, and the current density used is 60 mA cm -2 The deposition time was 60 min. After rinsing with deionized water and ethanol, the electrode was dried with a hair dryer to obtain an A1-nickel-molybdenum hydrogen evolution electrode.

[0068] Example 2

[0069] This embodiment provides a method for preparing a nickel-molybdenum hydrogen evolution electrode. The component ratio, preparation operation, and process parameters are basically the same as those in Example 1, except that the mass concentration of nickel sulfate hexahydrate in the second step of this embodiment is 40, 60, 80, 120, 140, and 160 g / L, and accordingly, A2-nickel-molybdenum hydrogen evolution electrode, A3-nickel-molybdenum hydrogen evolution electrode, A4-nickel-molybdenum hydrogen evolution electrode, A5-nickel-molybdenum hydrogen evolution electrode, A6-nickel-molybdenum hydrogen evolution electrode, and A7-nickel-molybdenum hydrogen evolution electrode are obtained.

[0070] In order to verify the optimal concentration of nickel sulfate hexahydrate when preparing the nickel-molybdenum hydrogen evolution electrode in the embodiment of the present application, the nickel-molybdenum hydrogen evolution electrode prepared in the embodiment was tested, and the results were as follows: Figure 6 shown.

[0071] In the examples of this application, the area of ​​the catalyst working electrode is 1 cm 2 To make the electrochemical test data more comparable, the following examples were all conducted using a Shanghai Chenhua Instruments CHI 660F electrochemical workstation. The test conditions were as follows: a three-electrode system consisting of a hydrogen evolution electrode (HE) as the working electrode, a carbon rod as the counter electrode, and Hg / HgO as the reference electrode. The linear sweep curve of the HE was measured in a 1 mol / L KOH solution at room temperature at a scan rate of 5 mV / s.

[0072] according to Figure 6 The test results show that the electrochemical properties of A1-nickel molybdenum hydrogen evolution electrode, A2-nickel molybdenum hydrogen evolution electrode, A3-nickel molybdenum hydrogen evolution electrode, A4-nickel molybdenum hydrogen evolution electrode, A5-nickel molybdenum hydrogen evolution electrode, A6-nickel molybdenum hydrogen evolution electrode and A7-nickel molybdenum hydrogen evolution electrode were tested in 1 mol / L KOH solution with different contents of nickel sulfate hexahydrate. The electrochemical properties of A1-nickel molybdenum hydrogen evolution electrode were better than those of A2-nickel molybdenum hydrogen evolution electrode, A3-nickel molybdenum hydrogen evolution electrode, A4-nickel molybdenum hydrogen evolution electrode, A5-nickel molybdenum hydrogen evolution electrode, A6-nickel molybdenum hydrogen evolution electrode and A7-nickel molybdenum hydrogen evolution electrode at a current density of 10 mA cm -2 The overpotential is 44 mV at a current density of 100 mA cm -2 The overpotential at the hydrogen evolution electrode was 118.5 mV. The overpotential of the hydrogen evolution electrode first decreased and then increased with increasing nickel sulfate hexahydrate content. Therefore, the added nickel sulfate hexahydrate concentration was limited to 40-160 g / L, with the optimal concentration being 100 g / L.

[0073] Example 3

[0074] This embodiment provides a method for preparing a nickel-molybdenum hydrogen evolution electrode. The component ratio, preparation operation, and process parameters are basically the same as those in Example 1, except that the mass concentrations of sodium molybdate dihydrate in this embodiment are 5, 10, 30, and 40 g / L, respectively, to obtain A8-nickel-molybdenum hydrogen evolution electrode, A9-nickel-molybdenum hydrogen evolution electrode, A10-nickel-molybdenum hydrogen evolution electrode, and A11-nickel-molybdenum hydrogen evolution electrode, respectively.

[0075] In order to verify the optimal concentration of sodium molybdate dihydrate when preparing the nickel-molybdenum hydrogen evolution electrode in the embodiment of the present application, the nickel-molybdenum hydrogen evolution electrode prepared in the embodiment was tested, and the results were as follows: Figure 7 shown.

[0076] according to Figure 7 Test results show that when different amounts of nickel sulfate hexahydrate were added to test the electrochemical performance of A1-nickel-molybdenum hydrogen evolution electrodes, A8-nickel-molybdenum hydrogen evolution electrodes, A9-nickel-molybdenum hydrogen evolution electrodes, A10-nickel-molybdenum hydrogen evolution electrodes, and A11-nickel-molybdenum hydrogen evolution electrodes in a 1 mol / L KOH solution, the overpotential of the hydrogen evolution electrodes first decreased and then increased with increasing sodium molybdate dihydrate content. Therefore, the added mass concentration of sodium molybdate dihydrate was limited to 5-40g / L, with the optimal concentration being 20g / L.

[0077] Example 4

[0078] This embodiment provides a method for preparing a nickel-molybdenum hydrogen evolution electrode. The component ratio, preparation operation, and process parameters are basically the same as those in Example 1, except that the mass concentrations of sodium citrate dihydrate in this embodiment are 20, 40, and 50 g / L, respectively, to obtain A12-nickel-molybdenum hydrogen evolution electrode, A13-nickel-molybdenum hydrogen evolution electrode, and A14-nickel-molybdenum hydrogen evolution electrode, respectively.

[0079] In order to verify the optimal concentration of sodium citrate dihydrate when preparing the nickel-molybdenum hydrogen evolution electrode in the embodiment of the present application, the nickel-molybdenum hydrogen evolution electrode prepared in the embodiment was tested, and the results were as follows: Figure 8 shown.

[0080] according to Figure 8 Test results show that when different amounts of sodium citrate dihydrate were added to test the electrochemical performance of the A1-NiMo hydrogen evolution electrode, A12-NiMo hydrogen evolution electrode, A13-NiMo hydrogen evolution electrode, and A14-NiMo hydrogen evolution electrode in a 1 mol / L KOH solution, the overpotential of the hydrogen evolution electrode first decreased and then increased with increasing sodium citrate dihydrate content. Therefore, the added mass concentration of sodium citrate dihydrate was limited to 20-50 g / L, with the optimal concentration being 30 g / L.

[0081] Example 5

[0082] This embodiment provides a method for preparing a nickel-molybdenum hydrogen evolution electrode. The component ratio, preparation operation, and process parameters are basically the same as those in Example 1, except that the mass concentrations of thiourea in this embodiment are 0, 0.4, and 0.8 g / L, respectively. That is, 0, 0.02, and 0.04 g of thiourea are added to the plating solution, respectively, to obtain B1-nickel-molybdenum hydrogen evolution electrode, A15-nickel-molybdenum hydrogen evolution electrode, and A16-nickel-molybdenum hydrogen evolution electrode.

[0083] In order to verify the optimal concentration of thiourea when preparing the nickel-molybdenum hydrogen evolution electrode in the embodiment of the present application, the nickel-molybdenum hydrogen evolution electrode prepared in the embodiment was tested and the results were as follows: Figure 9 shown.

[0084] according to Figure 9 The test results show that when different contents of thiourea are added, the electrochemical performance of A1-nickel-molybdenum hydrogen evolution electrode, B1-nickel-molybdenum hydrogen evolution electrode, A15-nickel-molybdenum hydrogen evolution electrode and A16-nickel-molybdenum hydrogen evolution electrode are tested in 1 mol / L KOH solution. The overpotential of the hydrogen evolution electrode first decreases and then increases with the increase of thiourea content. The overpotential of the B1-nickel-molybdenum hydrogen evolution electrode at a current density of 10 mA cm -2 The overpotential is 76 mV at a current density of 100 mA cm -2 The overpotential under thiourea is 166 mV. Therefore, the added mass concentration of thiourea is limited to 0-0.8 g / L and the added amount is not 0, and the optimal concentration is 0.2 g / L.

[0085] Example 6

[0086] This embodiment provides a method for preparing a nickel-molybdenum hydrogen evolution electrode. The component ratio, preparation operation, and process parameters are basically the same as those in Example 1. The difference is that in this embodiment, the optimal pH of the electroplating solution is verified and the pH is adjusted to 3.0, 5.0, and 6.0, respectively, to obtain A17-nickel-molybdenum hydrogen evolution electrode, A18-nickel-molybdenum hydrogen evolution electrode, and A19-nickel-molybdenum hydrogen evolution electrode, respectively.

[0087] In order to verify the influence of the pH value of the electroplating solution when preparing the nickel-molybdenum hydrogen evolution electrode in the embodiment of the present application, the nickel-molybdenum hydrogen evolution electrode prepared in the embodiment was tested, and the results were as follows: Figure 10 shown.

[0088] according to Figure 10 The test results show that by adjusting the pH of the plating solution to different levels and testing the electrochemical performance of the A1-NiMo hydrogen evolution electrode, A17-NiMo hydrogen evolution electrode, A18-NiMo hydrogen evolution electrode, and A19-NiMo hydrogen evolution electrode in a 1 mol / L KOH solution, the overpotential of the hydrogen evolution electrode first decreases and then increases with increasing pH. Therefore, the pH of the plating solution is limited to 3.0-6.0, with the optimal pH being 4.0.

[0089] Example 7

[0090] This embodiment provides a method for preparing a nickel-molybdenum hydrogen evolution electrode. The composition ratio, preparation operation, and process parameters are basically the same as those in Example 1. The difference is that in this embodiment, the effects of different current densities and deposition times on the performance during electrodeposition are verified to ensure that the total charge during electroplating remains unchanged. The current densities used are adjusted to 20, 100, and 140 mA cm, respectively. -2, and the corresponding deposition times are 180, 36, and 26 min, and A20-nickel-molybdenum hydrogen evolution electrode, A21-nickel-molybdenum hydrogen evolution electrode, and A22-nickel-molybdenum hydrogen evolution electrode are obtained accordingly.

[0091] In order to verify the effects of different current densities and deposition times when preparing nickel-molybdenum hydrogen evolution electrodes in the examples of the present application, the nickel-molybdenum hydrogen evolution electrodes prepared in the examples were tested, and the results were as follows: Figure 11 shown.

[0092] according to Figure 11 The test results show that when the current density and deposition time are adjusted to different levels, the electrochemical performance of A1-NiMo hydrogen evolution electrode, A20-NiMo hydrogen evolution electrode, A21-NiMo hydrogen evolution electrode and A22-NiMo hydrogen evolution electrode are tested in 1 mol / L KOH solution. The overpotential of the hydrogen evolution electrode first decreases and then increases with the increase of the overpotential. Therefore, the current density during electrodeposition is limited to 20-140 mA cm -2 , the deposition time is 26-180 min, and the optimal condition is 60 mA cm -2 The deposition was carried out for 60 min at a current density of 100 nm.

[0093] Example 8

[0094] The component ratio, preparation operation and process parameters of the preparation method of the nickel-molybdenum hydrogen evolution electrode provided in this embodiment are basically the same as those in Example 1, except that different additives are added in this embodiment, namely 0.01g hexadecyltrimethylammonium chloride (1), 0.01g bisbenzenesulfonimide (2), 0.01g hexadecylpyridinium chloride monohydrate (3), 10 microliters of propyl thioacetate (4), 0.01g coumarin (5), 0.01g sodium lauryl sulfate (6), 0.01g thiourea (7), and no additive (8), and correspondingly A23-nickel-molybdenum hydrogen evolution electrode, A24-nickel-molybdenum hydrogen evolution electrode, A25-nickel-molybdenum hydrogen evolution electrode, A26-nickel-molybdenum hydrogen evolution electrode, A27-nickel-molybdenum hydrogen evolution electrode, A28-nickel-molybdenum hydrogen evolution electrode, A1-nickel-molybdenum hydrogen evolution electrode and B1-nickel-molybdenum hydrogen evolution electrode are obtained.

[0095] In order to verify the effect of different additives on the performance of the nickel-molybdenum hydrogen evolution electrode prepared in the embodiment of the present application, the nickel-molybdenum hydrogen evolution electrode prepared in the embodiment was tested, and the results were as follows: Figure 12 shown.

[0096] according to Figure 12The test results show that the electrochemical performance of the A1-NiMo hydrogen evolution electrode, B1-NiMo hydrogen evolution electrode, A23-NiMo hydrogen evolution electrode, A24-NiMo hydrogen evolution electrode, A25-NiMo hydrogen evolution electrode, A26-NiMo hydrogen evolution electrode, A27-NiMo hydrogen evolution electrode, and A28-NiMo hydrogen evolution electrode was tested in a 1 mol / L KOH solution. The different additives all promoted the hydrogen evolution performance of the hydrogen evolution electrodes to varying degrees. Therefore, the addition of special additives such as brighteners, levelers, and surfactants during the electrodeposition process is very beneficial to the preparation of hydrogen evolution electrodes.

[0097] At the same time, in order to verify the comprehensive performance of the nickel-molybdenum hydrogen evolution electrode prepared in the above embodiment, the present application provides the following comparative examples for detailed description.

[0098] Comparative Example 1

[0099] This comparative example provides a method for preparing a nickel-molybdenum hydrogen evolution electrode. The component ratio, preparation operation, and process parameters are basically the same as those in Example 1, except that sodium molybdate dihydrate is not added in the second step of this embodiment, and a B2-hydrogen evolution electrode is obtained accordingly.

[0100] In order to verify the appearance of the nickel-molybdenum hydrogen evolution electrode prepared above, a scanning electrolysis test was performed on it. The test results are as follows Figure 1-4 shown.

[0101] according to Figure 1 It can be seen from the scanning electron microscope image of the A1-nickel-molybdenum hydrogen evolution electrode prepared in Example 1 of the present application that after adding special additives, the surface morphology of the catalyst is relatively flat and evenly distributed on the bare nickel mesh substrate. Figure 3 This is a scanning electron microscope image of the longitudinal section of the A1-nickel-molybdenum hydrogen evolution electrode. After adding special additives, the bonding between the catalyst layer and the substrate is tighter, the catalyst layer is denser, and no holes or cracks appear.

[0102] according to Figure 2 It can be seen from the scanning electron microscope image of the B1-nickel-molybdenum hydrogen evolution electrode prepared in the embodiment of the present application that the catalyst layer without adding special additives has many protrusions on the surface, uneven bumps and uneven surface. Figure 4 This is a scanning electron microscope image of the longitudinal section of the B1-nickel-molybdenum hydrogen evolution electrode. There are many holes and cracks in the catalyst layer without adding special additives.

[0103] according to Figure 5 It can be seen that NiMo(+) / NM is A1-nickel molybdenum hydrogen evolution electrode, NiMo / NM is B1-nickel molybdenum hydrogen evolution electrode, Ni / NM is B2-hydrogen evolution electrode, NM is bare nickel mesh, and Pt / C is commercial 20wt% Pt / C. By comparison, it is found that the nickel molybdenum hydrogen evolution electrode with additives has excellent electrochemical properties.

[0104] In order to verify the structural characteristics of the nickel-molybdenum hydrogen evolution electrode, the prepared A1-nickel-molybdenum hydrogen evolution electrode and B1-nickel-molybdenum hydrogen evolution electrode were subjected to XPS tests.

[0105] according to Figure 13 It can be seen that the Ni 2p spectrum shows two peaks at 852.43 eV in sample NiMo(+) and 852.54 eV in sample NiMo, corresponding to Ni 0 2p 3 / 2 ; The other two peaks in sample NiMo(+) at 856.08 and 873.71 eV correspond to Ni 2+ 2p 3 / 2 and 2p 1 / 2 The other two peaks in the NiMo sample at 856.16 and 873.92 eV correspond to Ni 2+ 2p 3 / 2 and 2p 1 / 2 The Mo3d spectrum shows that the peak at 227.57 eV in the NiMo sample corresponds to the Mo 0 The other two peaks in NiMo(+) sample are located at 230.65 and 232.17 eV, which correspond to Mo 4+ 3d 5 / 2 and 3D 3 / 2 The two peaks at 230.90 and 232.07 eV in the NiMo sample correspond to Mo 4+ 3d 5 / 2 and 3D 3 / 2 The two peaks at 235.27 eV in NiMo(+) and 235.05 eV in NiMo correspond to Mo 6+ 3d 3 / 2 By analyzing the spectral data, it is found that after adding the additive, Ni moves to the lower binding energy and Mo moves to the higher binding energy. The electron transfer from Mo to Ni affects the reduction of metal ions during the deposition process. By semi-quantitative analysis of XPS data, it is found that after adding the special additive, the metal Ni / Mo ratio increases, and the Ni in the Ni element increases. 2+ Mo in Mo element 4+ The increase in the ratio further promotes the improvement of hydrogen evolution performance.

[0106] In order to verify the cycling stability of the nickel-molybdenum hydrogen evolution electrode, the prepared A1-nickel-molybdenum hydrogen evolution electrode was subjected to a cycling test.

[0107] according to Figure 14 It can be seen that the prepared A1-nickel-molybdenum hydrogen evolution electrode has good stability at 100 mA cm -2 Under the current density and room temperature in 1mol / LKOH solution, it can operate stably for more than 250 hours, showing good stability.

[0108] Therefore, the preparation method provided by this application uses the pretreated nickel mesh as the cathode and electroplates in an electroplating solution containing nickel sulfate hexahydrate, sodium molybdate dihydrate, sodium citrate dihydrate, boric acid, sodium chloride, and additives to obtain a nickel-molybdenum hydrogen evolution electrode. The hydrogen evolution electrode material prepared by this application has a current density of 10 mA cm -2 The overpotential can be as low as 44 mV at a current density of 100 mA cm -2 The overpotential can be as low as 118.5mV. -2 Under the current density and room temperature 1mol / LKOH solution, it can operate stably for more than 250 hours, has excellent stability, and has broad application prospects in the field of hydrogen production by water electrolysis.

[0109] The various embodiments in this specification are described in a progressive manner. The same or similar parts between the various embodiments can be referenced to each other, and each embodiment focuses on the differences from other embodiments.

[0110] The above embodiments are only used to illustrate the technical solutions of the present application, rather than to limit the present application. Although the present application has been described in detail with reference to the aforementioned embodiments, a person skilled in the art should understand that the technical solutions described in the aforementioned embodiments can still be modified, or some or all of the technical features therein can be replaced by equivalents. However, these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the present application.

Claims

1. A method for preparing a nickel-molybdenum hydrogen evolution electrode, characterized in that: The preparation method comprises: The nickel mesh is subjected to alkali degreasing and acid activation treatment to obtain a pretreated nickel mesh; The pretreated nickel mesh is used as a cathode and is electroplated in an electroplating solution containing nickel sulfate hexahydrate, sodium molybdate dihydrate, sodium citrate dihydrate, boric acid, sodium chloride and additives, and separated and collected to obtain a nickel-molybdenum hydrogen evolution electrode.

2. The method for preparing a nickel-molybdenum hydrogen evolution electrode according to claim 1, wherein The additive is one or more of a brightener, a surface leveler, a cationic surfactant and an anionic surfactant; The brightener is one or more of thiourea, coumarin, saccharin, bisbenzenesulfonimide, and propyl thioacetate; The surface leveling agent is one or more of 1,4-butynediol, polyethylene glycol, and pyridine sulfonic acid; The cationic surfactant is one or more of cetyltrimethylammonium chloride, cetyltrimethylammonium bromide, benzalkonium chloride, and cetylpyridinium chloride monohydrate; The anionic surfactant is one or more of sodium lauryl sulfate, sodium dodecylbenzene sulfonate, and fatty alcohol polyoxyethylene ether phosphate.

3. The method for preparing a nickel-molybdenum hydrogen evolution electrode according to claim 1, wherein The concentration of the additive is 0-0.8 g / L, and the amount of the additive added is not 0.

4. The method for preparing a nickel-molybdenum hydrogen evolution electrode according to claim 1, wherein The mass concentration of the nickel sulfate hexahydrate is 40-160 g / L, the mass concentration of the boric acid is 5-15 g / L, and the mass concentration of the sodium chloride is 5-20 g / L.

5. The method for preparing a nickel-molybdenum hydrogen evolution electrode according to claim 1, wherein The mass concentration of the sodium molybdate dihydrate is 5-40 g / L.

6. The method for preparing a nickel-molybdenum hydrogen evolution electrode according to claim 1, wherein: The mass concentration of the sodium citrate dihydrate is 20-50 g / L.

7. The method for preparing a nickel-molybdenum hydrogen evolution electrode according to claim 1, wherein: The conditions for the electrodeposition are: normal temperature, normal pressure, and pH 3.0-6.

0.

8. The method for preparing a nickel-molybdenum hydrogen evolution electrode according to claim 1, wherein: The conditions for the electrodeposition are: a current density of 20-140 mA cm -2 , the deposition time is 26-180min.

9. A nickel-molybdenum hydrogen evolution electrode prepared by the preparation method according to any one of claims 1 to 8.

10. Use of the nickel-molybdenum hydrogen evolution electrode prepared by the preparation method according to any one of claims 1 to 8 or the nickel-molybdenum hydrogen evolution electrode according to claim 9 in the field of hydrogen production by electrolysis of water.

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