Method for preparing Raney nickel electrode through electro-deposition of nickel-zinc alloy and application

Abstract

The invention discloses a method for preparing a Raney nickel electrode through electro-deposition of nickel-zinc alloy and application. The method comprises the steps that a nickel-based substrate is pretreated; the pretreated nickel-based substrate serves as a cathode, an electrochemical deposition reaction is carried out in an electrolytic bath containing electroplating liquid, and the electroplating liquid comprises nickel salt and zinc salt; carrying out heat treatment on the nickel-based substrate subjected to electrochemical deposition; and activating the nickel-based substrate subjected to heat treatment to remove the zinc element to obtain the Raney nickel electrode. According to the Raney nickel electrode, valence electrons can be redistributed by depositing the nickel-zinc alloy phase on the nickel substrate, so that electron transmission is accelerated, and the conductivity of the electrode is improved; the nickel-zinc alloy is slow and uniform in reaction in the activation process, nickel-zinc crystal nucleuses can be uniformly nucleated and grow, and a uniform pore structure can be formed after activation, so that the active area of the catalyst is greatly increased, and the hydrogen reaction rate is increased.

Description

Technical Field

[0001] The present application belongs to the technical field of alkaline water electrolysis, and specifically relates to a method for preparing a Raney nickel electrode by electrodeposition of a nickel-zinc alloy and its application. Background Art

[0002] At present, the mainstream hydrogen production technology is mainly based on traditional fossil energy as raw materials. Although this method is mature and easy to scale up, it does not meet the requirements of environmental protection and sustainable development. Alkaline water electrolysis hydrogen production technology is both environmentally friendly and low-cost, and can produce high-purity hydrogen. The technology is relatively mature. The water electrolysis reaction consists of two half reactions, the hydrogen evolution reaction (HER) occurring at the cathode and the oxygen evolution reaction (OER) occurring at the anode, with a theoretical voltage of 1.23V; because the process is usually affected by factors such as polarization, a certain overpotential is required to decompose water into hydrogen and oxygen.

[0003] In order to reduce the overpotential required for the electrolysis of water, a catalyst needs to be coated on the electrode surface to accelerate the reaction. Currently, the most widely used commercial catalyst is the Raney nickel catalyst, and its preparation method is mainly to spray a Raney nickel catalyst with a certain nickel-aluminum ratio on a nickel-based substrate by thermal spraying, plasma spraying, etc., so that the nickel-based electrode has higher catalytic activity. However, the existing nickel-aluminum Raney nickel catalyst reacts violently during the activation process. Due to the rapid reaction, the new phase crystal nucleus is non-uniformly nucleated and grown, and the crystal nucleus is mainly concentrated in solid impurities or near the surface, which is easily affected by impurities, has poor stability, and the pores formed are uneven, which affects the performance and service life of the electrode. Summary of the invention

[0004] The purpose of the present application is to provide a method and application for preparing a Raney nickel electrode by electrodeposition of nickel-zinc alloy, so as to solve the technical problems in the prior art that the nickel-aluminum-Raney nickel catalyst reacts violently during the activation process, resulting in non-uniform nucleation and growth of new phase crystal nuclei, and the crystal nuclei are mainly concentrated in solid impurities or near the surface, which are easily affected by impurities, have poor stability, and the pores formed are uneven, which affects the performance and service life of the electrode.

[0005] In order to achieve the above-mentioned object, the first aspect of the present application provides a method for preparing a Raney nickel electrode by electrodeposition of a nickel-zinc alloy, comprising:

[0006] Pre-treating the nickel-based substrate;

[0007] Using the pretreated nickel-based substrate as a cathode, and performing an electrochemical deposition reaction in an electrolytic cell filled with an electroplating solution, wherein the electroplating solution includes a nickel salt and a zinc salt;

[0008] heat treating the electrochemically deposited nickel-based substrate;

[0009] The heat-treated nickel-based substrate is activated to remove the zinc element and obtain a Raney nickel electrode.

[0010] In one or more embodiments, the solvent of the electroplating solution is water, the solute consists of nickel salt, zinc salt, boric acid and ammonium chloride, and the pH value of the electroplating solution is 4-6.

[0011] In one or more embodiments, the concentration of the nickel salt is 50-150 g / L, the concentration of the zinc salt is 1-10 g / L, the concentration of the boric acid is 10-50 g / L, and the concentration of the ammonium chloride is 10-100 g / L.

[0012] In one or more embodiments, the nickel salt is nickel sulfate, and the zinc salt is zinc chloride.

[0013] In one or more embodiments, the step of pretreating the nickel-based substrate comprises:

[0014] The nickel-based substrate is subjected to sandblasting treatment, and then a surfactant is added to perform ultrasonic treatment;

[0015] The ultrasonically treated nickel-based substrate was immersed in acid.

[0016] In one or more embodiments, the nickel-based substrate is a nickel mesh. In the electrochemical deposition reaction, the anode includes two nickel-based stretched meshes with the same area as the nickel mesh. The two nickel-based stretched meshes are symmetrically arranged on both sides of the nickel mesh, and the nickel mesh is located on the connecting line of the two nickel-based stretched meshes.

[0017] In one or more embodiments, the electrochemical deposition reaction uses a constant current with a current density of 5 to 20 mA / cm 2 The reaction time is 1 to 2 hours and the reaction temperature is room temperature.

[0018] In one or more embodiments, the heat treatment is performed at a temperature of 250 to 500° C. for a time of 1 to 2 hours.

[0019] In one or more embodiments, the step of activating the heat-treated nickel-based substrate is specifically: immersing the nickel-based substrate in an activation solution until no bubbles are precipitated;

[0020] The activation solution comprises a sodium hydroxide solution and an additive, wherein the additive accounts for 5 to 15 wt % of the activation solution, and the additive comprises the following components in parts by weight:

[0021] 10-50 parts of organic solvent, 2-8 parts of Triton 100, 5-10 parts of sodium myristate and 7-15 parts of sodium citrate.

[0022] In order to achieve the above-mentioned purpose, the second aspect of the present application provides a Raney nickel electrode prepared by the method described in any of the above-mentioned embodiments.

[0023] In order to achieve the above-mentioned purpose, the third aspect of the present application provides an application of the Raney nickel electrode described in any of the above-mentioned embodiments as a hydrogen evolution electrode in an alkaline water electrolysis reaction.

[0024] Different from the prior art, the beneficial effects of this application are:

[0025] The Raney nickel electrode of the present application can realize redistribution of valence electrons by depositing a nickel-zinc alloy phase on a nickel substrate, thereby accelerating electron transport and improving the conductivity of the electrode; since the nickel-zinc alloy reacts slowly and evenly during the activation process, the nickel-zinc crystal nuclei can be uniformly nucleated and grown, and a uniform pore structure can be formed after activation, which greatly increases the active area of ​​the catalyst and improves the hydrogen reaction rate;

[0026] The raw material cost of the Raney nickel electrode of the present application is low, it is easy to use commercially, and has good prospects in the alkaline water hydrogen production industry;

[0027] The Raney nickel electrode of the present application is 500mA / cm 2 The overpotential at a current density of 240 mV is 28% lower than that of the conventional thermal sprayed Raney nickel electrode; the electrochemically active area of ​​the Raney nickel electrode of the present application is 55 times that of the bare nickel mesh and 1.6 times that of the conventional thermal sprayed Raney nickel electrode, with a higher active area and stronger catalytic performance. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments recorded in the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0029] Figure 1 It is a schematic flow chart of an embodiment of a method for preparing a Raney nickel electrode by electrodeposition of a nickel-zinc alloy according to the present application;

[0030] Figure 2 is a SEM image of the Raney nickel electrode prepared in Example 1 of the present application;

[0031] Figure 3 is the LSV curve of Examples 1 to 3 of the present application and Comparative Example 1;

[0032] Figure 4 It is the double-layer capacitance curve of Example 1, Comparative Example 1 and the bare nickel mesh. DETAILED DESCRIPTION

[0033] In order to enable those skilled in the art to better understand the technical solutions in the present application, the technical solutions in the embodiments of the present application will be clearly and completely described below in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in the field without creative work should fall within the scope of protection of the present application.

[0034] At present, the widely used Raney nickel electrode is prepared by thermal spraying nickel-aluminum alloy. The activation reaction is rapid during the removal of aluminum, and the nickel-aluminum phase nuclei are non-uniformly nucleated and grown. After activation, uneven pore morphology appears, the performance is difficult to improve, and the coating life is limited.

[0035] In order to solve the above problems, the applicant has developed a new method for preparing Raney nickel electrode, which can effectively solve the problem of uneven pores caused by non-uniform nucleation and growth during the activation process, thereby greatly increasing the active area of ​​the catalyst and improving the catalytic activity.

[0036] Specifically, see Figure 1 , Figure 1 It is a schematic flow chart of an embodiment of a method for preparing a Raney nickel electrode by electroplating a nickel-zinc alloy in the present application.

[0037] like Figure 1 As shown, the method includes:

[0038] S100, pre-treating the nickel-based substrate.

[0039] The nickel-based substrate may be a commonly used substrate material in the art, such as nickel mesh, nickel foam, and nickel felt.

[0040] The purpose of pretreatment is to remove impurities such as oil stains and oxide layers remaining on the surface of the nickel-based substrate to avoid affecting the adhesion of subsequent plating layers on the nickel-based substrate and to improve the bonding strength of the electroplated coating.

[0041] Specifically, in one embodiment, the preprocessing method may include:

[0042] The nickel-based substrate was sandblasted and then ultrasonicated with the addition of a surfactant to remove surface oil stains;

[0043] The ultrasonically treated nickel-based substrate was immersed in acid to remove the surface oxide layer.

[0044] The ultrasonic treatment time can be 30 minutes, the acid can be any commonly used acid such as hydrochloric acid, and the soaking time can be 10 minutes, as long as the oil stains and the oxide layer are removed.

[0045] In other embodiments, other pretreatment methods commonly used in the art may also be used to ensure that the oil stains and oxide layer on the surface of the nickel-based substrate are fully removed, and the effect of this embodiment can be achieved.

[0046] S200, using the pretreated nickel-based substrate as a cathode to perform an electrochemical deposition reaction in an electrolytic cell filled with an electroplating solution.

[0047] The electroplating solution includes nickel salt and zinc salt, so that a coating including nickel and zinc can be deposited on the surface of the nickel-based substrate in an electrochemical deposition reaction.

[0048] In one embodiment, the solvent of the electroplating solution may be water, the solute may include nickel salt, zinc salt, boric acid and ammonium chloride, and the pH value of the electroplating solution may be 4-6.

[0049] More specifically, in order to ensure a suitable ratio of nickel to zinc, which helps to optimize the pore ratio and distribution of the subsequently prepared Raney nickel electrode, the concentration of the nickel salt in the electroplating solution can be 50-150 g / L, the concentration of the zinc salt can be 1-10 g / L, the concentration of the boric acid can be 10-50 g / L, and the concentration of the ammonium chloride can be 10-100 g / L.

[0050] Among them, the nickel salt can be a commonly used soluble nickel salt such as nickel sulfate, nickel chloride, nickel nitrate, etc., and the zinc salt can be a commonly used soluble zinc salt such as zinc sulfate, zinc chloride, zinc nitrate, etc. In a preferred embodiment, the nickel salt can be nickel sulfate, and the zinc salt can be zinc chloride.

[0051] The anode used in the above electrochemical deposition reaction can be anode materials commonly used in the art, such as nickel, zinc, and platinum.

[0052] In one embodiment, when the nickel-based substrate is a nickel mesh, in order to optimize the rate and effect of the electrochemical deposition reaction, the anode can use two nickel-based stretched meshes with the same area as the nickel mesh. The two nickel-based stretched meshes are symmetrically arranged on both sides of the nickel mesh, and the nickel mesh is located on the connecting line of the two nickel-based stretched meshes, thereby ensuring that the current inside the electrolytic cell is evenly distributed to obtain a uniform coating.

[0053] In one embodiment, the electrochemical deposition reaction can be carried out using a constant current, and the current density can be 5-20 mA / cm 2 The reaction time can be 1 to 2 hours, and the reaction temperature can be room temperature.

[0054] S300, heat treating the electrochemically deposited nickel-based substrate.

[0055] In S200, nickel and zinc are deposited on the surface of the nickel-based substrate. Further, the nickel-based substrate needs to be heat treated to optimize the electronic structure so as to form a nickel-zinc alloy phase on the surface.

[0056] In one embodiment, the heat treatment temperature may be 250-500° C. and the time may be 1-2 hours.

[0057] S400, activating the heat-treated nickel-based substrate to remove the zinc element to obtain a Raney nickel electrode.

[0058] After the nickel-zinc alloy phase is formed in S300, the zinc element in the nickel-zinc alloy can be removed by activation to construct a porous structure, thereby increasing the catalyst active area on the surface of the nickel-based substrate.

[0059] Since the nickel-zinc alloy reacts evenly and slowly during the activation process, the nickel-zinc crystal nuclei can be uniformly nucleated and grown, forming a uniform pore structure after activation, thus solving the problem of uneven pores after activation in the existing Raney nickel catalyst, which affects the catalytic performance and coating life.

[0060] In one embodiment, the method for activating the nickel-based substrate may specifically include: immersing the nickel-based substrate in an activation solution until no bubbles are precipitated.

[0061] In one embodiment, the activation solution may be a commonly used KOH activation solution;

[0062] In another embodiment, in order to optimize the activation effect and improve the catalytic performance, the activation solution may include a sodium hydroxide solution and an additive, the additive accounting for 5 to 15 wt % of the activation solution, and the additive includes the following components in parts by weight: 10 to 50 parts of an organic solvent, 2 to 8 parts of Triton 100, 5 to 10 parts of sodium myristate and 7 to 15 parts of sodium citrate.

[0063] The Raney nickel electrode prepared based on the above-mentioned embodiments can realize redistribution of valence electrons by depositing a nickel-zinc alloy phase on a nickel substrate, thereby accelerating electron transport and improving the conductivity of the electrode; since the nickel-zinc alloy reacts slowly and evenly during the activation process, the nickel-zinc crystal nuclei can nucleate and grow evenly, forming a uniform pore structure after activation, greatly increasing the active area of ​​the catalyst and improving the hydrogen reaction rate.

[0064] The effects of the technical solution of the present application are further described in detail below in conjunction with specific embodiments.

[0065] Embodiment 1:

[0066] A Raney nickel electrode is prepared by the following steps:

[0067] 1. Take 1L of deionized water and add it to a beaker. Add 100g of nickel sulfate, 30g of boric acid, 50g of ammonium chloride and 5g of zinc chloride. Stir and dissolve. After fully dissolving, adjust the pH value to between 4.5 and 5.5 to obtain an electroplating solution.

[0068] 2. Select a nickel mesh with a wire diameter of 46 meshes and a size of 0.25mm and a size of 10*12cm. First, perform double-sided sandblasting, then put it in a surfactant for 30 minutes of ultrasonic treatment to remove oil stains on the surface of the nickel mesh, and then soak the nickel mesh in 3M hydrochloric acid for 10 minutes to remove the surface oxide layer;

[0069] 3. Use the treated nickel mesh as the cathode, and select two nickel-based stretched meshes of the same area as the anode. Place the cathode in the middle of the electrolytic cell filled with electroplating solution. Place the two anodes symmetrically on both sides of the cathode, and the cathode is located on the connecting line of the two anodes. Connect the cathode to the negative pole of the DC power supply, and the anode to the positive pole of the DC power supply. At a current density of 20mA / cm 2 The electrochemical deposition reaction was started under a constant current of , the reaction time was 2 h, and the reaction temperature was room temperature;

[0070] 4. Place the electrochemically deposited nickel mesh in a muffle furnace for heat treatment at a heating rate of 5°C / min, a treatment temperature of 400°C, and a treatment time of 1h;

[0071] 5. The heat-treated nickel mesh is placed in an activation solution for activation until no bubbles are precipitated to obtain a Raney nickel electrode, wherein the activation solution comprises 80 parts by weight of an additive and 1000 parts by weight of a 25wt% sodium hydroxide solution, which are evenly mixed, and the additive comprises 15 parts by weight of ethanol, 10 parts by weight of isopropanol, 46 parts by weight of deionized water, 8 parts by weight of Triton 100, 9 parts by weight of sodium myristate, and 12 parts by weight of sodium citrate.

[0072] Embodiment 2:

[0073] A Raney nickel electrode is prepared by the same method as in Example 1, except that: in the electroplating solution of Example 2, the amount of zinc chloride added is 10 g, the amount of nickel sulfate added is 150 g, and the amount of ammonium chloride added is 10 g.

[0074] Embodiment 3:

[0075] A Raney nickel electrode, the preparation method is basically the same as that of Example 1, except that the current density of the electrochemical deposition reaction in Example 3 is 5 mA / cm 2 The amount of nickel sulfate added to the electroplating solution is 50g, the amount of zinc chloride added is 1g, and the amount of boric acid added is 50g.

[0076] Embodiment 4:

[0077] A Raney nickel electrode, the preparation method is basically the same as that of Example 1, except that: the reaction time of the electrochemical deposition reaction in Example 4 is 1 hour, the amount of boric acid added to the electroplating solution is 10g, and the amount of ammonium chloride added is 100g.

[0078] Embodiment 5:

[0079] A Raney nickel electrode is prepared by a method substantially the same as that of Example 1, except that the heat treatment temperature of Example 5 is 300° C., and the amount of boric acid added to the electroplating solution is 50 g.

[0080] Embodiment 6:

[0081] A Raney nickel electrode, the preparation method is basically the same as that of Example 1, except that: the heat treatment time of Example 6 is 2 hours.

[0082] Embodiment 7:

[0083] A Raney nickel electrode, the preparation method is basically the same as that of Example 1, except that: the amount of zinc chloride added to the electroplating solution of Example 7 is 10g, and the current density of the electrochemical deposition reaction is 5mA / cm 2 .

[0084] Embodiment 8:

[0085] A Raney nickel electrode, the preparation method is basically the same as that of Example 1, except that the current density of the electrochemical deposition reaction in Example 8 is 5 mA / cm 2 , the reaction time is 1h.

[0086] Embodiment 9:

[0087] A Raney nickel electrode is prepared in the same manner as in Example 1, except that the reaction time of the electrochemical deposition reaction in Example 9 is 1 hour, and the treatment temperature of the heat treatment is 500°C.

[0088] Embodiment 10:

[0089] A Raney nickel electrode, the preparation method is basically the same as that of Example 1, except that: the treatment temperature of the heat treatment in Example 10 is 300° C., and the treatment time is 2 hours.

[0090] Comparative Example 1:

[0091] A Raney nickel electrode, the preparation method comprising:

[0092] The same nickel mesh as in Example 1 was selected, and Ni 70 Al 30 Nickel-coated aluminum powder was used as the coating, and a plasma thermal spraying method was adopted, with a plasma arc power of 40kW, nitrogen powder feeding, a nozzle diameter of 0.8mm, a spraying distance of 120mm, a spraying angle of about 50°, and a gas pressure of 0.5MPa to prepare a nickel-aluminum coating with a thickness of 20 to 40μm on a nickel mesh;

[0093] The nickel mesh was placed in the same activation solution as in Example 1 for activation until no bubbles were precipitated, thereby obtaining a Raney nickel electrode.

[0094] Comparative Example 2:

[0095] A Raney nickel electrode, the preparation method is basically the same as that of Comparative Example 1, except that the nickel-coated aluminum powder used is Ni 80 Al 20 .

[0096] Comparative Example 3:

[0097] A Raney nickel electrode, the preparation method is basically the same as that of Comparative Example 1, except that: the plasma arc power of thermal spraying is 80Kw.

[0098] Comparative Example 4:

[0099] A Raney nickel electrode, the preparation method is basically the same as that of comparative example 1, except that: the spraying distance of thermal spraying is 150 mm.

[0100] Comparative Example 5:

[0101] A Raney nickel electrode, the preparation method is basically the same as that of comparative example 1, except that: the gas pressure of thermal spraying is 0.7 MPa.

[0102] Effect example 1:

[0103] The Raney nickel electrode prepared in Example 1 was characterized and analyzed to obtain Figure 2 , Figure 2 This is a SEM image of the Raney nickel electrode prepared in Example 1 of the present application.

[0104] like Figure 2 As shown, the surface of the Raney nickel electrode prepared in Example 1 exhibits a uniform pore structure. This is mainly because the present application deposits a nickel-zinc alloy phase on a nickel substrate. Since the nickel-zinc alloy reacts slowly and evenly during the activation process, the nickel-zinc crystal nuclei can nucleate and grow evenly, forming a uniform pore structure after activation.

[0105] The uniform pore structure greatly increases the surface catalytic active area of ​​the Raney nickel electrode, thereby significantly increasing the hydrogen reaction rate when applied to alkaline water electrolysis reactions.

[0106] Effect Example 2:

[0107] The LSV curves of the Raney nickel electrodes prepared in Examples 1 to 10 and Comparative Examples 1 to 5 were tested in a 30 wt % KOH solution at 80 ° C using a Bio-Logic electrochemical workstation and a saturated calomel reference electrode, and the current density was calculated to be 500 mA / cm 2The overpotential under the conditions was calculated by changing the scanning rate to calculate the double-layer capacitance of the Raney nickel electrode and the light nickel mesh, and the following data were obtained: Figure 3 and Figure 4 , Figure 3 is the LSV curve of Examples 1 to 3 of the present application and Comparative Example 1, Figure 4 It is the double-layer capacitance curve of Example 1, Comparative Example 1 and the bare nickel mesh.

[0108]

[0109]

[0110] As shown in the above table, Figure 3 As shown, the overpotentials of Examples 1 to 10 are significantly lower than those of Comparative Examples 1 to 5, wherein the Raney nickel electrode of Example 1 is 2 The overpotential at a current density of 240 mV is much lower than 332 mV of the thermal sprayed Raney nickel electrode in Comparative Example 1.

[0111] The electrochemically active area (ECSA) is proportional to the double layer capacitance, as shown in the above table and Figure 4 As shown, the double-layer capacitance values ​​of Examples 1 to 10 are all higher than those of Comparative Examples 1 to 5, wherein the double-layer capacitance value of Example 1 is 13.21 μF / cm 2 The double layer capacitance of comparative example 1 is 7.91 μF / cm 2 The double layer capacitance of the light nickel mesh is 0.24μF / cm 2 , it is calculated that the ECSA of Example 1 is 55 times that of the bare nickel mesh, and the ECSA of Example 1 is 1.67 times that of Comparative Example 1.

[0112] From the above data, it can be seen that the Raney nickel electrode of the present application has a higher active area and stronger catalytic performance than the traditional thermal sprayed Raney nickel electrode, which can help reduce the overpotential of the alkaline water electrolysis reaction and increase the hydrogen reaction rate. In addition, the raw material cost of the Raney nickel electrode of the present application is low, it is easy to use commercially, and has good prospects in the alkaline water hydrogen production industry.

[0113] It is obvious to those skilled in the art that the present application is not limited to the details of the exemplary embodiments described above, and that the present application can be implemented in other specific forms without departing from the spirit or essential features of the present application. Therefore, the embodiments should be regarded as exemplary and non-limiting in all respects, and the scope of the present application is defined by the appended claims rather than the above description, and it is intended that all changes falling within the meaning and scope of the equivalent elements of the claims be included in the present application. Any reference numeral in a claim should not be regarded as limiting the claim to which it relates.

[0114] In addition, it should be understood that although the present specification is described according to implementation modes, not every implementation mode contains only one independent technical solution. This description of the specification is only for the sake of clarity. Those skilled in the art should regard the specification as a whole. The technical solutions in each embodiment may also be appropriately combined to form other implementation modes that can be understood by those skilled in the art.

Claims

1. A method for preparing a Raney nickel electrode by electrodeposition of a nickel-zinc alloy, characterized in that: include: Pre-treating the nickel-based substrate; Using the pretreated nickel-based substrate as a cathode, and performing an electrochemical deposition reaction in an electrolytic cell filled with an electroplating solution, wherein the electroplating solution includes a nickel salt and a zinc salt; heat treating the electrochemically deposited nickel-based substrate; The heat-treated nickel-based substrate is activated to remove the zinc element and obtain a Raney nickel electrode.

2. The method according to claim 1, characterized in that The solvent of the electroplating solution is water, the solute is composed of nickel salt, zinc salt, boric acid and ammonium chloride, and the pH value of the electroplating solution is 4-6.

3. The method according to claim 2, characterized in that The concentration of the nickel salt is 50-150 g / L, the concentration of the zinc salt is 1-10 g / L, the concentration of the boric acid is 10-50 g / L, and the concentration of the ammonium chloride is 10-100 g / L.

4. The method according to claim 1, characterized in that: The nickel salt is nickel sulfate, and the zinc salt is zinc chloride.

5. The method according to claim 1, characterized in that The step of pre-treating the nickel-based substrate comprises: The nickel-based substrate is subjected to sandblasting treatment, and then a surfactant is added to perform ultrasonic treatment; The ultrasonically treated nickel-based substrate was immersed in acid.

6. The method according to claim 1, characterized in that The nickel-based substrate is a nickel mesh, and in the electrochemical deposition reaction, the anode includes two nickel-based stretched meshes with the same area as the nickel mesh, the two nickel-based stretched meshes are symmetrically arranged on both sides of the nickel mesh, and the nickel mesh is located on the connecting line of the two nickel-based stretched meshes; and / or, The electrochemical deposition reaction adopts a constant current with a current density of 5 to 20 mA / cm 2 The reaction time is 1 to 2 hours and the reaction temperature is room temperature.

7. The method according to claim 1, characterized in that The heat treatment temperature is 250-500° C. and the time is 1-2 hours.

8. The method according to claim 1, characterized in that The step of activating the heat-treated nickel-based substrate is specifically as follows: immersing the nickel-based substrate in an activation solution until no bubbles are precipitated; Wherein, the activation solution comprises sodium hydroxide solution and additives, the additives account for 5-15wt% of the activation solution, and the additives include the following components in parts by weight: 10-50 parts of organic solvent, 2-8 parts of Triton 100, 5-10 parts of sodium myristate and 7-15 parts of sodium citrate.

9. A Raney nickel electrode prepared by the method according to any one of claims 1 to 8.

10. Use of the Raney nickel electrode according to claim 9 as a hydrogen evolution electrode in an alkaline water electrolysis reaction.

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