Silicon dioxide / cobalt-nickel self-supporting hydrogen evolution electrocatalyst and preparation method thereof

Abstract

The invention discloses a silicon dioxide / cobalt-nickel self-supporting hydrogen evolution electrocatalyst and a preparation method thereof.The preparation method comprises the steps that foamed nickel is subjected to cleaning and drying pretreatment, and pretreated foamed nickel is obtained; synthesizing a CoNi LDH-coated NF precursor material by using the pretreated foamed nickel and adopting a hydrothermal method; and electroplating SiO2 on the CoNi LDH-coated NF precursor material by adopting an electrochemical induction process to obtain the SiO2 / CoNi LDH-coated NF self-supporting catalyst. The problems that a traditional powder coating type material is low in activity and poor in stability are solved, the preparation process is simple, and the prepared silicon dioxide / cobalt-nickel self-supporting electrocatalyst is good in electrocatalytic performance, good in stability and low in cost.

Description

Technical Field

[0001] The invention belongs to the technical field of catalysts, and in particular relates to a silicon dioxide / cobalt nickel self-supporting hydrogen evolution electrocatalyst and a preparation method thereof. Background Art

[0002] Energy crisis and environmental pollution are becoming increasingly serious, and the development of sustainable and clean energy is urgent. Hydrogen is a clean, sustainable, zero-carbon emission energy source, and is widely regarded as an alternative to traditional fossil fuels. High-purity hydrogen can be produced on a large scale by electrolysis of water. The electrolysis of water can use intermittent solar energy and wind energy as the energy to start the reaction, and obtain high-purity hydrogen for industrial fields such as fuel cells. However, one of the half reactions of water electrolysis, the hydrogen evolution reaction (HER) at the cathode, reacts slowly in electrochemical kinetics. Therefore, in order to reduce the catalytic reaction energy barrier and increase the reaction rate, it is necessary to develop new electrocatalysts with high efficiency and high stability. Precious metal materials are considered to be the most advanced electrocatalysts for HER due to their high intrinsic catalytic activity, but their large-scale use is seriously hindered by factors such as their low element content, high price and low stability. Therefore, there is an urgent need to develop low-cost, highly stable and highly catalytically active water electrolysis catalysts.

[0003] Research has found that nickel foam (NF) is an excellent current collector commonly used in energy conversion, with a stable 3D grid structure and good conductivity. By directly growing self-supporting active materials on NF, the contact between the active materials and the electrolyte can be promoted, more active sites can be exposed, mass transfer can be enhanced, and the point catalytic performance can be improved. However, the regulation of its stability and morphology is still a key issue that needs to be solved. Therefore, designing and preparing self-supporting electrocatalyst materials with high activity, high stability and corrosion resistance is an effective method to deal with water electrolysis. Summary of the invention

[0004] In order to solve the above problems existing in the prior art, the present invention provides a silicon dioxide / cobalt nickel self-supporting hydrogen evolution electrocatalyst and a preparation method thereof. The technical problem to be solved by the present invention is achieved by the following technical solution:

[0005] The present invention provides a method for preparing a silicon dioxide / cobalt nickel self-supporting hydrogen evolution electrocatalyst, comprising:

[0006] S1: performing cleaning and drying pretreatment on the nickel foam to obtain the pretreated nickel foam;

[0007] S2: Using the pretreated nickel foam, the CoNi LDH@NF precursor material was synthesized by hydrothermal method;

[0008] S3: electroplating SiO2 on the CoNi LDH@NF precursor material using an electrochemical induction process to obtain a SiO2 / CoNi LDH@NF self-supporting catalyst.

[0009] In one embodiment of the present invention, the S1 includes:

[0010] The prepared nickel foam is cut into a preset size, and ultrasonically washed with acetone, hydrochloric acid with a preset concentration, anhydrous ethanol and deionized water for 10 to 30 minutes respectively, and rinsed with deionized water several times in between each washing;

[0011] The washed nickel foam is placed in a vacuum drying oven and dried at 60-80°C until completely dry.

[0012] In one embodiment of the present invention, the concentration of the hydrochloric acid is 6-8 Mol / L.

[0013] In one embodiment of the present invention, the S2 includes:

[0014] S2.1: dissolving a preset amount of (NiNO3)2·6H2O, Co(NO3)2·6H2O and urotropine in a mixed solvent of anhydrous ethanol and deionized water, and stirring evenly to form a mixed solution;

[0015] S2.2: placing the pretreated nickel foam into a beaker containing the mixed solution to fully infiltrate it, and heating it in an oven at 60 to 100° C. for 6 to 12 hours to cause recrystallization, so that NiCo grows uniformly on the nickel foam;

[0016] S2.3: After the reaction is completed, the nickel foam with NiCo grown thereon is washed and dried multiple times to obtain the CoNiLDH@NF precursor material.

[0017] In one embodiment of the present invention, the mass ratio of the (NiNO3)2·6H2O, the Co(NO3)2·6H2O and the urotropine is (1-2):1:(1-2).

[0018] In one embodiment of the present invention, in a mixed solvent of anhydrous ethanol and deionized water, the volume ratio of the anhydrous ethanol to the deionized water is (2-4):1.

[0019] In one embodiment of the present invention, S3 includes:

[0020] Dissolving a predetermined amount of SiO2 and KOH in deionized water to obtain an electroplating solution;

[0021] The CoNi LDH@NF precursor material is used as an anode and a polished aluminum sheet is used as a cathode. An electroplating voltage is applied between the cathode and the anode. SiO2 is electroplated on the surface of the CoNi LDH@NF precursor material using the electroplating solution to form a SiO2 / CoNi LDH@NF self-supporting hydrogen evolution electrocatalyst.

[0022] In one embodiment of the present invention, the molar ratio of SiO2 to KOH in the electroplating solution is 1:(10-15).

[0023] In one embodiment of the present invention, the electroplating voltage is 0.5-0.8V.

[0024] Another aspect of the present invention provides a silicon dioxide / cobalt nickel self-supporting hydrogen evolution electrocatalyst, which is prepared using any preparation method described in any one of the above embodiments.

[0025] Compared with the prior art, the present invention has the following beneficial effects:

[0026] 1. The silicon dioxide / cobalt nickel self-supporting hydrogen evolution electrocatalyst and preparation method provided by the present invention overcome the problems of low activity and poor stability of traditional powder coating materials, and the preparation process is simple. The nickel foam not only provides a three-dimensional structure as a self-supporting matrix, increases the charge transfer rate, but also provides the nickel source required for the reaction. The elements (Co and Ni) are introduced into the nickel foam (NF) material for electrocatalytic hydrogen evolution by a hydrothermal method, and then the Si ion growth is electrochemically induced to further improve its electrochemical performance and stability. The prepared silicon dioxide / cobalt nickel self-supporting electrocatalyst material not only has good electrocatalytic performance, but also has good stability, and is relatively inexpensive relative to precious metal materials. It is a self-supporting catalyst preparation method that can be promoted. The present invention not only has a simple preparation process and strong scalability, but also can flexibly adjust the raw material ratio according to different needs to prepare a series of catalysts with different contents required.

[0027] 2. The silica / cobalt-nickel self-supporting hydrogen evolution electrocatalyst of the present invention exhibits efficient hydrogen evolution capability when used as a catalyst. In addition, the silica / cobalt-nickel self-supporting hydrogen evolution electrocatalyst prepared by the present invention not only has a large specific surface area and many electrochemically active sites, but also has excellent electrocatalytic performance under high current density.

[0028] 3. The present invention uses a simpler and safer hydrothermal method to synthesize a uniform precursor catalyst, and also uses a simple electrochemical induction process to select low-cost SiO2 materials to greatly improve the electrochemical performance of the material. The synergistic effect of multiple elements in the catalyst can adjust and optimize the electronic structure of the LDH cation layer and the catalytic activity of the active site, and reduce the thermodynamic energy barrier of HER.

[0029] The present invention will be further described in detail below with reference to the accompanying drawings and embodiments. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] Figure 1 It is a flow chart of a method for preparing a silicon dioxide / cobalt nickel self-supporting hydrogen evolution electrocatalyst provided by an embodiment of the present invention;

[0031] Figure 2 This is a scanning electron microscope image (SEM) of the silicon dioxide / cobalt nickel self-supporting hydrogen evolution electrocatalyst (SiO2 / CoNiLDH@NF) prepared in Example 6 of the present invention;

[0032] Figure 3 This is an X-ray diffraction spectrum analysis chart (XRD) of the silicon dioxide / cobalt nickel self-supporting hydrogen evolution electrocatalyst (SiO2 / CoNiLDH@NF) prepared in Example 6 of the present invention;

[0033] Figure 4 is a HER linear sweep voltammetric curve of the CoNi LDH@NF precursor material prepared in an embodiment of the present invention in a 1.0 mol / L potassium hydroxide electrolyte at a scan rate of 5 mV per second;

[0034] Figure 5 This is a linear sweep voltammogram of the HER of SiO2 / CoNi LDH@NF-5 in Example 6 of the present invention at a scan rate of 5 mV / s in a 1.0 mol / L potassium hydroxide electrolyte. DETAILED DESCRIPTION

[0035] In order to further illustrate the technical means and effects adopted by the present invention to achieve the predetermined invention purpose, a silicon dioxide / cobalt nickel self-supporting hydrogen evolution electrocatalyst and a preparation method thereof proposed in accordance with the present invention are described in detail below in conjunction with the accompanying drawings and specific implementation methods.

[0036] The above and other technical contents, features and effects of the present invention are clearly presented in the following detailed description of the specific implementation modes in conjunction with the accompanying drawings. Through the description of the specific implementation modes, the technical means and effects adopted by the present invention to achieve the predetermined purpose can be more deeply and specifically understood. However, the attached drawings are only for reference and explanation purposes and are not used to limit the technical solutions of the present invention.

[0037] It should be noted that, in this article, relational terms such as first and second, etc. are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Moreover, the terms "include", "comprise" or any other variants are intended to cover non-exclusive inclusion, so that an article or device including a series of elements includes not only those elements, but also other elements that are not explicitly listed. In the absence of more restrictions, the elements defined by the statement "including one..." do not exclude the existence of other identical elements in the article or device including the elements.

[0038] Embodiment 1

[0039] See also Figure 1 , Figure 1 1 is a flow chart of a method for preparing a silicon dioxide / cobalt nickel self-supporting hydrogen evolution electrocatalyst provided by an embodiment of the present invention. The preparation method specifically comprises the following steps:

[0040] S1: performing cleaning and drying pretreatment on the nickel foam to obtain the pretreated nickel foam.

[0041] Specifically, the commercial nickel foam is cut into the required preset size, and ultrasonically washed for 10 to 30 minutes using acetone, hydrochloric acid of preset concentration, anhydrous ethanol and deionized water respectively, and rinsed several times with deionized water in between each washing, and the concentration of hydrochloric acid is 6 to 8 Mol / L. Subsequently, the washed nickel foam is placed in a vacuum drying oven at 60 to 80°C and dried for 8 to 12 hours until it is completely dry.

[0042] S2: Using the pretreated nickel foam, the CoNi LDH@NF precursor material was synthesized by hydrothermal method.

[0043] S2 of this embodiment includes:

[0044] S2.1: Dissolve a preset amount of (NiNO3)2·6H2O, Co(NO3)2·6H2O and urotropine in a mixed solvent of anhydrous ethanol and deionized water, and stir evenly to form a mixed solution. In this embodiment, the mass ratio of (NiNO3)2·6H2O, Co(NO3)2·6H2O and urotropine is (1-2):1:(1-2), and in the mixed solvent of anhydrous ethanol and deionized water, the volume ratio of anhydrous ethanol to deionized water is (2-4):1.

[0045] S2.2: The pretreated nickel foam is placed in a beaker containing the mixed solution to fully infiltrate it, and heated in an oven at 60 to 100° C. for 6 to 12 hours to cause recrystallization, so that NiCo grows evenly on the nickel foam.

[0046] S2.3: After the reaction is completed, the nickel foam with NiCo grown thereon is washed several times and dried in an oven at 40-60° C. for 6 hours to obtain a CoNi LDH@NF precursor material.

[0047] S3: SiO2 was electroplated on the CoNi LDH@NF precursor material using an electrochemical induction process to obtain a SiO2 / CoNiLDH@NF self-supporting catalyst.

[0048] Specifically, a predetermined amount of SiO2 and KOH are dissolved in deionized water to obtain an electroplating solution; a CoNi LDH@NF precursor material is used as an anode, and a polished aluminum sheet is used as a cathode. An electroplating voltage is applied between the cathode and the anode, and SiO2 is electroplated on the surface of the CoNi LDH@NF precursor material using the electroplating solution to form a SiO2 / CoNi LDH@NF self-supporting hydrogen evolution electrocatalyst.

[0049] In this embodiment, the molar ratio of SiO2 to KOH in the electroplating solution is 1:(10-15), the electroplating voltage is 0.5-0.8V, and the electroplating time can be 5-120min.

[0050] Another embodiment of the present invention further provides a silicon dioxide / cobalt nickel self-supporting hydrogen evolution electrocatalyst, which is prepared using the above preparation method.

[0051] The preparation method adopted by the present invention is simple and easy to operate, and a water electrolysis catalyst with high efficiency, low cost and good stability can be prepared by a hydrothermal method.

[0052] Embodiment 2

[0053] Based on Example 1, this example provides a specific preparation method of a silicon dioxide / cobalt nickel self-supporting hydrogen evolution electrocatalyst, and the chemical expression of the prepared silicon dioxide / cobalt nickel self-supporting hydrogen evolution electrocatalyst is SiO2 / CoNiLDH@NF-1. The specific preparation method includes:

[0054] Step 1: Pretreatment of nickel foam: Cut the purchased commercial nickel foam into the required size, and ultrasonically wash it with acetone, 6Mol / L dilute hydrochloric acid, anhydrous ethanol and deionized water for 10 to 30 minutes respectively in order. Rinse it with deionized water several times in between each washing. Finally, put the washed nickel foam into a vacuum drying oven at 60 to 80°C and dry it for 8 to 12 hours until it is completely dry.

[0055] Step 2: Synthesize the precursor CoNi LDH@NF material by hydrothermal method: Dissolve 8-10g (NiNO3)2·6H2O, 4-6g Co(NO3)2·6H2O and 5g urotropine in a mixed solvent of 150mL anhydrous ethanol and 50mL deionized water, and stir to mix them evenly to form a mixed solution. Subsequently, the pretreated nickel foam is placed in a beaker containing the mixed solution to fully soak it, and heated in an oven at 90°C for 6-12 hours to recrystallize, so that NiCo grows evenly on the nickel foam. After the reaction is completed, the nickel foam with NiCo is washed several times with deionized water, and then dried in an oven at 40-60°C for 6 hours to obtain the CoNi LDH@NF precursor material.

[0056] Step 3: Use electrochemical induced plating of SiO2 to obtain a SiO2 / CoNi LDH@NF self-supporting catalyst: Dissolve SiO2 powder and flake KOH in deionized water to obtain a plating solution, wherein the plating solution contains 0.001-0.003Mol / L of SiO2 and 0.001-0.003Mol / L of KOH. Use the CoNi LDH@NF precursor material as the anode and the polished aluminum sheet as the cathode. Apply a plating voltage between the cathode and the anode, and use the plating solution to electroplate SiO2 on the surface of the CoNi LDH@NF precursor material to form a SiO2 / CoNi LDH@NF self-supporting hydrogen evolution electrocatalyst. Set the plating voltage to 0.6-0.8V and the plating time to 5min to prepare the SiO2 / CoNi@NF-1 self-supporting catalyst electrode.

[0057] Embodiment 3

[0058] On the basis of Example 2, this example provides another specific preparation method of a silica / cobalt nickel self-supporting hydrogen evolution electrocatalyst. The only difference between this preparation method and the preparation method of Example 2 is that the electroplating time is 20 min, and the chemical expression of the prepared silica / cobalt nickel self-supporting hydrogen evolution electrocatalyst is SiO2 / CoNi LDH@NF-2.

[0059] Embodiment 4

[0060] On the basis of Example 2, this example provides another specific preparation method of a silica / cobalt nickel self-supporting hydrogen evolution electrocatalyst. The only difference between this preparation method and the preparation method of Example 2 is that the electroplating time is 30 min, and the chemical expression of the prepared silica / cobalt nickel self-supporting hydrogen evolution electrocatalyst is SiO2 / CoNi LDH@NF-3.

[0061] Embodiment 5

[0062] On the basis of Example 2, this example provides another specific preparation method of a silica / cobalt nickel self-supporting hydrogen evolution electrocatalyst. The only difference between this preparation method and the preparation method of Example 2 is that the electroplating time is 45 min, and the chemical expression of the prepared silica / cobalt nickel self-supporting hydrogen evolution electrocatalyst is SiO2 / CoNi LDH@NF-4.

[0063] Embodiment 6

[0064] On the basis of Example 2, this example provides another specific preparation method of a silica / cobalt nickel self-supporting hydrogen evolution electrocatalyst. The only difference between this preparation method and the preparation method of Example 2 is that the electroplating time is 60 min, and the chemical expression of the prepared silica / cobalt nickel self-supporting hydrogen evolution electrocatalyst is SiO2 / CoNi LDH@NF-5.

[0065] See also Figure 2 and Figure 3 , Figure 2 This is a scanning electron microscope image (SEM) of the silicon dioxide / cobalt nickel self-supporting hydrogen evolution electrocatalyst (SiO2 / CoNi LDH@NF) prepared in Example 6 of the present invention; Figure 3 is an X-ray diffraction spectrum analysis diagram (XRD) of the silicon dioxide / cobalt nickel self-supporting hydrogen evolution electrocatalyst (SiO2 / CoNi LDH@NF) prepared in Example 6 of the present invention. Figure 2 It can be seen that a large number of nanosheets were synthesized and covered the surface of nickel foam, exposing more active sites. Figure 3 It can be seen that after hydrothermal treatment, the hydroxyl oxidation peaks of Co and Ni appeared in CoNi LDH@NF. With the introduction of Si, the peaks gradually became flat, and the original hydroxyl oxidation peaks were no longer obvious.

[0066] When the silicon dioxide / cobalt nickel self-supporting hydrogen evolution electrocatalyst (SiO2 / CoNi LDH@NF) prepared in the embodiment of the present invention is used as a catalyst, the specific steps are as follows: the prepared SiO2 / CoNi@NF self-supporting catalyst is clamped on a platinum electrode clamp as a working electrode, a mercury oxide electrode is used as a reference electrode, and a carbon rod is used as a counter electrode. The electrochemical performance of HER is tested in a 1Mol / L KOH solution at room temperature and pressure.

[0067] See also Figure 4 and Figure 5 , Figure 4 HER linear sweep voltammogram of the CoNi LDH@NF precursor material prepared in the embodiment of the present invention (before Si electroplating) in a 1.0 mol / L potassium hydroxide electrolyte at a scan rate of 5 mV / s; Figure 5This is a linear sweep voltammogram of the HER of SiO2 / CoNi LDH@NF-5 (after Si electroplating) in Example 6 of the present invention at a scan rate of 5 mV / s in a 1.0 mol / L potassium hydroxide electrolyte.

[0068] The electrochemical performance of HER of CoNi LDH@NF precursor material and SiO2 / CoNiLDH@NF-5 was tested in 1Mol / L KOH solution at room temperature and pressure. Figure 5 As shown, at 10 mA cm -2 At a current density of 1.3 Å, the HER overpotential of SiO2 / CoNi LDH@NF-5 is 96 mV, which is significantly higher than that of the CoNi LDH@NF precursor material before electroplating (such as Figure 4 As shown, the overpotential is 206 mV), and the electrochemical performance has been greatly improved.

[0069] In summary, the silicon dioxide / cobalt nickel self-supporting hydrogen evolution electrocatalyst and preparation method provided by the present invention overcome the problems of low activity and poor stability of traditional powder coating materials, and the preparation process is simple. The nickel foam not only provides a three-dimensional structure as a self-supporting matrix, increases the charge transfer rate, but also provides the nickel source required for the reaction. The elements (Co and Ni) are introduced into the nickel foam (NF) material for electrocatalytic hydrogen evolution by a hydrothermal method, and then the Si ion growth is electrochemically induced to further improve its electrochemical performance and stability. The prepared silicon dioxide / cobalt nickel self-supporting electrocatalyst material not only has good electrocatalytic performance, but also has good stability, and is relatively inexpensive relative to precious metal materials. It is a self-supporting catalyst preparation method that can be promoted. The present invention not only has a simple preparation process and strong scalability, but also can flexibly adjust the raw material ratio according to different needs to prepare a series of catalysts with different contents required.

[0070] The silica / cobalt-nickel self-supporting hydrogen evolution electrocatalyst of the present invention exhibits efficient hydrogen evolution capability when used as a catalyst. In addition, the silica / cobalt-nickel self-supporting hydrogen evolution electrocatalyst prepared by the present invention not only has a large specific surface area, but also has many electrochemically active sites and excellent electrocatalytic performance under high current density. The present invention utilizes a simpler and safer hydrothermal method to synthesize a uniform precursor catalyst, and also utilizes a simple electrochemical induction process to select low-cost SiO2 materials, thereby greatly improving the electrochemical performance of the material. The synergistic effect of multiple elements in the catalyst can adjust and optimize the electronic structure of the LDH cation layer and the catalytic activity of the active sites, thereby reducing the thermodynamic energy barrier of HER.

[0071] In the several embodiments provided by the present invention, it should be understood that the apparatus and method disclosed by the present invention can be implemented in other ways. For example, the apparatus embodiments described above are only illustrative, for example, the division of the modules is only a logical function division, and there may be other division methods in actual implementation, for example, multiple modules or components can be combined or integrated into another system, or some features can be ignored or not executed.

[0072] In addition, each functional module in each embodiment of the present invention may be integrated into one processing module, or each module may exist physically separately, or two or more modules may be integrated into one module. The above-mentioned integrated module may be implemented in the form of hardware or in the form of hardware plus software functional modules.

[0073] The above contents are further detailed descriptions of the present invention in combination with specific preferred embodiments, and it cannot be determined that the specific implementation of the present invention is limited to these descriptions. For ordinary technicians in the technical field to which the present invention belongs, several simple deductions or substitutions can be made without departing from the concept of the present invention, which should be regarded as falling within the protection scope of the present invention.

Claims

1. A method for preparing a silicon dioxide / cobalt nickel self-supporting hydrogen evolution electrocatalyst, characterized in that: include: S1: cleaning and drying the nickel foam to obtain the pretreated nickel foam; S2: Using the pretreated nickel foam, the CoNi LDH@NF precursor material was synthesized by hydrothermal method; S3: electroplating SiO2 on the CoNiLDH@NF precursor material using an electrochemical induction process to obtain a SiO2 / CoNiLDH@NF self-supporting catalyst.

2. The method for preparing the silicon dioxide / cobalt nickel self-supporting hydrogen evolution electrocatalyst according to claim 1, characterized in that: The S1 includes: The prepared nickel foam is cut into a preset size, and ultrasonically washed with acetone, hydrochloric acid with a preset concentration, anhydrous ethanol and deionized water for 10 to 30 minutes respectively, and rinsed with deionized water several times in between each washing; The washed nickel foam is placed in a vacuum drying oven and dried at 60-80°C until completely dry.

3. The method for preparing the silicon dioxide / cobalt nickel self-supporting hydrogen evolution electrocatalyst according to claim 2, characterized in that: The concentration of the hydrochloric acid is 6-8Mol / L.

4. The method for preparing the silicon dioxide / cobalt nickel self-supporting hydrogen evolution electrocatalyst according to claim 1, characterized in that: The S2 includes: S2.1: dissolving a preset amount of (NiNO3)2·6H2O, Co(NO3)2·6H2O and urotropine in a mixed solvent of anhydrous ethanol and deionized water, and stirring evenly to form a mixed solution; S2.2: placing the pretreated nickel foam into a beaker containing the mixed solution to fully infiltrate it, and heating it in an oven at 60 to 100° C. for 6 to 12 hours to cause recrystallization, so that NiCo grows uniformly on the nickel foam; S2.3: After the reaction is completed, the nickel foam on which NiCo is grown is washed and dried multiple times to obtain the CoNi LDH@NF precursor material.

5. The method for preparing the silicon dioxide / cobalt nickel self-supporting hydrogen evolution electrocatalyst according to claim 4, characterized in that: The mass ratio of the (NiNO3)2·6H2O, the Co(NO3)2·6H2O and the urotropine is (1-2):1:(1-2).

6. The method for preparing the silicon dioxide / cobalt nickel self-supporting hydrogen evolution electrocatalyst according to claim 4, characterized in that: In the mixed solvent of anhydrous ethanol and deionized water, the volume ratio of the anhydrous ethanol to the deionized water is (2-4):

1.

7. The method for preparing the silicon dioxide / cobalt nickel self-supporting hydrogen evolution electrocatalyst according to claim 1, characterized in that: The S3 includes: Dissolving a predetermined amount of SiO2 and KOH in deionized water to obtain an electroplating solution; The CoNi LDH@NF precursor material is used as an anode and a polished aluminum sheet is used as a cathode. An electroplating voltage is applied between the cathode and the anode. SiO2 is electroplated on the surface of the CoNi LDH@NF precursor material using the electroplating solution to form a SiO2 / CoNiLDH@NF self-supporting hydrogen evolution electrocatalyst.

8. The method for preparing the silicon dioxide / cobalt nickel self-supporting hydrogen evolution electrocatalyst according to claim 7, characterized in that: The molar ratio of SiO2 to KOH in the electroplating solution is 1:(10-15).

9. The method for preparing the silicon dioxide / cobalt nickel self-supporting hydrogen evolution electrocatalyst according to claim 7, characterized in that: The electroplating voltage is 0.5-0.8V.

10. A silicon dioxide / cobalt nickel self-supporting hydrogen evolution electrocatalyst, characterized in that: The method is prepared by the method according to any one of claims 1 to 9.

Images