A non-precious metal hydrogen evolution electrode and a preparation method thereof

Abstract

The invention discloses a non-precious metal hydrogen evolution electrode and a preparation method thereof, which comprises the following steps: S1, preparing a nickel electroplating solution, placing a copper substrate in the electroplating solution, and forming a nickel plating layer on the surface of the copper substrate by a direct current power supply electrodeposition method; S2, after the nickel plating is completed, washing and drying, and then placing in an activation solution for activation to obtain a non-precious metal hydrogen evolution electrode. The non-precious metal hydrogen evolution electrode can generate a nickel micro / nano composite structure on the surface of the copper substrate material to improve the hydrogen evolution catalytic performance.

Description

Technical Field

[0001] The invention relates to the preparation of a hydrogen evolution electrode, and in particular to a non-noble metal hydrogen evolution electrode and a preparation method thereof. Background Art

[0002] Energy and environmental issues have always been a hot topic of concern and research. With the shortage of non-renewable energy such as coal, oil and natural gas, people are in urgent need of finding new renewable energy to meet the needs of production and life. As a new energy source, hydrogen energy has the characteristics of high energy storage density, greenness and environmental friendliness. Its carbon reduction effect under the "dual carbon" goal has attracted much attention. In order to better play the role of hydrogen energy in carbon reduction and reduce the proportion of hydrogen production from natural gas and coal, the green production of hydrogen energy needs further research and optimization. The current green hydrogen production methods include alkaline water electrolysis, pyrolysis, microbial hydrogen production and photoenergy hydrogen production. Among them, alkaline water electrolysis is relatively mature, and the process is simple and the cost is low, so it can be applied to large-scale hydrogen production.

[0003] The important components of alkaline water electrolysis hydrogen production equipment are cathode, anode and electrolyte. Cathode is the key to hydrogen production, and its efficiency and cost determine the efficiency and cost of hydrogen production. At present, the preparation methods of hydrogen evolution electrodes include: hydrothermal method, physical vapor deposition, chemical vapor deposition and magnetron sputtering. The electrodeposition process is simple and low in cost. Compared with platinum, a metal with good hydrogen evolution performance, nickel has the advantages of abundant storage, low cost and good stability. Therefore, the preparation of nickel micro / nano composite structure hydrogen evolution electrode by electrodeposition has certain research significance. Summary of the invention

[0004] The object of the present invention is to provide a non-precious metal hydrogen evolution electrode and a preparation method thereof, which can generate a nickel micro / nano composite structure on the surface of a copper matrix material to improve the hydrogen evolution catalytic performance.

[0005] The method for preparing the non-precious metal hydrogen evolution electrode of the present invention comprises the following steps:

[0006] S1, preparing a nickel electroplating solution, placing a copper substrate in the electroplating solution, and forming a nickel plating layer on the surface of the copper substrate by a direct current power supply electrodeposition method;

[0007] S2, after the nickel plating is completed, it is cleaned, dried, and then placed in an activation solution for activation to obtain a non-precious metal hydrogen evolution electrode.

[0008] Furthermore, the activation solution in S2 is sodium fluorosilicate with a concentration of 0.03%-0.05%, and the activation time is 30-90 minutes.

[0009] Furthermore, the electroplating solution in S1 includes: 0.8-1.2 mol / L NiCl2·6H2O, 0.2-0.6 mol / L H3BO3, and 1.1-1.5 mol / L EDA·2HCl. EDA is the English abbreviation of "ethylenediamine".

[0010] Furthermore, the copper substrate in S1 is placed in the electroplating solution and is heated at 1.2~1.6A / dm 2 Nickel plating is carried out at a current density of , the nickel plating temperature is 58~65℃, the nickel plating time is 500~800s, and the pH value of the plating solution is 3.6~4.0.

[0011] Furthermore, the copper substrate described in S1 is pretreated before being placed in the electroplating solution, specifically: the surface of the copper substrate is polished with sandpaper, then ultrasonically cleaned with anhydrous ethanol, then pickled with acid, rinsed with deionized water, and blown dry for standby use.

[0012] A non-precious metal hydrogen evolution electrode is prepared by adopting the preparation method of the non-precious metal hydrogen evolution electrode of the present invention.

[0013] Compared with the prior art, the present invention has the following beneficial effects:

[0014] 1. The present invention forms a nickel coating on the surface of the copper substrate by nickel plating, and then obtains a non-precious metal hydrogen evolution electrode through an activation process, thereby ensuring that a dense and uniform coating is generated on the surface of the substrate. The coating is a nickel micro / nano composite structure and has good hydrogen evolution catalytic performance.

[0015] 2. The present invention adopts a direct current power supply electrodeposition method to prepare a nickel micro / nano composite structure coating on the surface of a copper substrate, which is simple to operate, has low equipment requirements, low cost, convenient plating solution preparation, less environmental harm, and meets environmental protection requirements. Moreover, the generated coating is dense and has a strong bonding force with the substrate, and there is basically no change in size. Through simple operation, a nickel micro / nano composite structure hydrogen evolution electrode with good hydrogen evolution performance is obtained. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 It is the polarization curve diagram of the material obtained after different activation times;

[0017] Figure 2 It is the impedance diagram of the material obtained after different activation times;

[0018] Figure 3 The non-precious metal hydrogen evolution electrode prepared in Example 1 is 2 Chronopotentiograph below;

[0019] Figure 4This is a polarization curve diagram of the non-precious metal hydrogen evolution electrode prepared in Example 1 before and after stabilization for 12 hours;

[0020] Figure 5 This is one of the microscopic morphology schematic diagrams of the non-precious metal hydrogen evolution electrode prepared in Example 1, with a magnification of 10.0K;

[0021] Figure 6 This is the second schematic diagram of the microscopic morphology of the non-precious metal hydrogen evolution electrode prepared in Example 1, with a magnification of 20.0K;

[0022] Figure 7 This is the third schematic diagram of the microscopic morphology of the non-precious metal hydrogen evolution electrode prepared in Example 1, with a magnification of 50.0K. DETAILED DESCRIPTION

[0023] In order to make the purpose, technical solution and advantages of the present invention clearer, the technical solution in the embodiment of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiment of the present invention. Obviously, the described embodiment is only a part of the embodiment of the present invention, not all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the present invention.

[0024] Embodiment 1, a method for preparing a non-precious metal hydrogen evolution electrode, comprising the following steps:

[0025] S1, preparing a nickel electroplating solution, wherein the electroplating solution includes 1.0 mol / L NiCl2·6H2O, 0.5 mol / L H3BO3, and 1.5 mol / L LEDA·2HCl.

[0026] The surface of the copper substrate was polished with sandpaper, then ultrasonically cleaned with anhydrous ethanol, and then pickled with acid, rinsed with deionized water, and dried for later use.

[0027] The copper substrate is placed in the prepared electroplating solution, and a nickel coating is formed on the surface of the copper substrate using a DC power supply electrodeposition method. The specific electroplating process parameters are: current density is 1.4A / dm 2 , the nickel plating temperature is 60°C, the nickel plating time is 650s, and the pH value of the plating solution is 3.8.

[0028] S2, after nickel plating is completed, it is cleaned and dried, and then immersed in an activation solution for activation. The activation solution used is a sodium fluorosilicate solution with a concentration of 0.04%. The immersion activation time is 60 minutes to obtain a non-precious metal hydrogen evolution electrode.

[0029] The morphology of the non-precious metal hydrogen evolution electrode prepared after activation was observed using a scanning electron microscope. Figures 5 to 7The nickel coating on the surface of the hydrogen evolution electrode presents a micro / nano cone-shaped structure and is evenly distributed.

[0030] Example 2, a method for preparing a non-precious metal hydrogen evolution electrode, wherein the immersion activation time is 30 minutes, and the rest is the same as that of Example 1.

[0031] Example 3, a method for preparing a non-precious metal hydrogen evolution electrode, wherein the immersion activation time is 90 min, and the rest is the same as that of Example 1.

[0032] The hydrogen evolution performance was characterized using the Netherlands Ivy portable electrochemical workstation and the cathode polarization curve was tested. The specific results are shown in Figure 1 and Figure 4 , the scanning rate is 1 mV / s, and the cathode polarization curve has been compensated for the voltage drop with a compensation percentage of 95%; Figure 1 It is the LSV curve under different activation times, which is used to characterize the electrocatalytic behavior of the electrode. At a constant current density, the lower the overpotential, the better the catalytic ability. Figure 1 As shown in the figure, after 60 min activation, the hydrogen evolution electrode is at -10 mA / cm 2 and -100 mA / cm 2 The overpotentials under these conditions are all low, indicating that they have the best catalytic ability. Figure 4 It is the LSV curve before and after constant potential for 12 hours, indicating that after 12 hours of stability test, its hydrogen evolution performance decreased slightly, but it still has good hydrogen evolution performance.

[0033] Test impedance spectrum, see the specific results Figure 2 , the test frequency interval is 10 5 ~10 -2 Hz, and the disturbance signal is 10 mV. Figure 2 The impedance Nyquist plot at different activation times is used to further study the kinetics and mechanism of catalysis. In the Nyquist plot at constant potential, the charge transfer resistance R ct The smaller it is, the better its hydrogen evolution performance is. Figure 2 As shown in Figure 2, the charge transfer resistance of the electrode activated for 60 min is the smallest, indicating that its kinetics has increased. Figure 1 The LSV curve in is consistent.

[0034] Chronopotentiometry stability test, see the specific results Figure 3 , the test current density is -100 mA / cm 2 , time is 12h, Figure 3 is at -100 mA / cm 2The chronopotentiometry under current density is used to characterize the electrocatalytic durability of the electrode. In addition to the catalytic activity, the catalytic stability of the electrode is also important. 2 The change of its potential is detected under the current density of , and the smaller the potential change is, the better its stability is. Figure 3 As shown, there is no obvious change in potential after 12 h, indicating its good stability.

Claims

1. A method for preparing a non-precious metal hydrogen evolution electrode, characterized in that: The steps include: S1, preparing a nickel electroplating solution, placing a copper substrate in the electroplating solution, and forming a nickel plating layer on the surface of the copper substrate by a direct current power supply electrodeposition method; the electroplating solution comprises: 0.8-1.2 mol / L NiCl2·6H2O, 0.2-0.6 mol / L H3BO3, and 1.1-1.5 mol / L EDA·2HCl; S2, after nickel plating is completed, it is cleaned and dried, and then placed in an activation solution for activation to obtain a non-precious metal hydrogen evolution electrode; the activation solution is: sodium fluorosilicate with a concentration of 0.03%-0.05%, and the activation time is 30~90min.

2. The method for preparing a non-precious metal hydrogen evolution electrode according to claim 1, characterized in that: In S1, the copper substrate is placed in the electroplating solution and heated at 1.2~1.6A / dm 2 Nickel plating is carried out at a current density of , the nickel plating temperature is 58~65℃, the nickel plating time is 500~800s, and the pH value of the plating solution is 3.6~4.

0.

3. The method for preparing a non-precious metal hydrogen evolution electrode according to claim 1 or 2, characterized in that: The copper substrate described in S1 is pretreated before being placed in the electroplating solution, specifically: the surface of the copper substrate is polished with sandpaper, then ultrasonically cleaned with anhydrous ethanol, then pickled with acid, rinsed with deionized water, and blown dry for standby use.

4. A non-precious metal hydrogen evolution electrode, characterized in that: The non-precious metal hydrogen evolution electrode is prepared by the preparation method of any one of claims 1 to 3.

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