Copper-based electrode and preparation and application thereof

Abstract

The invention relates to a copper-based electrode and preparation and application thereof. The preparation method of the electrode comprises the following steps: pretreating the substrate, performing electrochemical etching reconstruction on the copper substrate through a constant voltage method under the condition of not adding an additional Cu source, growing a copper-cobalt transition metal oxide and boride catalyst, and performing high-temperature roasting to prepare the copper-based double-effect electrode. The structure shows excellent oxygen evolution and hydrogen evolution activity and stability in an alkaline medium. The (integrated) electrode prepared by the method does not depend on a current collector and an additional binder, so that the preparation process is simplified, and the cost is reduced. The electrode can be used for a water electrolysis hydrogen evolution electrode, a water electrolysis oxygen evolution electrode, a seawater electrolysis hydrogen evolution electrode, a seawater electrolysis oxygen evolution electrode, a metal air battery charging cathode and anode or an electrode in fuel cell reaction under an energy storage condition.

Description

TECHNICAL FIELD

[0001] The present application belongs to the field of electrolysis of water, and particularly relates to a copper-based electrode and preparation and application thereof. BACKGROUND

[0002] With the rapid development of economy, the demand for energy is increasing day by day, and the large consumption of fossil energy has intensified the greenhouse effect and caused serious damage to the global ecological environment. In order to effectively reduce the dependence on fossil energy, reduce pollution emissions, and curb the trend of environmental degradation, the development and promotion of renewable energy has become an inevitable strategic choice to achieve sustainable development and carbon emission reduction goals. However, the development and utilization of renewable energy such as wind and solar energy has the bottleneck problem of discontinuity and instability. In contrast, hydrogen energy has high calorific value, is clean and environmentally friendly, has a wide range of sources, diverse applications, and good storage and transportation characteristics. As an important part of future energy systems, hydrogen energy has great potential in the fields of transportation, industry, and power.

[0003] The technology of electrolysis of water to produce "green hydrogen" is one of the important ways to achieve carbon dioxide emission reduction and renewable energy storage. At present, the most excellent industrial-grade water electrolysis catalyst still relies on noble metal materials such as platinum (Pt), iridium oxide (IrO2), and ruthenium oxide (RuO2). However, the high cost of these catalysts limits their industrial application. Therefore, the development of non-noble metal water electrolysis catalysts has become an important development trend. Among them, the oxides formed by cobalt (Co) and copper (Cu) have attracted widespread attention due to their excellent electronic conductivity and low cost. The synergistic effect of multiple elements improves the hydrogen evolution (HER) and oxygen evolution (OER) activity of the catalyst, and also enhances its stability. Wang et al. [Nano Letters, 2017, 17(12): 7989-7994.] developed CuCo2O4 particles with OER activity, which showed a 327 mV overpotential at a current density of 10 mA cm -2 . The copper-cobalt oxide has strong stability, but its overpotential is still high. Zheng [European Journal of Inorganic Chemistry, 2018, (31): 3565-3569.] et al. pointed out that CuCo2O4 nanorod arrays have HER activity, with an overpotential of 227 mV at a current density of 20 mA cm -2 . However, these cobalt-copper-based composites and their derived transition metal oxide material-based electrodes cannot simultaneously maintain high catalytic activity and stability for HER and OER, and their catalytic activity and durability still need to be improved. Especially during the long-term electrolysis process, the catalysts are easily detached from the electrode surface, thereby reducing their catalytic activity.

[0004] In view of the above prior art problems, the purpose of the present application is to provide a Cu-based electrode and its preparation and application. The present application first uses a constant voltage method to electrochemically etch the substrate, grow more defect sites and active groups on its surface, and at the same time, grow nanoparticles on the surface of the etched substrate to increase the loading area, then uses a H3BO3 assisted hydrothermal calcination method to load metal oxides on the surface, and prepares a copper-based electrode B-Cu x Co y / Cu-E / T-CF, wherein the loading amount of copper cobalt oxide is 0.6 mg / cm 2 ~ 3.5 mg / cm 2 , the loading amount of copper cobalt boride is 0.1 mg / cm 2 ~ 1.5 mg / cm 2 .

[0005] The electrochemical etching of the substrate increases the loading area of the substrate, and at the same time, the defect sites and active groups (such as -OH) generated on the surface of the copper substrate can also enhance the bonding and ability of the catalyst with the substrate layer, so that it is not easy to fall off during the test process, and the stability of the catalyst is enhanced. In addition, after etching, the surface of the substrate grows B-Cu x Co y a large number of nanoparticles, so as to increase the loading area and increase the active sites, and by adjusting the intrinsic electronic structure of the active material, the stability and catalytic activity of the catalyst are improved. This preparation method coupling electrochemical etching reconstruction and chemical preparation technology makes the prepared electrode have high HER and OER dual functional activity and stability.

[0006] The electrode prepared by the present application does not need to add additional binder and current collector, which fundamentally optimizes the comprehensive performance of the electrode; its unique through-type three-dimensional structure can ensure that the electrolyte is fully infiltrated, and significantly promotes the transmission efficiency of the reactants and products. SUMMARY

[0007] A copper-based self-supporting electrode preparation and application, the electrode comprises a substrate, a copper cobalt oxide, a cobalt boride compound catalyst, the thickness of the substrate layer is 0.5-1.5mm; the copper cobalt oxide presents a nanowire structure, which is composed of CuO, Co3O4 and CuCo2O4, the length of the nanowire is 170 nm~350 nm, the diameter of the nanowire is 0.005 μm~2 μm, the loading amount of the copper cobalt oxide on the substrate is 0.1 mg / cm 2 ~5.5mg / cm 2 , the cobalt boride compound presents a nanoparticle structure, the diameter of the nanoparticle is 0.05 μm~2 μm, the cobalt boride compound is CoB, and the loading amount on the substrate is 0.1 mg / cm 21.5 mg / cm 2 , B-Cu x Co y The total loading amount of CuO produced by etching and copper cobalt oxide and cobalt boride after hydrothermal calcination in the Cu-E / T-CF electrode is 1 mg / cm 2 6.5 mg / cm 2 .

[0008] The preparation method of the three-dimensional porous electrode includes the following specific steps: S1: a copper substrate with a thickness of 0.5-1.5 mm and an area of 1.5-4.5 cm 2 is pressed on a tablet press at 0.3 MPa-3 MPa for 40-120 s (preferably 45-90 s), and then is ultrasonically treated in a 0.5 mol / L-3 mol / L (preferably 0.5 mol / L-1.5 mol / L) HCl solution for 10 min-40 min, is washed with acetone or anhydrous ethanol, and ultrapure water multiple times, and is placed in a vacuum oven at 30℃-90℃ (40℃-90℃) for drying and standby; S2: the treated copper substrate is electrochemically etched in an aqueous solution formed by one or both of KCl and NaCl by using a constant voltage method, denoted as Cu-E / T-CF, and is washed with an ultrapure solvent after etching; the volume of the KCl and / or NaCl aqueous solution is 150-250 mL; S3: copper salt, cobalt salt, boric acid, and a stabilizer are mixed into deionized water, and are magnetically stirred at room temperature for 20-60 min to form a precursor cobalt-copper mixed solution, the volume of the precursor cobalt-copper mixed solution is 30-80 mL, is poured into a reaction kettle, and then the pretreated Cu-E / T-CF is placed in the reaction kettle, and is placed in a vacuum oven for reaction. After the reaction is completed, the reaction kettle is taken out and cooled, and is washed with acetone or anhydrous ethanol, and ultrapure water multiple times, and is placed in a vacuum oven at 40℃-80℃ for drying for 6 h-15 h to obtain an electrode a; the molar ratio of the copper salt to the cobalt salt is 0.1-10; S4: the dried electrode a is placed in a muffle furnace for calcination in a nitrogen atmosphere to obtain a copper-based self-supporting electrode B-Cu x Co yThe molar percentage of B is 5-15%, the molar percentage of Cu is 15-55% (not including the copper substrate, only the copper content of the catalyst layer), the molar percentage of Co is 25-45%, and the molar percentage of O is 30-60%. The contents of B, Cu and Co in the hydrothermal process are measured by ICP, and the estimated statistical values are obtained by subtracting the content of the element in ICP from the added amount. The estimated value of O is obtained by analyzing and coordinating XPS, XRD and the like.

[0009] All electrodes in the experiment were tested in a three-electrode system of 1M KOH solution, with Hg / HgO as the reference electrode, a platinum sheet with a length x width of 1cm x 1cm as the counter electrode, and a catalyst electrode with a length x width of 1cm x 1cm as the working electrode. The distance between the working electrode and the counter electrode was 3cm-8cm. The potential range for hydrogen evolution test (HER) was-0.2V to-1.7V (vs. Hg / HgO), and the potential range for oxygen evolution test (OER) was 0.0V to 1.0V (vs. Hg / HgO). The scanning rate was 5mV s -1 .

[0010] The porosity of the substrate before pressing is 93-98%, and the porosity of the substrate after pressing is 80-90%.

[0011] In step S1, the ultrasonic treatment time is preferably 35min; and the drying temperature is preferably 70℃.

[0012] In step S1, the HCl concentration is 0.5mol / L-1.5mol / L, and the HCl concentration is preferably 0.8mol / L-1.2mol / L.

[0013] In step S2, the NaCl and / or KCl concentration is 0.5mol / L-2.0mol / L, and the concentration is preferably 1.0mol / L-1.5mol / L. In step S2, the constant voltage etching voltage range is-0.8V~0.7V, and the preferred voltage range is-0.3V~0.5V. The constant voltage etching time is 2min-30min, and the preferred time is 5min-20min.

[0014] In step S3, the cobalt salt solution is one or more of cobalt carbonate, cobalt sulfate, cobalt chloride, cobalt nitrate solution and cobalt acetate solution. The concentration of cobalt salt is 0.01mol / L-5.0mol / L, and the preferred concentration is 0.2mol / L-1.5mol / L. In step S3, the copper salt solution is one or more copper salts selected from copper sulfate, copper acetate, copper chloride, copper nitrate, copper phosphate, etc., and the concentration of the copper salt is 0.01 mol / L-1.5 mol / L, preferably 0.2 mol / L-1.0 mol / L; In step S3, the hydrothermal temperature is 70℃~190℃, preferably 100℃~160℃, and the heating time is 6 h~36 h, preferably 12 h-21 h. In step S3, the stabilizer is one or more of polyvinylpyrrolidone (PVP), urea, ammonia, and ethylenediamine, with a concentration of 0.05 mol / L to 1.0 mol / L, preferably 0.1 mol / L to 0.4 mol / L; In step S3, the precursor of B is H3BO3, with a concentration of 0.05 mol / L to 2.0 mol / L; preferably, the concentration is 0.15 mol / L to 0.55 mol / L.

[0015] In step S4, the electrode is placed in a muffle furnace and calcined in a nitrogen atmosphere. During the calcination process, the heating rate is controlled at 2℃ / min-10℃ / min, preferably 4℃ / min-8℃ / min, the calcination temperature is 200℃~700℃, preferably 400℃~600℃, and the time is 1 h-8 h, preferably 3 h-6 h. The electrode obtained after calcination is a nanostructure electrode composed of nanoparticles grown on nanowires (B-Cu). x Co y / Cu-E / T-CF, B-Cu x Co y The total loading of the Cu-E / T-CF electrode is 1 mg / cm³. 2 ~6.5mg / cm 2 The molar percentage of boron (B) ranges from 5-15%, that of copper (Cu) ranges from 15-55% (excluding the copper substrate, only the copper content of the catalyst layer), that of co (Co) ranges from 25-45%, and that of oxygen (O) ranges from 30-60%. After etching in step S2, the substrate surface is covered with numerous nanoparticles, with a nanoparticle loading of 0.05 mg / cm³. 2 ~0.35 mg / cm 2 The nanoparticles have a diameter of 0.005 μm to 2 μm; the nanoparticles on the Cu-E / T-CF surface are CuO.

[0016] The electrode prepared by this invention does not require additional binders and current collectors, which greatly improves the overall performance of the electrode; the through-type three-dimensional structure of the electrode can ensure that the electrolyte is fully wetted, effectively promoting the transport of reactants and products.

[0017] The present application has the following advantages compared with the prior art: The present application provides a three-dimensional copper-based copper-cobalt bimetallic self-supporting electrode, which is prepared by a three-step method of constant voltage etching, hydrothermal treatment and calcination.

[0018] The preparation process uses constant voltage etching, hydrothermal treatment and calcination, so the synthesis process is simple and convenient, the raw materials are cheap and widely available, and large-scale production can be carried out.

[0019] The three-dimensional copper-based copper-cobalt bimetallic electrode has good catalytic activity (the hydrogen evolution overpotential is 268 mV at a current density of 100 mA cm -2 , and the oxygen evolution overpotential is 346 mV at a current density of 50 mA cm -2 ), which indicates that the three-dimensional copper-based copper-cobalt oxide electrode has good performance in alkaline environment.

[0020] The present application relates to a copper-based dual-effect electrode and its preparation and application. The electrode preparation method comprises: pretreatment of the substrate, electrochemical etching reconstruction of the copper substrate by constant voltage method without adding additional Cu source, growth of copper-cobalt transition metal oxide and boride catalyst, and high-temperature calcination to prepare the copper-based dual-effect electrode. Through electrochemical etching reconstruction, an activation layer is generated on the surface of the substrate, which is rich in active groups and defects and can form stronger chemical bonding with the catalytic layer, thereby further improving the adhesion and the stability of the catalyst; the CuCo bimetallic has a synergistic effect, which promotes the transfer of electric charge in the electrolysis process, so that the electrode has dual-effect high electrocatalytic activity and high stability; the introduction of a small amount of B on the surface of CuCoO x can effectively regulate the surface electronic structure and micro morphology of the catalyst, not only increasing the exposure of active sites, but also strengthening the synergistic effect through amorphous / crystalline interface effect. This structure shows excellent oxygen evolution and hydrogen evolution activity and stability in alkaline medium. The (integrated) electrode prepared by the present application does not need to rely on a current collector and additional binder, simplifying the preparation process and reducing the cost. The electrode can be used to prepare electrolysis water hydrogen evolution electrodes, electrolysis water oxygen evolution electrodes, electrolysis seawater hydrogen evolution electrodes, electrolysis seawater oxygen evolution electrodes, metal-air battery charging cathode and anode electrodes, electrodes in fuel cell reactions under energy storage conditions, and carbon dioxide electro-reduction anode electrodes. BRIEF DESCRIPTION OF DRAWINGS

[0021] Figure 1Hydrogen evolution test was performed on the copper cobalt bimetallic electrode prepared in Example 1, i.e. in a three-electrode system of 1M KOH solution, with Hg / HgO as the reference electrode, a platinum sheet with a length x width of 1 cm x 1 cm as the counter electrode, and the electrode of the catalyst with a length x width of 1 cm x 1 cm as the working electrode, the potential range of the hydrogen evolution test (HER) was -0.2 V to -1.7 V (vs. Hg / HgO), and the scan rate was 5 mV s -1 The test was performed, and a linear voltammogram was plotted.

[0022] Figure 2 Oxygen evolution test was performed on the copper cobalt bimetallic electrode prepared in Example 1, i.e. in a three-electrode system of 1M KOH solution, with Hg / HgO as the reference electrode, a platinum sheet with a length x width of 1 cm x 1 cm as the counter electrode, and the electrode of the catalyst with a length x width of 1 cm x 1 cm as the working electrode, the potential range of the oxygen evolution test (OER) was 0 V to 1.0 V (vs. Hg / HgO), and the scan rate was 5 mV s -1 The test was performed, and a linear voltammogram was plotted.

[0023] Figure 3 Hydrogen evolution test was performed on the copper cobalt bimetallic electrode prepared in Example 1 and Comparative Example 1, Comparative Example 2, Comparative Example 3 and Comparative Example 4, i.e. in a three-electrode system of 1M KOH solution, with Hg / HgO as the reference electrode, a platinum sheet with a length x width of 1 cm x 1 cm as the counter electrode, and the electrode of the catalyst with a length x width of 1 cm x 1 cm as the working electrode, the potential range of the hydrogen evolution test (HER) was -0.2 V to -1.7 V (vs. Hg / HgO), and the scan rate was 5 mV s -1 The test was performed, and a linear voltammogram was plotted.

[0024] Figure 4 Oxygen evolution test was performed on the copper cobalt bimetallic electrode prepared in Example 1 and Comparative Example 1, Comparative Example 2, Comparative Example 3 and Comparative Example 4, i.e. in a three-electrode system of 1M KOH solution, with Hg / HgO as the reference electrode, a platinum sheet with a length x width of 1 cm x 1 cm as the counter electrode, and the electrode of the catalyst with a length x width of 1 cm x 1 cm as the working electrode, the potential range of the oxygen evolution test (OER) was 0 V to 1.0 V (vs. Hg / HgO), and the scan rate was 5 mV s -1 The test was performed, and a linear voltammogram was plotted.

[0025] Figure 5The copper cobalt bimetallic electrode prepared in Example 1 was subjected to hydrogen evolution test in comparison with Example 5, i.e. in a three-electrode system of 1 M KOH solution, with Hg / HgO as the reference electrode, a platinum sheet with a length x width of 1 cm x 1 cm as the counter electrode, and the electrode of the catalyst with a length x width of 1 cm x 1 cm as the working electrode, the potential range of the hydrogen evolution test (HER) was -0.2 V to -1.7 V (vs. Hg / HgO), and the scanning rate was 5 mV s -1 The test was carried out, and a linear voltammogram was plotted.

[0026] Figure 6 The copper cobalt bimetallic electrode prepared in Example 1 was subjected to oxygen evolution test in comparison with Example 5, i.e. in a three-electrode system of 1 M KOH solution, with Hg / HgO as the reference electrode, a platinum sheet with a length x width of 1 cm x 1 cm as the counter electrode, and the electrode of the catalyst with a length x width of 1 cm x 1 cm as the working electrode, the potential range of the oxygen evolution test (OER) was 0 V to 1.0 V (vs. Hg / HgO), and the scanning rate was 5 mV s -1 The test was carried out, and a linear voltammogram was plotted.

[0027] Figure 7 The copper cobalt bimetallic electrode prepared in Example 1 was subjected to hydrogen evolution test in comparison with Example 6, i.e. in a three-electrode system of 1 M KOH solution, with Hg / HgO as the reference electrode, a platinum sheet with a length x width of 1 cm x 1 cm as the counter electrode, and the electrode of the catalyst with a length x width of 1 cm x 1 cm as the working electrode, the potential range of the hydrogen evolution test (HER) was -0.2 V to -1.7 V (vs. Hg / HgO), and the scanning rate was 5 mV s -1 The test was carried out, and a linear voltammogram was plotted.

[0028] Figure 8 The copper cobalt bimetallic electrode prepared in Example 1 was subjected to oxygen evolution test in comparison with Example 6, i.e. in a three-electrode system of 1 M KOH solution, with Hg / HgO as the reference electrode, a platinum sheet with a length x width of 1 cm x 1 cm as the counter electrode, and the electrode of the catalyst with a length x width of 1 cm x 1 cm as the working electrode, the potential range of the oxygen evolution test (OER) was 0 V to 1.0 V (vs. Hg / HgO), and the scanning rate was 5 mV s -1 The test was carried out, and a linear voltammogram was plotted.

[0029] Figure 9 The copper cobalt bimetallic electrode prepared in Example 1 was subjected to oxygen evolution test in comparison with Example 6, i.e. in a three-electrode system of 1 M KOH solution, with Hg / HgO as the reference electrode, a platinum sheet with a length x width of 1 cm x 1 cm as the counter electrode, and the electrode of the catalyst with a length x width of 1 cm x 1 cm as the working electrode, the potential range of the oxygen evolution test (OER) was 0 V to 1.0 V (vs. Hg / HgO), and the scanning rate was 5 mV s -2The hydrogen evolution stability test was conducted over 100 hours in a three-electrode system of 1M KOH solution, using Hg / HgO as the reference electrode, a platinum sheet (1cm x 1cm) as the counter electrode, and the catalyst electrode (1cm x 1cm) as the working electrode, at a current density of 50 mA cm⁻¹. -2 The IT conducted a 100-hour stability hydrogen evolution test.

[0030] Figure 10 The copper-cobalt bimetallic electrode prepared in Example 1 had a current density of 50 mA / cm² in 1M KOH solution. -2 The oxygen evolution stability test was conducted over 100 hours in a three-electrode system of 1M KOH solution, using Hg / HgO as the reference electrode, a platinum sheet (1cm x 1cm) as the counter electrode, and the catalyst electrode (1cm x 1cm) as the working electrode, at a current density of 50 mA cm⁻¹. -2 The IT test was conducted for 100 hours of stability oxygen evolution.

[0031] Figure 11 The image shows a SEM image of the copper-cobalt bimetallic electrode prepared in Example 1. The surface morphology of the catalyst was characterized using a Regulus 8100 scanning electron microscope (SEM) with the voltage set to 5.00 kV. Detailed Implementation

[0032] The present invention is described in detail below through specific embodiments, but this does not limit the scope of protection of the present invention. Unless otherwise specified, the experimental methods used in the present invention are all conventional methods, and the experimental equipment, materials, reagents, etc. used can all be obtained commercially.

[0033] This invention provides a three-dimensional self-supporting electrode, its preparation method, and its application. The electrode uses copper foam as a substrate and is prepared using a three-step method of constant voltage etching / hydrothermal treatment / calcination to create a three-dimensional copper-cobalt bimetallic electrode. The electrode prepared by this method is applied to alkaline water electrolysis. The copper-cobalt bimetallic electrode consists of a dendritic structure composed of numerous nanoparticles grown on nanowires. The nanoparticle diameter ranges from 0.05 μm to 2 μm, and the nanowire length ranges from 170 nm to 350 nm. Electrochemical etching of the substrate increases the substrate loading area and generates oxygen-containing groups (such as -OH). These groups form strong chemical bonds with the CuCo bimetallic compound, resulting in no significant change in the catalyst's potential and catalytic performance during a 100-h stability test, demonstrating good stability and catalytic activity. The electrode prepared by this invention eliminates the need for additional binders such as current collectors, Nafion, and sugar alcohols, significantly improving the utilization rate of the catalyst on the electrode surface. The three-dimensional structure of the electrode ensures sufficient wetting of the electrolyte, facilitating the transport of reactants and products. The synergistic effect between the components and the three-dimensional layered porous nanostructure of the electrode accelerates water decomposition. This electrode can be used to prepare dual-effect electrodes for water electrolysis, seawater electrolysis, and carbon dioxide electroreduction reactions.

[0034] The present invention will be further described below: This invention provides a three-dimensional copper-cobalt oxide electrode prepared by a three-step method involving constant voltage etching, hydrothermal treatment, and calcination, and the method thereof. This method uses etched copper foam as a substrate to enhance the electrochemical effect of the composite material and improve its water electrolysis performance. The preparation method of the copper-cobalt oxide electrode includes: A material with a thickness of 0.5-1.5 mm and an area of ​​1.5-4.5 cm² is used. 2 The copper substrate was tableted at 0.5 MPa-3 MPa for 45-90 s on a tablet press, at 0.5 mol·L⁻¹. -1 ~3mol·L -1 Sonicate in HCl solution for 15 min ~ 50 min, rinse repeatedly with acetone or anhydrous ethanol and ultrapure water, and then dry in a vacuum oven at 30℃ ~ 90℃ for later use. This is denoted as T-CF. The treated copper substrate was electrochemically etched using a constant voltage method in one or more aqueous solutions of KCl and NaCl. After etching, the substrate was washed with ultrapure solvents to obtain a copper substrate rich in active groups and with a rough surface, denoted as Cu-E / T-CF; the concentration of KCl was 0.5 mol·L⁻¹. -1 -2 mol·L -1 The preferred concentration is 1.0 mol·L⁻¹. -1 -1.5 mol·L -1; the molar ratio of copper salt to cobalt salt is 0.1-10, the concentration of boric acid is 0.05-2.0 mol·L -1 , the concentration of urea is 0.05-1 mol·L -1 , the concentration of polyvinylpyrrolidone (PVP) is 0.05-1 mol·L -1 ; S3: 0.03 mol·L -1 copper salt, 0.07 mol·L -1 cobalt salt, 0.2 mol·L -1 boric acid, 0.2 mol·L -1 urea, and 0.1 mol·L -1 polyvinylpyrrolidone (PVP) are mixed into deionized water, and under normal temperature conditions, magnetic stirring is performed for 20-60 min to form a precursor cobalt-copper mixed solution, which is poured into a reaction kettle, and then Cu-E / T-CF is placed in the reaction kettle, and the reaction is carried out in a vacuum oven. After the reaction is completed, the reaction kettle is taken out and cooled, and then washed with acetone or anhydrous ethanol, ultrapure water several times, and then placed in a 70℃ vacuum oven for drying for 6-15 h to obtain an electrode a; the concentration of copper salt is 0.01 mol·L -1 -1.5 mol·L -1 , and the preferred concentration is 0.2 mol·L -1 -1.0 mol·L -1 ; the concentration of cobalt salt is 0.01 mol·L -1 -5.0 mol·L -1 , and the preferred concentration is 0.2 mol·L -1 -1.5 mol·L -1 ; the hydrothermal temperature is 70℃-190℃, the preferred temperature is 100℃-160℃, and the heating time is 6-36 h, and the preferred time is 12-21 h; The dried electrode a is placed in a muffle furnace and calcined in a nitrogen atmosphere to obtain a copper-based self-supporting electrode B-Cu x Co y / Cu-E / T-CF; the molar percentage of B is in the range of 5-15%, the molar percentage of Cu is in the range of 15-55% (not including the copper substrate, only the copper content of the catalytic layer), the molar percentage of Co is in the range of 25-45%, and the molar percentage of O is in the range of 30-60%.

[0035] Example 1 A copper foil with a thickness of 1 mm and an area of 3 cm 2The flaky foam copper CF was tabletted on a tablet press at 1 MPa for 45 s along the vertical thickness direction, then was ultrasonically treated in a 1 mol / L HCl solution for 30 min, was sequentially rinsed with acetone and deionized water, and was dried in an oven at 70°C for 10 h for standby, and was recorded as T-CF; the porosity of the CF was 95%, and the porosity of the T-CF was 85%; the T-CF was used as a working electrode in a water solution with a volume of 200 mL and a concentration of 0.5 mol / L KCl, a platinum sheet was used as a counter electrode, a silver chloride electrode was used as a reference electrode, the working electrode and the counter electrode were oppositely arranged, the distance between the working electrode and the counter electrode was 4 cm, and a constant voltage etching was performed at a voltage of 0.1 V for 15 min; after the etching, the T-CF was rinsed with deionized water, was dried in an oven at 70°C for 24 h, and was recorded as Cu-E / T-CF; a large number of nanoparticles grew on the surface of the Cu-E / T-CF; the loading amount of the nanoparticles was 0.25 mg / cm 2 , the diameter of the nanoparticles was 0.02 μm~1.5 μm, and the nanoparticles on the surface of the Cu-E / T-CF were CuO; 50 mL of a precursor copper-cobalt solution was prepared by mixing 0.03 mol / L Cu(NO3)2·3H2O, 0.07 mol / L CoCl2·6H2O, 0.2 mol / L boric acid, 0.2 mol / L urea, and 0.1 mol / L polyvinylpyrrolidone (PVP) in water and stirring for 30 min: The precursor copper-cobalt mixed solution and the pretreated Cu-E / T-CF were placed in a reaction kettle and reacted in a 100°C vacuum oven for 18 h. After the reaction, the reaction kettle was taken out and cooled to room temperature, the hydrothermally treated foam copper was sequentially rinsed with acetone and deionized water, and was placed in a 60°C oven for 10 h to obtain a precursor a: The precursor a was placed in a tube furnace and calcined at 300°C for 2 h under nitrogen protection to obtain an electrode B-Cu3Co7 / Cu-E / T-CF; T-CF indicates that the substrate CF was tabletted, Cu-E / T-CF indicates that the substrate T-CF was electrochemically etched, B-Cu3Co7 / Cu-E / T-CF indicates an electrode obtained by hydrothermal calcination of the Cu-E / T-CF, the numbers indicate the addition concentrations of Cu 0.03 mol / L and Co 0.07 mol / L in water, and B indicates that boric acid is added; The electrode comprises a substrate, copper cobalt oxide and cobalt boride compound catalyst, the copper cobalt oxide and cobalt boride compound catalyst are attached to the substrate; the copper cobalt oxide presents a nano-wire structure, is composed of CuO, Co3O4 and CuCo2O4, contains etched CuO, the length of the nano-wire is 210 nm to 350 nm, the diameter of the nano-wire is 0.01 μm to 1 μm, and the loading amount of the copper cobalt oxide on the substrate is 5.0 mg / cm 2 (contains etched CuO), the cobalt boride compound presents a nano-particle structure, the diameter of the nano-particle is 0.05 μm to 2 μm, the cobalt boride compound is CoB, and the loading amount on the substrate is 1.0 mg / cm 2 The total loading amount of the copper cobalt oxide and the cobalt boride compound on the substrate in the B-Cu3Co7 / Cu-E / T-CF electrode is 6.0 mg / cm 2 The above nano-structure is obtained by SEM image.

[0036] Example 2 A piece of foam copper CF with a thickness of 1 mm and an area of 3 cm 2 is pressed on a tablet press along the vertical thickness direction at 1 MPa for 45 s, then is ultrasonically treated in a 1 mol / L HCl solution for 30 min, is sequentially washed with acetone and deionized water, and is placed in an oven for drying at 70℃ for 10 h for standby, and is recorded as T-CF; the porosity of the CF is 95%, and the porosity of the T-CF is 85%; The T-CF is used as a working electrode in a water solution with a volume of 200 mL and a concentration of 0.5 mol / L KCl, a platinum sheet is used as a counter electrode, a silver chloride electrode is used as a reference electrode, the working electrode and the counter electrode are oppositely arranged, the distance between the working electrode and the counter electrode is 4 cm, and the voltage is 0.1 V, and then constant voltage etching is performed for 15 min, after etching, the T-CF is washed with deionized water, is placed in an oven for drying at 70℃ for 24 h, and is recorded as Cu-E / T-CF, a large number of nano-particles grow on the surface of the Cu-E / T-CF; the loading amount of the nano-particles is 0.25 mg / cm 2 , the diameter of the nano-particles is 0.02 μm to 1.5 μm, and the nano-particles on the surface of the Cu-E / T-CF are CuO; 50 mL of a copper cobalt solution precursor is formed by mixing 0.07 mol / L Cu(NO3)2·3H2O, 0.03 mol / L CoCl2·6H2O, 0.2 mol / L boric acid, 0.2 mol / L urea and 0.1 mol / L polyvinylpyrrolidone (PVP) in water and stirring for 30 min; The precursor copper cobalt mixed solution and the pretreated Cu-E / T-CF were put into a reaction kettle, and reacted in a 100℃ vacuum oven for 18 h. After the reaction was completed, the reaction kettle was taken out and cooled to room temperature, and the hydrothermal foamed copper was rinsed with acetone and deionized water in turn, and then was put into a 60℃ oven for 10 h to obtain a precursor a; The precursor a was put into a tube furnace and calcined at 300℃ for 2 h under nitrogen protection to obtain an electrode B-Cu7Co3 / Cu-E / T-CF; T-CF represents that the substrate CF is tabletted, Cu-E / T-CF is that the substrate T-CF is electrochemically etched, B-Cu7Co3 / Cu-E / T-CF represents the electrode obtained after the substrate Cu-E / T-CF is hydrothermally calcined, the numbers indicate the addition concentrations of Cu 0.07 mol / L and Co 0.03 mol / L in water, and B indicates that boric acid is added; The electrode comprises a substrate, a copper cobalt oxide and a cobalt boride compound catalyst, and the copper cobalt oxide and the cobalt boride compound catalyst are attached to the substrate; the copper cobalt oxide presents a nanowire structure and is composed of CuO, Co3O4 and CuCo2O4 (including CuO generated after etching), the length of the nanowire is 170 nm to 320 nm, the diameter of the nanowire is 0.01 μm to 0.95 μm, and the loading amount of the copper cobalt oxide on the substrate is 4.1 mg / cm 2 (including CuO generated after etching), the cobalt boride compound presents a nanoparticle structure, the diameter of the nanoparticle is 0.25 μm to 2 μm, the cobalt boride compound is CoB, and the loading amount of the cobalt boride compound on the substrate is 0.8 mg / cm 2 The total loading amount of the copper cobalt oxide and the cobalt boride compound on the substrate in the B-Cu7Co3 / Cu-E / T-CF electrode is 4.9 mg / cm 2 The above nanostructures are obtained through SEM images.

[0037] Example 3 A sheet-shaped foamed copper CF with a thickness of 1 mm and an area of 3 cm 2 was tabletted on a tablet press along the vertical thickness direction at 1 MPa for 45 s, and then was ultrasonically treated in a 1 mol / L HCl solution for 30 min, and then was rinsed with acetone and deionized water in turn and was dried in an oven at 70℃ for 10 h for standby, and was recorded as T-CF; the porosity of the CF is 95%, and the porosity of the T-CF is 85%; The T-CF is taken as a working electrode in a water solution with a volume of 200 mL and a concentration of 0.5 mol / L KCl, a platinum sheet is taken as a counter electrode, a silver chloride electrode is taken as a reference electrode, the working electrode and the counter electrode are oppositely arranged, the distance between the working electrode and the counter electrode is 4 cm, and the voltage is 0.1 V, and then constant voltage etching is performed for 15 min, and then the electrode is cleaned by deionized water, and then is placed in an oven and dried at 70℃ for 24 h, and is recorded as Cu-E / T-CF, and a large number of nano-particles grow on the surface of the Cu-E / T-CF; the loading amount of the nano-particles is 0.25 mg / cm 2 , the diameter of the nano-particles is 0.02 μm~1.5 μm, and the nano-particles on the surface of the Cu-E / T-CF are CuO; 50 mL of a precursor copper-cobalt solution is prepared by mixing 0.05 mol / L Cu(NO3)2·3H2O, 0.05 mol / L CoCl2·6H2O, 0.2 mol / L boric acid, 0.2 mol / L urea and 0.1 mol / L polyvinylpyrrolidone (PVP) in water, and stirring for 30 min: The precursor copper-cobalt mixed solution and the pretreated Cu-E / T-CF are placed in a reaction kettle, and reaction is performed in a 100℃ vacuum oven for 18 h. After the reaction is completed, the reaction kettle is taken out and cooled to room temperature, and the hydrothermal foam copper is cleaned by acetone and deionized water in sequence, and then is placed in a 60℃ oven for 10 h to obtain a precursor a: The precursor a is placed in a tube furnace and calcined under nitrogen protection, the calcination temperature is 300℃, and the calcination time is 2 h; and an electrode B-Cu5Co5 / Cu-E / T-CF is obtained; T-CF represents that the substrate CF is tabletted, Cu-E / T-CF represents that the substrate T-CF is electrochemically etched, B-Cu5Co5 / Cu-E / T-CF represents an electrode obtained by hydrothermal calcination of the substrate Cu-E / T-CF, and the numbers indicate the adding concentrations of Cu 0.05 mol / L and Co 0.05 mol / L in water; and B indicates that boric acid is added; The electrode comprises a substrate, a copper-cobalt oxide and a cobalt-boron compound catalyst, and the copper-cobalt oxide and the cobalt-boron compound catalyst are attached to the substrate; the copper-cobalt oxide presents a nano-wire structure, is composed of CuO, Co3O4 and CuCo2O4 (including CuO generated by etching), the length of the nano-wire is 210 nm~340 nm, the diameter of the nano-wire is 0.11 μm~1 μm, and the loading amount of the copper-cobalt oxide on the substrate is 4.3 mg / cm 2 (including CuO generated by etching after etching), the cobalt-boron compound presents a nano-particle structure, the diameter of the nano-particle is 0.05 μm~1.9 μm, the cobalt-boron compound is CoB, and the loading amount on the substrate is 0.9 mg / cm 2The total loading of copper-cobalt oxides and cobalt-boron compounds on the substrate in the B-Cu5Co5 / Cu-E / T-CF electrode was 5.2 mg / cm³. 2 The above nanostructures were obtained through SEM images.

[0038] Example 4 A material with a thickness of 1 mm and an area of ​​3 cm² 2 Flake-shaped copper foam (CF) was compressed at 1 MPa for 45 seconds along the perpendicular thickness direction on a tablet press, then ultrasonically treated in 1 mol / L HCl solution for 30 min, rinsed successively with acetone and deionized water, and dried in an oven at 70℃ for 10 h for later use. This was designated as T-CF. The porosity of CF was 95%, and the porosity of T-CF was 85%. Using T-CF as the working electrode, constant voltage etching was performed for 15 min in 200 mL of 0.5 mol / L KCl aqueous solution, with a platinum sheet as the counter electrode and a silver chloride electrode as the reference electrode. The working electrode and counter electrode surfaces were positioned opposite each other at a distance of 4 cm, and the voltage was 0.1 V. After etching, the surface was rinsed with deionized water and dried in an oven at 70 °C for 24 h. This result was designated Cu-E / T-CF. Numerous nanoparticles grew on the surface of Cu-E / T-CF, with a loading of 0.25 mg / cm³. 2 The nanoparticles have a diameter of 0.02 μm to 1.5 μm, and the nanoparticles on the Cu-E / T-CF surface are CuO. 50 mL of solutions containing 0.01 mol / L Cu(NO3)2·3H2O, 0.09 mol / L CoCl2·6H2O, 0.2 mol / L boric acid, 0.2 mol / L urea, and 0.1 mol / L polyvinylpyrrolidone (PVP) were added to water and mixed, and stirred for 30 min to form a copper-cobalt precursor solution. The precursor copper-cobalt mixed solution and the pretreated Cu-E / T-CF were placed in a reactor and reacted in a vacuum oven at 100℃ for 18 h. After the reaction, the reactor was removed and cooled to room temperature. The hydrothermally heated copper foam was rinsed with acetone and deionized water in sequence, and then placed in a 60℃ oven for 10 h to obtain precursor a: Precursor a was placed in a tube furnace and calcined under nitrogen protection at 300°C for 2 hours to obtain electrode B-Cu1Co9 / Cu-E / T-CF. T-CF means that the substrate CF is pressed into a sheet, Cu-E / T-CF means that the substrate T-CF is electrochemically etched, B-Cu1Co9 / Cu-E / T-CF means that the electrode obtained after hydrothermal roasting of the substrate Cu-E / T-CF, the numbers indicate the added concentrations in water Cu 0.01 mol / L, Co 0.09 mol / L, B means that boric acid is added; The electrode comprises a substrate, copper cobalt oxide and cobalt boride catalyst, the copper cobalt oxide and cobalt boride catalyst are attached to the substrate; the copper cobalt oxide presents a nanowire structure, is composed of CuO, Co3O4 and CuCo2O4 (including CuO produced by etching), the length of the nanowire is 230 nm-340 nm, the diameter of the nanowire is 0.01 μm-0.95 μm, and the loading amount of the copper cobalt oxide on the substrate is 4.5 mg / cm 2 (including CuO produced by etching after etching), the cobalt boride presents a nanoparticle structure, the diameter of the nanoparticle is 0.45 μm-2 μm, the cobalt boride is CoB, and the loading amount on the substrate is 1.1 mg / cm 2 , and the total loading amount of the copper cobalt oxide and the cobalt boride on the substrate in the B-Cu1Co9 / Cu-E / T-CF electrode is 5.6 mg / cm 2 , and the above nanostructure is obtained by SEM image.

[0039] Example 5 A sheet-shaped copper foam CF with a thickness of 1 mm and an area of 3 cm 2 is pressed into a sheet on a sheet press along the direction perpendicular to the thickness at 1 MPa for 45 s, and then is ultrasonically treated in a 1 mol / L HCl solution for 30 min, is sequentially washed with acetone and deionized water, and is placed in an oven to be dried at 70°C for 10 h for standby, and is recorded as T-CF; the porosity of the CF is 95%, and the porosity of the T-CF is 85%; The T-CF is used as a working electrode in a water solution with a volume of 200 mL and a concentration of 0.5 mol / L KCl, a platinum sheet is used as a counter electrode, a silver chloride electrode is used as a reference electrode, the working electrode and the counter electrode are oppositely arranged, the distance between the working electrode and the counter electrode is 4 cm, and a constant voltage etching is performed at a voltage of 0.1 V for 15 min, after etching, the working electrode is washed with deionized water, is placed in an oven to be dried at 70°C for 24 h, and is recorded as Cu-E / T-CF, a large number of nano-particles grow on the surface of the Cu-E / T-CF; the loading amount of the nano-particles is 0.25 mg / cm 2 , the diameter of the nano-particles is 0.02 μm-1.5 μm, and the nano-particles on the surface of the Cu-E / T-CF are CuO; A precursor copper cobalt solution was prepared by mixing 50 mL of Cu(NO3)2·3H2O, CoCl2·6H2O, boric acid, urea and polyvinylpyrrolidone (PVP) with a final concentration of 0.03 mol / L, 0.07 mol / L, 0.2 mol / L, 0.2 mol / L and 0.1 mol / L respectively in water and stirring for 30 min: The precursor copper cobalt mixed solution and the pretreated Cu-E / T-CF were placed in a reaction kettle and reacted in a vacuum oven at 100°C for 18 h. After the reaction was completed, the reaction kettle was removed and cooled to room temperature. The hydrothermal foam copper was rinsed with acetone and deionized water in turn, and then placed in an oven at 60°C for 10 h to obtain a precursor a: The precursor a was placed in a tube furnace and calcined at 200°C for 2 h under nitrogen protection to obtain an electrode B-Cu3Co7-200 / Cu-E / T-CF. T-CF indicates that the substrate CF was tabletted, Cu-E / T-CF indicates that the substrate T-CF was electrochemically etched, B-Cu3Co7-200 / Cu-E / T-CF indicates the electrode obtained after hydrothermal calcination of Cu-E / T-CF, the numbers indicate the addition concentration of Cu 0.03 mol / L and Co 0.07 mol / L in water, B indicates that boric acid was added, and 200 indicates the calcination temperature. The electrode comprises a substrate, a copper cobalt oxide and a cobalt boride compound catalyst, and the copper cobalt oxide and the cobalt boride compound catalyst are attached to the substrate; the copper cobalt oxide has a nanowire structure and is composed of CuO, Co3O4 and CuCo2O4 (including CuO produced by etching), the length of the nanowire is 170 nm to 300 nm, the diameter of the nanowire is 0.31 μm to 1 μm, and the loading amount of the copper cobalt oxide on the substrate is 4.2 mg / cm 2 (including CuO produced by etching after etching), the cobalt boride compound has a nanoparticle structure, the diameter of the nanoparticle is 0.55 μm to 2 μm, the cobalt boride compound is CoB, and the loading amount on the substrate is 0.9 mg / cm 2 The total loading amount of the copper cobalt oxide and the cobalt boride compound on the substrate in the B-Cu3Co7-200 / Cu-E / T-CF electrode is 5.1 mg / cm 2 The above nanostructures were obtained by SEM images.

[0040] Example 6 A piece of T-CF with a thickness of 1 mm and an area of 3 cm 2The sheet-shaped foam copper CF was tabletted on a tablet press at 1 MPa for 45 s along the vertical thickness direction, then was put into a 1 mol / L HCl solution for ultrasonic treatment for 30 min, was sequentially rinsed with acetone and deionized water, and was put into an oven for drying at 70 DEG C for 10 h for standby, and was recorded as T-CF; the porosity of the CF was 95%, and the porosity of the T-CF was 85%; The T-CF was taken as a working electrode in a water solution with a volume of 200 mL and a concentration of 0.5 mol / L KCl, a platinum sheet was taken as a counter electrode, a silver chloride electrode was taken as a reference electrode, the working electrode and the counter electrode were oppositely arranged, the distance between the working electrode and the counter electrode was 4 cm, and constant voltage etching was carried out at a voltage of 0.1 V for 15 min, then the etched T-CF was rinsed with deionized water, was put into an oven for drying at 70 DEG C for 24 h, and was recorded as Cu-E / T-CF, a large number of nano-particles grew on the surface of the Cu-E / T-CF; the loading amount of the nano-particles was 0.25 mg / cm 2 , the diameter of the nano-particles was 0.02 μm~1.5 μm, and the nano-particles on the surface of the Cu-E / T-CF were CuO; 50 mL of precursor solution was prepared by adding 0.03 mol / L Cu(NO3)2·3H2O, 0.07 mol / L CoCl2·6H2O, 0.2 mol / L boric acid, 0.2 mol / L urea and 0.1 mol / L polyvinylpyrrolidone (PVP) into water and stirring for 30 min: The precursor copper-cobalt mixed solution and the pretreated Cu-E / T-CF were put into a reaction kettle and reacted in a 100 DEG C vacuum oven for 18 h. After the reaction, the reaction kettle was taken out and cooled to room temperature, the hydrothermally treated foam copper was sequentially rinsed with acetone and deionized water, and was put into a 60 DEG C oven for 10 h to obtain a precursor a: The precursor a was put into a tube furnace and was calcined at 400 DEG C under nitrogen protection for 2 h to obtain an electrode B-Cu3Co7-400 / Cu-E / T-CF; T-CF indicates that the substrate CF was tabletted, Cu-E / T-CF indicates that the substrate T-CF was electrochemically etched, B-Cu3Co7-400 / Cu-E / T-CF indicates an electrode obtained by hydrothermal calcination of the Cu-E / T-CF, the numbers indicate the addition concentrations of Cu and Co in water, Cu 0.03 mol / L and Co 0.07 mol / L, B indicates that boric acid is added, and 400 indicates the calcination temperature; The electrode comprises a substrate, copper cobalt oxide and cobalt boride compound catalyst, the copper cobalt oxide and cobalt boride compound catalyst are attached to the substrate; the copper cobalt oxide presents a nanowire structure, is composed of CuO, Co3O4 and CuCo2O4 (including CuO produced by etching), the length of the nanowire is 170 nm to 340 nm, the diameter of the nanowire is 0.01 μm to 0.9 μm, and the loading amount of the copper cobalt oxide on the substrate is 5.0 mg / cm 2 The cobalt boride compound presents a nanoparticle structure, the diameter of the nanoparticle is 0.35 μm to 2 μm, the cobalt boride compound is CoB, and the loading amount on the substrate is 0.8 mg / cm 2 The total loading amount of the copper cobalt oxide and the cobalt boride compound on the substrate in the B-Cu3Co7-400 / Cu-E / T-CF electrode is 5.8 mg / cm 2 The above nanostructure is obtained through a SEM image.

[0041] Example 7 A piece of foamed copper CF with a thickness of 1 mm and an area of 3 cm 2 is pressed on a tablet press along the vertical thickness direction at 1 MPa for 45 s, and then is ultrasonically treated in a 1 mol / L HCl solution for 30 min, is sequentially washed with acetone and deionized water, and is placed in an oven for drying at 70℃ for 10 h for standby, and is recorded as T-CF; the porosity of the CF is 95%, and the porosity of the T-CF is 85%; The T-CF is used as a working electrode in a water solution with a volume of 200 mL and a concentration of 0.5 mol / L KCl, a platinum sheet is used as a counter electrode, a silver chloride electrode is used as a reference electrode, the working electrode and the counter electrode are oppositely arranged, the distance between the working electrode and the counter electrode is 4 cm, and a constant voltage etching is performed at 0.1 V for 15 min, after the etching, the T-CF is washed with deionized water and is placed in an oven for drying at 70℃ for 24 h, and is recorded as Cu-E / T-CF, a large number of nano-particles grow on the surface of the Cu-E / T-CF; the loading amount of the nano-particles is 0.25 mg / cm 2 , the diameter of the nano-particles is 0.02 μm to 1.5 μm, and the nano-particles on the surface of the Cu-E / T-CF are CuO; 50 mL of a precursor solution is formed by adding 0.03 mol / L Cu(NO3)2·3H2O, 0.07 mol / L CoCl2·6H2O, 0.2 mol / L boric acid, 0.2 mol / L urea and 0.1 mol / L polyvinylpyrrolidone (PVP) into water and stirring for 30 min: The precursor copper cobalt mixed solution and the pretreated Cu-E / T-CF are put into a reaction kettle, and reacted in a 100℃ vacuum oven for 18 h. After the reaction is completed, the reaction kettle is taken out and cooled to room temperature, and the hydrothermal foamed copper is sequentially rinsed with acetone and deionized water, and then put into a 60℃ oven for 10 h to obtain a precursor a: The precursor a is put into a tube furnace and calcined at 500℃ for 2 h under nitrogen protection to obtain an electrode B-Cu3Co7-500 / Cu-E / T-CF. T-CF represents that the substrate CF is tabletted, Cu-E / T-CF represents that the substrate T-CF is electrochemically etched, B-Cu3Co7-500 / Cu-E / T-CF represents an electrode obtained by hydrothermal calcination of Cu-E / T-CF, the numbers indicate the addition concentrations of Cu 0.03 mol / L and Co 0.07 mol / L in water, B indicates that boric acid is added, and 500 indicates the calcination temperature; The electrode comprises a substrate, a copper cobalt oxide and a cobalt boride compound catalyst, and the copper cobalt oxide and the cobalt boride compound catalyst are attached to the substrate; the copper cobalt oxide presents a nanowire structure and is composed of CuO, Co3O4 and CuCo2O4 (including CuO generated by etching), the length of the nanowire is 190 nm to 320 nm, the diameter of the nanowire is 0.35 μm to 1 μm, and the loading amount of the copper cobalt oxide on the substrate is 4.8 mg / cm 2 (including CuO generated by etching), the cobalt boride compound presents a nanoparticle structure, the diameter of the nanoparticle is 0.65 μm to 2 μm, the cobalt boride compound is CoB, and the loading amount on the substrate is 0.7 mg / cm 2 The total loading amount of the copper cobalt oxide and the cobalt boride compound on the substrate in the B-Cu3Co7-500 / Cu-E / T-CF electrode is 5.5 mg / cm 2 The above nanostructures are obtained by SEM images.

[0042] Comparative Example 1 The preparation method of T-CF is the same as that of T-CF in Example 1.

[0043] Comparative Example 2 The preparation method of Cu-E / T-CF is the same as that of Cu-E / T-CF in Example 1.

[0044] Comparative Example 3 A piece of T-CF with a thickness of 1 mm and an area of 3 cm 2The flaky foam copper CF was tabletted on a tablet press at 1 MPa for 45 s along the vertical thickness direction, followed by ultrasonic treatment in 1 mol / L HCl solution for 30 min, and then washed with acetone and deionized water successively and dried in an oven at 70℃ for 10 h for standby, denoted as T-CF; the porosity of CF was 95%, and the porosity of T-CF was 85%; T-CF was used as the working electrode in a water solution with a volume of 200 mL and a concentration of 0.5 mol / L KCl, a platinum plate was used as the counter electrode, and a silver chloride electrode was used as the reference electrode; the working electrode and the counter electrode were oppositely arranged, the distance between the two was 4 cm, and the voltage was 0.1 V; constant voltage etching was performed for 15 min, and then the electrode was washed with deionized water and dried in an oven at 70℃ for 24 h, denoted as Cu-E / T-CF; the loading amount was 0.25 mg / cm 2 , the nanoparticle diameter was 0.02 μm~1.5 μm, and the nanoparticles on the surface of Cu-E / T-CF were CuO; 50 mL of precursor solution was prepared by adding 0.03 mol / L Cu(NO3)2·3H2O, 0.2 mol / L boric acid, 0.2 mol / L urea and 0.1 mol / L polyvinylpyrrolidone (PVP) into water and stirring for 30 min: The precursor solution and the pretreated Cu-E / T-CF were placed in a reaction kettle and reacted in a 100℃ vacuum oven for 18 h. After the reaction was completed, the reaction kettle was taken out and cooled to room temperature, the foam copper was washed with acetone and deionized water successively, and then placed in a 60℃ oven for 10 h to obtain precursor a: The precursor a was placed in a tube furnace and calcined under nitrogen protection at 300℃ for 2 h to obtain electrode B-Cu3 / Cu-E / T-CF; T-CF indicates that the substrate CF was tabletted, Cu-E / T-CF indicates that the substrate T-CF was electrochemically etched, B-Cu3 / Cu-E / T-CF indicates the electrode obtained after hydrothermal calcination of Cu-E / T-CF, and the numbers indicate the addition concentration of Cu in water Cu0.03 mol / L, and B indicates that boric acid is added; The electrode comprises a substrate and copper oxide, and the copper oxide catalyst is attached to the substrate; the copper oxide (CuO) is in the form of nanoparticles, and the total loading amount of CuO on the substrate in the B-Cu3 / Cu-E / T-CF electrode includes CuO produced by etching and CuO produced by hydrothermal calcination of copper oxide is 1.4 mg / cm 2 , the nanoparticle diameter is 1.1 μm~2 μm, and the above nanostructure is obtained by SEM image.

[0045] Comparative Example 4 A piece of foam copper CF with a thickness of 1 mm and an area of 3 cm 2 was pressed on a tablet press along the vertical thickness direction at 1 MPa for 45 s, then placed in a 1 mol / L HCl solution for ultrasonic treatment for 30 min, rinsed with acetone and deionized water in turn, and then placed in an oven at 70°C for 10 h for drying, and marked as T-CF; the porosity of CF was 95%, and the porosity of T-CF was 85%; T-CF was used as the working electrode in a 200 mL aqueous solution with a concentration of 0.5 mol / L KCl, with a platinum sheet as the counter electrode and a silver chloride electrode as the reference electrode, the working electrode and the counter electrode were arranged opposite to each other with a distance of 4 cm between them, and the voltage was 0.1 V, and constant voltage etching was carried out for 15 min; after etching, the electrode was rinsed with deionized water and then placed in an oven at 70°C for 24 h for drying, and marked as Cu-E / T-CF; the loading was 0.25 mg / cm 2 , the nanoparticle diameter was 0.02 μm~1.5 μm, and the nanoparticles on the surface of Cu-E / T-CF were CuO; 50 mL of precursor solution was prepared by mixing 0.07 mol / L CoCl2·6H2O, 0.2 mol / L boric acid, 0.2 mol / L urea, and 0.1 mol / L polyvinylpyrrolidone (PVP) with stirring for 30 min: The precursor solution and the pretreated Cu-E / T-CF were placed in a reaction kettle and reacted in a 100°C vacuum oven for 18 h. After the reaction was completed, the reaction kettle was removed and cooled to room temperature, the foam copper was rinsed with acetone and deionized water in turn, and then placed in a 60°C oven for 10 h to obtain precursor a: The precursor a was placed in a tube furnace and calcined under nitrogen protection at 300°C for 2 h to obtain electrode B-Co7 / Cu-E / T-CF; T-CF indicates that the substrate CF has been pressed, Cu-E / T-CF is the substrate T-CF that has been electrochemically etched, B-Co7 / Cu-E / T-CF indicates the electrode obtained after hydrothermal calcination of Cu-E / T-CF, the number indicates the addition concentration of Co in water Co0.07 mol / L, and B indicates that boric acid has been added; The electrode comprises a substrate, copper cobalt oxide and cobalt boride catalyst, the copper cobalt oxide and cobalt boride catalyst are attached to the substrate; the copper cobalt oxide presents a nano-wire structure, is composed of CuO, Co3O4 and CuCo2O4 (including CuO produced by etching), the length of the nano-wire is 170 nm to 270 nm, the diameter of the nano-wire is 0.41 μm to 0.9 μm, the loading amount of Co3O4 on the substrate is 1.5 mg / cm 2 , the cobalt boride presents a nano-particle structure, the diameter of the nano-particle is 0.25 μm to 2 μm, the cobalt boride is CoB, the loading amount on the substrate is 0.7 mg / cm 2 , the total loading amount of the copper cobalt oxide and the cobalt boride on the substrate in the B-Co7 / Cu-E / T-CF electrode is 2.45 mg / cm 2 , the above nano-structure is obtained by SEM image.

[0046] Comparative Example 5 A piece of foam copper CF with a thickness of 1 mm and an area of 3 cm 2 is pressed on a tablet press along the vertical thickness direction at 1 MPa for 45 s, then is ultrasonically treated in a 1 mol / L HCl solution for 30 min, is sequentially washed with acetone and deionized water, and is placed in an oven for drying at 70℃ for 10 h for standby, and is recorded as T-CF; the porosity of the CF is 95%, and the porosity of the T-CF is 85%; 50 mL of a precursor solution is prepared by adding 0.03 mol / L Cu(NO3)2·3H2O, 0.07 mol / L CoCl2·6H2O, 0.2 mol / L boric acid, 0.2 mol / L urea and 0.1 mol / L polyvinylpyrrolidone (PVP) into water and stirring for 30 min: The precursor solution and the pretreated T-CF are placed in a reaction kettle and reacted in a 100℃ vacuum oven for 18 h. After the reaction is completed, the reaction kettle is taken out for cooling, the foam copper is sequentially washed with acetone and deionized water, and is placed in a 60℃ oven for 10 h to obtain a precursor a: The precursor a is placed in a tube furnace and calcined under nitrogen protection at 300℃ for 2 h to obtain an electrode B-Cu3Co7 / T-CF; T-CF indicates that the substrate CF is pressed, B-Cu3Co7 / T-CF indicates an electrode obtained by hydrothermal calcination of T-CF, the numbers indicate the addition concentrations of Cu 0.03 mol / L and Co 0.07 mol / L in water, and B indicates that boric acid is added; The electrode comprises a substrate, copper cobalt oxide and cobalt boride compound catalyst, the copper cobalt oxide and cobalt boride compound catalyst are attached to the substrate; the copper cobalt oxide presents a nanowire structure, is composed of CuO, Co3O4 and CuCo2O4 (including CuO produced by etching), the length of the nanowire is 170 nm to 330 nm, the diameter of the nanowire is 0.21 μm to 1 μm, and the loading amount of the copper cobalt oxide on the substrate is 4.5 mg / cm 2 (including CuO produced after etching), the cobalt boride compound presents a nanoparticle structure, the diameter of the nanoparticle is 0.25 μm to 2 μm, the cobalt boride compound is CoB, and the loading amount on the substrate is 1 mg / cm 2 The total loading amount of the copper cobalt oxide and the cobalt boride compound on the substrate in the B-Cu3Co7 / T-CF electrode is 5.5 mg / cm 2 The above nanostructure is obtained through a SEM image.

[0047] Comparative Example 6 A sheet-shaped copper foam CF with a thickness of 1 mm and an area of 3 cm 2 is pressed on a tablet press along the vertical thickness direction at 1 MPa for 45 s, and then is ultrasonically treated in a 1 mol / L HCl solution for 30 min, is sequentially washed with acetone and deionized water, and is placed in an oven for drying at 70°C for 10 h for standby, and is recorded as T-CF; the porosity of the CF is 95%, and the porosity of the T-CF is 85%; The T-CF is used as a working electrode in a water solution with a volume of 200 mL and a concentration of 0.5 mol / L KCl, a platinum sheet is used as a counter electrode, a silver chloride electrode is used as a reference electrode, the working electrode and the counter electrode are oppositely arranged, the distance between the working electrode and the counter electrode is 4 cm, and a constant voltage etching is performed at a voltage of 0.1 V for 15 min, after etching, the T-CF is washed with deionized water and is placed in an oven for drying at 70°C for 24 h, and is recorded as Cu-E / T-CF; the loading amount is 0.25 mg / cm 2 , the nanoparticle diameter is 0.02 μm to 1.5 μm, and the nanoparticles on the surface of the Cu-E / T-CF are CuO; 50 mL of a precursor solution is formed by adding 0.03 mol / L Cu(NO3)2·3H2O, 0.07 mol / L CoCl2·6H2O, 0.2 mol / L urea and 0.1 mol / L polyvinylpyrrolidone (PVP) into water and stirring for 30 min: The precursor solution and the pretreated Cu-E / T-CF were put into a reaction kettle, and reacted in a vacuum oven at 100℃ for 18h. After the reaction, the reaction kettle was taken out and cooled to room temperature, and the foamed copper was washed with acetone and deionized water in sequence, and then put into an oven at 60℃ for 10h to obtain the precursor a: The precursor a was put into a tube furnace and calcined under nitrogen protection at 300℃ for 2h to obtain the electrode Cu3Co7 / Cu-E / T-CF. T-CF represents that the substrate CF is tabletted, Cu-E / T-CF represents that the substrate T-CF is electrochemically etched, Cu3Co7 / Cu-E / T-CF represents the electrode obtained after hydrothermal calcination of Cu-E / T-CF, and the numbers indicate the addition concentration of Cu 0.03 mol / L and Co 0.07 mol / L in water; The electrode comprises a substrate and a copper cobalt oxide catalyst, and the copper cobalt oxide catalyst is attached to the substrate; the copper cobalt oxide presents a nanowire structure and is composed of CuO, Co3O4 and CuCo2O4 (including CuO generated by etching), the length of the nanowire is 170 nm to 310 nm, the diameter of the nanowire is 0.21 μm to 1 μm, and the loading amount of the copper cobalt oxide on the substrate is 5.1 mg / cm 2 (including CuO generated by etching), and the total loading amount of the copper cobalt oxide on the substrate in the Cu3Co7 / Cu-E / T-CF electrode is 5.1 mg / cm 2 The above nanostructure is obtained by SEM image.

[0048] Linear sweep voltammetry (LSV) is an important electrochemical analysis technique that studies the redox behavior of a substance by applying a linearly varying voltage and measuring the response current. The horizontal axis of the LSV curve represents the potential, and the vertical axis represents the current; it can be used to compare the onset potential and current density of different catalysts. In the field of water electrolysis oxygen evolution reaction (OER) and hydrogen evolution reaction (HER), the smaller the overpotential corresponding to a certain current density, the better the catalytic performance of the electrode, which can indicate that the OER and HER have lower energy consumption. In this experiment, a three-electrode system was used in 1M KOH solution, Hg / HgO was used as the reference electrode, platinum sheet with length x width of 1 cm x 1 cm was used as the counter electrode, and the electrode prepared in the above examples or comparative examples was used as the working electrode. The potential range for oxygen evolution test (OER) was 0V to 1.0V (vs. Hg / HgO), the potential range for hydrogen evolution test (HER) was -0.2V to -1.6V (vs. Hg / HgO), and the scanning rate was 5 mV s -1 for testing.

[0049] All test potentials are converted using a reversible hydrogen electrode (RHE), and the conversion formula is as follows: E RHE =E Hg / HgO +0.2046 +0.059 pH Where E RHE E is the potential of the reference reversible hydrogen electrode, and 0.2046 is the standard electrode potential of the reference electrode Hg / HgO; Hg / HgO This is the actual voltage measured relative to the reference electrode. pH refers to the electrolyte during the electrode testing process, with a pH value of 14.

[0050] Table 1 summarizes the electrode preparation methods and overpotentials of Examples 1-7 and Comparative Examples 1-6.

[0051] ("—" indicates no value) Table 1 shows the hydrogen evolution tests (HER) conducted on the copper-cobalt bimetallic electrodes prepared in Examples 1, 2, 3, and 4 under different metal ratios. Specifically, in a three-electrode system using 1M KOH solution, Hg / HgO was used as the reference electrode, a 1cm×1cm platinum sheet as the counter electrode, and a 1cm×1cm catalyst electrode as the working electrode. The HER potential range was -0.2 V to -1.7 V (vs. Hg / HgO), and the scan rate was 5 mV / s. -1 Perform the test and plot the linear volt-ampere curve; Table 1 shows the oxygen evolution tests (OER) of the copper-cobalt bimetallic electrodes prepared in Examples 1, 2, 3, and 4 under different metal ratios. Specifically, in a three-electrode system of 1M KOH solution, Hg / HgO was used as the reference electrode, a 1cm×1cm platinum sheet as the counter electrode, and a 1cm×1cm catalyst electrode as the working electrode. The potential range for the OER test was 0V to 1.0V (vs. Hg / HgO), and the scan rate was 5 mV / s. -1 Perform the test and plot the linear volt-ampere curve; Table 1 shows the hydrogen evolution tests (HER) of the copper-cobalt bimetallic electrodes prepared in Examples 1, 5, 6, and 7 at different calcination temperatures. Specifically, in a three-electrode system using 1M KOH solution, Hg / HgO was used as the reference electrode, a 1cm×1cm platinum sheet as the counter electrode, and a 1cm×1cm catalyst electrode as the working electrode. The HER test potential range was -0.2 V to -1.7 V (vs. Hg / HgO), and the scan rate was 5 mV / s. -1 Perform the test and plot the linear volt-ampere curve; Table 1 shows the oxygen evolution tests (OER) of the copper-cobalt bimetallic electrodes prepared in Examples 1, 5, 6, and 7 at different calcination temperatures. Specifically, in a three-electrode system using 1M KOH solution, Hg / HgO was used as the reference electrode, a 1cm×1cm platinum sheet as the counter electrode, and a 1cm×1cm catalyst electrode as the working electrode. The potential range for the OER test was 0V to 1.0V (vs. Hg / HgO), and the scan rate was 5 mV / s. -1 Perform the test and plot the linear volt-ampere curve; As shown in Table 1, the overpotential of the copper-cobalt bimetallic electrode prepared with a copper-cobalt ratio of 3:7 is significantly lower than that prepared under other metal ratios; at a current density of 100 mA cm⁻¹ -2 When the hydrogen evolution overpotential is only 268 mV, it is superior to copper-cobalt bimetallic electrodes prepared under other copper-cobalt metal ratios, thus proving that the copper-cobalt bimetallic electrode has the best catalytic activity for the hydrogen evolution reaction of water electrolysis when the copper-cobalt metal ratio is 3:7.

[0052] As shown in Table 1, the overpotential of the copper-cobalt bimetallic electrode prepared with a copper-cobalt ratio of 3:7 is significantly lower than that prepared under other metal ratios; at a current density of 50 mA cm⁻¹ -2 When the oxygen evolution overpotential is only 346 mV, it is superior to copper-cobalt bimetallic electrodes prepared under other copper metal ratios, thus proving that the copper-cobalt bimetallic electrode has the best catalytic activity for the oxygen evolution reaction of water electrolysis when the copper-cobalt ratio is 3:7.

[0053] As shown in Table 1, the overpotential of the copper-cobalt bimetallic electrode prepared at a calcination temperature of 300℃ is significantly lower than that of electrodes prepared under other calcination temperature conditions; at a current density of 100 mA cm⁻¹... -2 At this temperature, the hydrogen evolution overpotential is only 268 mV, which is better than that of copper-cobalt bimetallic electrodes prepared under other calcination temperature conditions, thus proving that the copper-cobalt bimetallic electrode has the best catalytic activity for the hydrogen evolution reaction of water electrolysis at a calcination temperature of 300℃.

[0054] As shown in Table 1, the overpotential of the copper-cobalt bimetallic electrode prepared at a calcination temperature of 300℃ is significantly lower than that of electrodes prepared at other calcination temperatures; at a current density of 50 mA cm⁻¹... -2 At this temperature, the oxygen evolution overpotential is only 346 mV, which is better than that of copper-cobalt bimetallic electrodes prepared under other calcination temperature conditions, thus proving that the copper-cobalt bimetallic electrode has the best catalytic activity for the oxygen evolution reaction of water electrolysis at a calcination temperature of 300℃.

[0055] from Figure 3It can be seen that under the same conditions, the overpotential of the copper-cobalt bimetallic electrode is significantly lower than that of the electrodes prepared by other metals; when the current density is 100 mA cm -2 , its hydrogen evolution overpotential is only 268 mV, which is better than other electrodes, thereby proving that the copper-cobalt bimetallic electrode has excellent catalytic activity for water electrolysis hydrogen evolution reaction.

[0056] From Figure 4 it can be seen that under the same conditions, the overpotential of the copper-cobalt bimetallic electrode is significantly lower than that of the electrodes prepared by other metals; when the current density is 50 mA cm -2 , its oxygen evolution overpotential is only 346 mV, which is better than other electrodes, thereby proving that the copper-cobalt bimetallic electrode has excellent catalytic activity for water electrolysis oxygen evolution reaction.

[0057] From Figure 5 it can be seen that under the same conditions, the overpotential of the copper-cobalt bimetallic electrode B-Cu3Co7 / Cu-E / T-CF prepared after constant voltage etching of CF substrate is lower; when the current density is 100 mA cm -2 , its hydrogen evolution overpotential is only 268 mV, which is better than that of B-Cu3Co7 / T-CF electrode, thereby proving that the copper-cobalt bimetallic electrode prepared after constant voltage etching of CF has excellent catalytic activity for water electrolysis hydrogen evolution reaction.

[0058] From Figure 6 it can be seen that under the same conditions, the overpotential of the copper-cobalt bimetallic electrode B-Cu3Co7 / Cu-E / T-CF prepared after constant voltage etching of CF substrate is lower; when the current density is 50 mA cm -2 , its oxygen evolution overpotential is only 346 mV, which is better than that of B-Cu3Co7 / T-CF electrode, thereby proving that the copper-cobalt bimetallic electrode prepared after constant voltage etching of CF has excellent catalytic activity for water electrolysis oxygen evolution reaction.

[0059] From Figure 7 it can be seen that under the same conditions, the overpotential of the copper-cobalt bimetallic electrode B-Cu3Co7 / Cu-E / T-CF prepared after constant voltage etching of CF substrate is lower; when the current density is 100 mA cm -2 , its hydrogen evolution overpotential is only 268 mV, which is better than that of Cu3Co7 / Cu-E / T-CF electrode, thereby proving that the copper-cobalt bimetallic electrode prepared after constant voltage etching of CF has excellent catalytic activity for water electrolysis hydrogen evolution reaction.

[0060] From Figure 8It can be seen that, under the same conditions, the copper-cobalt bimetallic electrode B-Cu3Co7 / Cu-E / T-CF prepared after introducing boric acid has a lower overpotential; at a current density of 50 mA cm⁻¹ -2 At that time, its oxygen evolution overpotential was only 346mV, which is better than that of the B-Cu3Co7 / T-CF electrode, thus proving that the copper-cobalt bimetallic electrode prepared by introducing boric acid has excellent catalytic activity for the oxygen evolution reaction of water electrolysis.

[0061] Figure 9 and 10 At a current density of 50 mA cm⁻¹ -2 Stability tests were conducted on the copper-cobalt bimetallic electrode B-Cu3Co7 / Cu-E / T-CF. The results showed that after 100 h of testing, the electrode maintained stability at the HER end (…). Figure 9 ), OER end ( Figure 10 The potentials of all samples did not change significantly, indicating that the catalyst has excellent stability.

[0062] The three-dimensional copper-based doped copper-cobalt bimetallic electrode prepared in Example 1 was visualized using a scanning electron microscope (Quanta 400FEG, manufactured by FEI Corporation, USA). Figure 11 As can be seen from the results, the obtained three-dimensional copper-based doped copper-cobalt bimetallic electrode exhibits a dendritic structure composed of nanoparticles grown on nanowires.

[0063] The embodiments described above are merely preferred embodiments of the present invention, and not all feasible embodiments of the present invention. Any obvious modifications made by those skilled in the art without departing from the principles and spirit of the present invention should be considered to be included within the scope of protection of the claims of the present invention.

Claims

1. A method for preparing a copper-based electrode, characterized in that: S1: a copper substrate with a porosity of 80-90% is immersed in an HCl solution for 10-40 min, and then cleaned and dried to obtain a T-CF; S2: the treated copper substrate T-CF is subjected to electrochemical etching in an aqueous solution of one or both of KCl and NaCl by using a constant voltage method, and then cleaned and dried to obtain a Cu-E / T-CF; S3: a copper salt, a cobalt salt, a precursor of B, and a stabilizer are mixed in water to form a precursor cobalt-copper mixed solution, and then the precursor cobalt-copper mixed solution and the Cu-E / T-CF obtained after pretreatment are placed in a reaction kettle to perform a hydrothermal reaction; after the reaction, the product is cleaned and dried to obtain a precursor a; the copper-based electrode comprises a substrate, a copper-cobalt oxide, and a cobalt-boron compound catalyst; the copper-cobalt oxide and the cobalt-boron compound catalyst are attached to the substrate; the porosity of the substrate before tabletting is 93-98%, and the porosity of the substrate after tabletting is 80-90%. The concentration of HCl in step S1 is 0.5 mol / L-3 mol / L; the immersion treatment is ultrasonic immersion treatment, and then the product is cleaned with acetone and / or anhydrous ethanol, and then with deionized water, and then dried in an oven at 30-90°C to obtain the T-CF. In step S2, the concentration of the aqueous KCl and / or NaCl solution is 0.5 mol / L-2 mol / L; the constant voltage etching voltage ranges from-0.8 V to 0.7 V, and the constant voltage etching time is 2 min-30 min; the T-CF is used as a working electrode, and the distance between the working electrode and a counter electrode is 3 cm-8 cm. 5.A method for preparing a copper-based electrode according to claim 1, characterized in that: the cobalt salt in S3 is one or more of a cobalt carbonate, a cobalt sulfate, a cobalt chloride, a cobalt nitrate solution, and a cobalt acetate, and the concentration of the cobalt salt in water is 0.01 mol / L-5.0 mol / L; the copper salt in S3 is one or more of a copper sulfate, a copper acetate, a copper chloride, a copper nitrate, and a copper phosphate, and the concentration of the copper salt in water is 0.01 mol / L-1.5 mol / L; the hydrothermal reaction temperature in S3 is 70-190°C, and the hydrothermal time is 6 h-36 h; the stabilizer is one or more of a polyvinylpyrrolidone (PVP), urea, ammonia, and ethylenediamine, and the concentration of the stabilizer in water is 0.05 mol / L-1.0 mol / L; the precursor of B is H3BO3, and the concentration of H3BO3 in water is 0.05 mol / L-2.0 mol / L. 6.A method for preparing a copper-based electrode according to claim 1 or 2 or 5, characterized in that: in S3, the copper salt, the cobalt salt, the precursor of B, and the stabilizer are mixed in water to form a precursor cobalt-copper mixed solution under normal temperature conditions, and stirred for 20-60 min. ​ S4: the dried precursor a is calcined in a nitrogen atmosphere to obtain a copper-based electrode B-Cu x Co y / Cu-E / T-CF; ​ The copper cobalt oxide and cobalt boride compound catalyst is a nanostructure composed of nanoparticles and nanowires, the copper cobalt oxide presents a nanowire structure, composed of CuO, Co3O4 and CuCo2O4, containing etched CuO, the length of the nanowire is 170 nm-350 nm, the diameter of the nanowire is 0.005 μm-2 μm, the loading of the copper cobalt oxide on the substrate is 0.1 mg / cm 2 ~5.5 mg / cm 2 ; the cobalt boride compound presents a nanoparticle structure, the diameter of the nanoparticle is 0.05 μm-2 μm, the cobalt boride compound is CoB, the loading on the substrate is 0.1 mg / cm 2 ~ 1.5 mg / cm 2 , B-Cu x Co y The total loading of the copper cobalt oxide and cobalt boride compound on the substrate in the B-Cu 2 Co 2 / Cu-E / T-CF electrode is 1 mg / cm-6.5 mg / cm.

2. The method for preparing a copper-based electrode according to claim 1, characterized in that: The process for obtaining the copper substrate with a porosity of 80-90% in step S1 is as follows: a sheet-shaped copper substrate with a thickness of 0.5-1.5 mm and an area of 1.5-4.5 cm 2 is pressed on a tablet press at 0.3 MPa-3 MPa for 40 s ~ 120 s. ​ 3. The method of claim 1 or 2, wherein the copper-based electrode is prepared by: ​ ​ 4. The method for preparing a copper-based electrode according to claim 1 or 2, characterized in that: ​ ​ The thickness of the copper sheet before pressing is 0.5-1.5 mm, and the area is 1.5-4.5 cm 2 The volume of the KCl and / or NaCl aqueous solution is 150-250 mL. ​ ​ ​ ​ ​ ​ ​ ​ After the reaction, the reactor is cooled to room temperature, then washed with acetone or anhydrous ethanol, and then washed with ultrapure water, and then placed in a vacuum oven at 40-80℃ for drying for 6-15 h to obtain electrode a; The thickness of the tablet before pressing against the base is 0.5-1.5 mm, and the area is 1.5-4.5 cm 2 copper base; the volume of the precursor cobalt-copper mixed solution is 30-80 mL.

7. The method of claim 1, wherein the copper-based electrode is prepared by: The precursor a in S4 is calcined in a nitrogen atmosphere, and the heating rate from room temperature or the drying temperature in S3 to the calcination temperature is controlled to be 2-10℃ / min, the calcination temperature is 200-700℃, and the calcination time is 1-8 h.

8. The copper-based electrode prepared by the method of any one of claims 1-7.

9. The copper-based electrode prepared by the method of claim 8, wherein the copper-based electrode is used as an electrode for hydrogen evolution from water electrolysis, oxygen evolution from water electrolysis, hydrogen evolution from seawater electrolysis, oxygen evolution from seawater electrolysis, charging of both anode and cathode of metal-air battery, or electrode in fuel cell reaction under energy storage conditions. The substrate surface after etching in step S2 is distributed with a plurality of nanoparticles, and the loading amount of the nanoparticles is 0.05 mg / cm 2 0.35 mg / cm 2 The diameter of the nanoparticles is 0.005 μm to 2 μm; and the nanoparticles on the surface of the Cu-E / T-CF are CuO.

10. Use of the method for the production of a copper-based electrode according to claim 8 or 9 to produce a copper-based electrode, characterized in that: ​

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