A copper-based electrode and preparation and use thereof

Abstract

The present application relates to a kind of copper-based electrode and its preparation and application.The electrode preparation method includes: the pretreatment of substrate, by constant voltage method to copper substrate electrochemical etching reconfiguration without additional Cu source, copper cobalt transition metal oxide, boride catalyst growth, high-temperature calcination, and copper-based double-effect electrode is prepared.This structure shows excellent oxygen precipitation and hydrogen precipitation activity and stability in alkaline medium.The (integrated) electrode prepared in the application does not need to rely on current collector and additional binder, simplifies the preparation process and reduces the cost.The electrode can be used for electrolytic water hydrogen evolution electrode, electrolytic water oxygen evolution electrode, electrolytic seawater hydrogen evolution electrode, electrolytic seawater oxygen evolution electrode, metal-air battery charging cathode and anode or electrode in fuel cell reaction under energy storage conditions.

Description

Technical Field

[0001] This invention belongs to the field of water electrolysis, and particularly relates to a copper-based electrode and its preparation and application. Background Technology

[0002] With rapid economic development, energy demand is increasing daily, and the massive consumption of fossil fuels has exacerbated the greenhouse effect, causing severe damage to the global ecological environment. To effectively reduce dependence on fossil fuels, decrease pollution emissions, and curb environmental degradation, developing and promoting renewable energy has become an inevitable strategic choice for achieving sustainable development and carbon reduction goals. However, the development and utilization of renewable energy sources such as wind and solar power face bottlenecks due to their discontinuous and unstable nature. In contrast, hydrogen energy boasts high calorific value, is clean and environmentally friendly, has wide availability, diverse applications, and excellent storage and transportation characteristics. As a crucial component of the future energy system, hydrogen energy demonstrates enormous potential in transportation, industry, and power generation.

[0003] 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 best-performing industrial-grade water electrolysis catalysts still rely on precious 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-precious metal water electrolysis catalysts has become an important development trend. Among them, the oxide formed by cobalt (Co) and copper (Cu) has attracted widespread attention due to its excellent electronic conductivity and low cost. Multi-element synergy improves the hydrogen evolution reaction (HER) and oxygen evolution reaction (OER) activities of the catalyst and also enhances its stability. Wang et al. [Nano Letters, 2017, 17(12): 7989-7994.] developed the OER activity of CuCo2O4 particles, which is at 10 mA cm⁻¹. -2 At a current density of 20 mA cm⁻¹, it exhibited an overpotential of 327 mV, indicating that the copper-cobalt oxide is relatively stable, but its overpotential is still very high. Zheng et al. [European Journal of Inorganic Chemistry, 2018, (31): 3565-3569.] pointed out that CuCo₂O₄ nanoarrays are effective for the HER reaction at 20 mA cm⁻¹. -2 The overpotential is 227 mV. However, these cobalt-copper based composites and their derived transition metal oxide-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. In particular, during long-term electrolysis, the catalyst is prone to detachment from the electrode surface, thereby reducing its catalytic activity.

[0004] To address the aforementioned technical challenges, the present invention aims to provide a Cu-based electrode, its preparation, and its application. The invention first utilizes a constant voltage method to electrochemically etch a substrate, growing more defect sites and active groups on its surface. Simultaneously, nanoparticles grow on the etched substrate surface, increasing the loading area. Then, a metal oxide is loaded onto the surface using an H3BO3-assisted hydrothermal calcination method, thus preparing a copper-based electrode, B-Cu. x Co y / Cu-E / T-CF, wherein the loading of copper cobalt oxide is 0.6 mg / cm³. 2 ~ 3.5 mg / cm 2 The loading of copper cobalt boride was 0.1 mg / cm³. 2 ~ 1.5 mg / cm 2 .

[0005] Electrochemical etching of the substrate increases the substrate loading area. Simultaneously, the defect sites and active groups (such as -OH) generated on the copper substrate surface enhance the bonding ability between the catalyst and the substrate layer, making it less prone to detachment during testing and improving catalyst stability. Furthermore, B-Cu can be grown on the Cu-E / T-CF surface using boric acid-assisted hydrothermal etching after etching. x Co y The abundance of nanoparticles increases the loading area and the number of active sites, and by modulating the intrinsic electronic structure of the active material, the stability and catalytic activity of the catalyst are improved. This fabrication method, which couples electrochemical etching and reconstruction with chemical preparation techniques, enables the prepared electrode to possess both high HER and OER bifunctional activity and stability.

[0006] The electrode prepared by this invention does not require the addition of additional binders and current collectors, fundamentally optimizing the overall performance of the electrode; its unique through-type three-dimensional structure ensures full wetting of the electrolyte, significantly promoting the transport efficiency of reactants and products. Summary of the Invention

[0007] A copper-based self-supporting electrode is disclosed for fabrication and application. The electrode comprises a substrate, copper-cobalt oxide, and a cobalt-boron compound catalyst. The substrate layer has a thickness of 0.5-1.5 mm. The copper-cobalt oxide exhibits a nanowire structure, composed of CuO, Co3O4, and CuCo2O4. The nanowires have a length of 170 nm to 350 nm and a diameter of 0.005 μm to 2 μm. The loading of copper-cobalt oxide on the substrate is 0.1 mg / cm². 2 ~5.5mg / cm 2 The cobalt-boron compound exhibits a nanoparticle structure with a diameter ranging from 0.05 μm to 2 μm. The cobalt-boron compound is CoB, and its loading on the substrate is 0.1 mg / cm³. 2~ 1.5 mg / cm 2 B-Cu x Co y The / Cu-E / T-CF electrode contains CuO generated during etching, as well as copper-cobalt oxides and cobalt-boron compounds obtained after hydrothermal calcination, with a total loading of 1 mg / cm³ on the substrate. 2 ~6.5mg / cm 2 .

[0008] The method for preparing the three-dimensional porous electrode includes the following specific steps:

[0009] S1: A material with a thickness of 0.5-1.5 mm and an area of ​​1.5-4.5 cm². 2 The copper substrate is compressed on a tablet press at 0.3 MPa-3 MPa for 40-120 s (preferably 45-90 s), then placed 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, rinsed several times with acetone or anhydrous ethanol and ultrapure water, and then dried in a vacuum oven at 30℃-90℃ (40℃-90℃) for later use.

[0010] S2: The copper substrate to be treated is electrochemically etched in an aqueous solution of one or both of KCl and NaCl using a constant voltage method, denoted as Cu-E / T-CF. After etching, the substrate is washed with ultrapure solvents. The volume of the KCl and / or NaCl aqueous solution is 150-250 mL.

[0011] S3: Copper salt, cobalt salt, boric acid, etc., are mixed with stabilizer and added to deionized water. Under room temperature, the mixture is magnetically stirred 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. This solution is poured into a reaction vessel, and then the pretreated Cu-E / T-CF is added to the reaction vessel. The vessel is then placed in a vacuum oven for reaction. After the reaction is completed, the reaction vessel is removed and cooled. It is then rinsed several times with acetone or anhydrous ethanol and ultrapure water, and then dried in a vacuum oven at 40℃~80℃ for 6 h-15 h to obtain electrode a; the molar ratio of copper salt to cobalt salt is 0.1-10.

[0012] S4: 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 range of B is 5-15%, the molar percentage range of Cu is 15-55% (excluding the copper substrate, only the copper content of the catalyst layer), the molar percentage range of Co is 25-45%, and the molar percentage range of O is 30-60%. The content of B, Cu, and Co is estimated by subtracting the content of the element in the ICP from the amount added based on the hydrothermal analysis. The value of O is estimated by analysis and coordination based on XPS, XRD, etc.

[0013] All electrodes in this experiment were used in a three-electrode system with 1M KOH solution. Hg / HgO was used as the reference electrode, a 1cm x 1cm platinum sheet as the counter electrode, and a 1cm x 1cm catalyst electrode as the working electrode. The distance between the working and counter electrodes was 3 cm to 8 cm. The potential range for hydrogen evolution assay (HER) was -0.2 V to -1.7 V (vs. Hg / HgO), and the potential range for oxygen evolution assay (OER) was 0.0 V to 1.0 V (vs. Hg / HgO). The scan rate was 5 mV / s. -1 .

[0014] The porosity of the substrate before compression is 93-98%, and the porosity of the substrate after compression is 80-90%.

[0015] In step S1, the preferred ultrasonic treatment time is 35 min; the preferred drying temperature is 70℃.

[0016] In step S1, the HCl concentration is 0.5 mol / L-1.5 mol / L, preferably 0.8 mol / L-1.2 mol / L.

[0017] In step S2, the concentration of NaCl and / or KCl is 0.5 mol / L-2.0 mol / L, preferably 1.0 mol / L-1.5 mol / L;

[0018] In step S2, the constant voltage etching voltage range is -0.8 V to 0.7 V, the preferred duration is -0.3 V to 0.5 V, the constant voltage etching duration is 2 min to 30 min, and the preferred duration is 5 min to 20 min.

[0019] 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, and the concentration of the cobalt salt is 0.01 mol / L-5.0 mol / L, preferably 0.2 mol / L-1.5 mol / L;

[0020] 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;

[0021] 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.

[0022] 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;

[0023] In step S3, the precursor of B is H3BO3, with a concentration of 0.05 mol / L to 2.0 mol / L; preferably 0.15 mol / L to 0.55 mol / L.

[0024] 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.

[0025] 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.

[0026] 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.

[0027] The advantages of this invention compared to the prior art are:

[0028] The present invention provides a three-dimensional copper-based copper-cobalt bimetallic self-supporting electrode. The electrode is prepared by a three-step method of constant voltage etching / hydrothermal / calcination using copper foam as a substrate.

[0029] Because the preparation process uses constant voltage etching, hydrothermal method and calcination method, the entire synthesis steps are simple and convenient, and the raw materials are cheap and widely available, which can be used for large-scale production.

[0030] The three-dimensional copper-based copper-cobalt bimetallic electrode exhibits excellent catalytic activity (at a current density of 100 mA cm⁻¹). -2 The hydrogen evolution overpotential is 268 mV at a current density of 50 mA cm⁻¹. -2 The oxygen evolution overpotential was 346 mV, indicating that the three-dimensional copper-based copper-cobalt oxide electrode exhibits good electrocatalytic performance in hydrogen evolution and oxygen evolution reactions under alkaline conditions. The preparation process of this invention is relatively simple, and the raw materials are inexpensive and abundant, which is beneficial for improving the efficiency of hydrogen production through water electrolysis and promoting the development of hydrogen energy.

[0031] This invention relates to a copper-based dual-effect electrode, its preparation, and its application. The electrode preparation method includes: substrate pretreatment, electrochemical etching and reconstruction of the copper substrate using a constant voltage method without adding an additional Cu source, growth of a copper-cobalt transition metal oxide and boride catalyst, and high-temperature calcination to obtain the copper-based dual-effect electrode. Through electrochemical etching and reconstruction, an activation layer is generated on the substrate surface. The active groups and defects on this surface can form stronger chemical bonds with the catalyst layer, further improving adhesion and thus enhancing catalyst stability. The CuCo bimetallic layer exhibits a synergistic effect, promoting charge transfer during water electrolysis; therefore, the electrode possesses dual-effect high electrocatalytic activity and high stability. xThe introduction of a small amount of boron (B) onto the surface can effectively regulate the surface electronic structure and microstructure of the catalyst, increasing the exposure of active sites and enhancing synergistic effects through the amorphous / crystalline phase interface. This structure exhibits excellent oxygen and hydrogen evolution activity and stability in alkaline media. The (integrated) electrode prepared by this invention does not require current collectors or additional binders, simplifying the preparation process and reducing costs. This electrode can be used to prepare hydrogen evolution electrodes for water electrolysis, oxygen evolution electrodes for water electrolysis, hydrogen evolution electrodes for seawater electrolysis, oxygen evolution electrodes for seawater electrolysis, electrodes for the charging and discharging electrodes of metal-air batteries or for fuel cell reactions under energy storage conditions, and anode electrodes for carbon dioxide electroreduction reactions. Attached Figure Description

[0032] Figure 1 The hydrogen evolution test (HER) of the copper-cobalt bimetallic electrode prepared in Example 1 was performed in a three-electrode system of 1M KOH solution, using Hg / HgO as the reference electrode, a platinum sheet with dimensions of 1 cm × 1 cm as the counter electrode, and a catalyst electrode with dimensions of 1 cm × 1 cm as the working electrode. The potential range for the HER test 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.

[0033] Figure 2 The oxygen evolution test was performed on the copper-cobalt bimetallic electrode prepared in Example 1. Specifically, in a three-electrode system of 1M KOH solution, Hg / HgO was used as the reference electrode, a platinum sheet with dimensions of 1 cm × 1 cm was used as the counter electrode, and a catalyst electrode with dimensions of 1 cm × 1 cm was used as the working electrode. The potential range for the oxygen evolution test (OER) was 0 V to 1.0 V (vs. Hg / HgO), and the scan rate was 5 mV s. -1 Perform the test and plot the linear volt-ampere curve.

[0034] Figure 3 The hydrogen evolution test (HER) of the copper-cobalt bimetallic electrode prepared in Example 1 was performed in a three-electrode system with 1M KOH solution. Hg / HgO was used as the reference electrode, a 1cm x 1cm platinum sheet as the counter electrode, and a 1cm x 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.

[0035] Figure 4The oxygen evolution test (OER) of the copper-cobalt bimetallic electrode prepared in Example 1 was compared with those of Comparative Examples 1, 2, 3, and 4. Specifically, in a three-electrode system of 1M KOH solution, Hg / HgO was used as the reference electrode, a platinum sheet (1 cm × 1 cm) as the counter electrode, and a catalyst electrode (1 cm × 1 cm) as the working electrode. The potential range for the OER test was 0 V to 1.0 V (vs. Hg / HgO), and the scan rate was 5 mV / s. -1 Perform the test and plot the linear volt-ampere curve.

[0036] Figure 5 The hydrogen evolution test (HER) of the copper-cobalt bimetallic electrode prepared in Example 1 and Comparative Example 5 was performed in a three-electrode system of 1M KOH solution, with Hg / HgO as the reference electrode, a platinum sheet with dimensions of 1 cm × 1 cm as the counter electrode, and a catalyst electrode with dimensions of 1 cm × 1 cm as the working electrode. The potential range for the HER test 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.

[0037] Figure 6 The oxygen evolution test (OER) of the copper-cobalt bimetallic electrode prepared in Example 1 and Comparative Example 5 was performed in a three-electrode system of 1M KOH solution, with Hg / HgO as the reference electrode, a platinum sheet with dimensions of 1 cm × 1 cm as the counter electrode, and a catalyst electrode with dimensions of 1 cm × 1 cm as the working electrode. The potential range for the OER test was 0 V to 1.0 V (vs. Hg / HgO), and the scan rate was 5 mV s. -1 Perform the test and plot the linear volt-ampere curve.

[0038] Figure 7 The hydrogen evolution test (HER) of the copper-cobalt bimetallic electrode prepared in Example 1 and Comparative Example 6 was performed in a three-electrode system of 1M KOH solution, using Hg / HgO as the reference electrode, a platinum sheet with dimensions of 1 cm × 1 cm as the counter electrode, and a catalyst electrode with dimensions of 1 cm × 1 cm as the working electrode. The potential range for the HER test 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.

[0039] Figure 8The oxygen evolution test (OER) of the copper-cobalt bimetallic electrode prepared in Example 1 and Comparative Example 6 was performed in a three-electrode system of 1M KOH solution, with Hg / HgO as the reference electrode, a platinum sheet with dimensions of 1 cm × 1 cm as the counter electrode, and a catalyst electrode with dimensions of 1 cm × 1 cm as the working electrode. The potential range for the OER test was 0 V to 1.0 V (vs. Hg / HgO), and the scan rate was 5 mV s. -1 Perform the test and plot the linear volt-ampere curve.

[0040] Figure 9 The copper-cobalt bimetallic electrode prepared in Example 1 had a current density of 50 mA cm⁻¹ in 1M KOH solution. -2 The 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.

[0041] 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.

[0042] 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

[0043] 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.

[0044] 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.

[0045] The present invention will be further described below:

[0046] 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:

[0047] 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.

[0048] 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, and the concentration of boric acid is 0.05-2.0 mol·L⁻¹. -1 The concentration of urea is 0.05-1 mol·L⁻¹ -1 The concentration of polyvinylpyrrolidone (PVP) is 0.05-1 mol·L⁻¹. -1 ;

[0049] 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) was mixed with deionized water and magnetically stirred for 20-60 min at room temperature to form a cobalt-copper precursor solution. This solution was poured into a reaction vessel, followed by Cu-E / T-CF, and then placed in a vacuum oven for reaction. After the reaction, the reaction vessel was removed and cooled, then rinsed repeatedly with acetone or anhydrous ethanol and ultrapure water, and finally dried in a 70℃ vacuum oven for 6-15 h to obtain electrode a; the concentration of copper salt was 0.01 mol·L⁻¹. -1 -1.5 mol·L -1 The preferred concentration is 0.2 mol·L⁻¹. -1 -1.0 mol·L -1 The concentration of cobalt salt is 0.01 mol·L⁻¹. -1 -5.0 mol·L -1 The preferred concentration is 0.2 mol·L⁻¹. -1 -1.5 mol·L -1 The hydrothermal temperature is 70℃~190℃, preferably 100℃~160℃, and the heating time is 6~36 h, preferably 12-21 h.

[0050] 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 ranges from 5-15%, the molar percentage of Cu ranges from 15-55% (excluding the copper substrate, only the copper content of the catalyst layer), the molar percentage of Co ranges from 25-45%, and the molar percentage of O ranges from 30-60%.

[0051] Example 1

[0052] A material with a thickness of 1 mm and an area of ​​3 cm² 2Flake-shaped copper foam (CF) was compressed at 1 MPa for 45 s along the perpendicular thickness direction on a tablet press, then ultrasonically treated in 1 mol / L HCl solution for 30 min. After rinsing with acetone and deionized water, it was dried in an oven at 70℃ for 10 h and designated as T-CF. The porosity of CF was 95%, and that of T-CF was 85%. T-CF was used as the working electrode in a 200 mL solution 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 counter electrode surfaces were positioned opposite each other at a distance of 4 cm, and a constant voltage of 0.1 V was applied for 15 min. After etching, it was rinsed with deionized water and dried in an oven at 70℃ for 24 h, designated as 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.

[0053] 50 mL of solutions containing 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) were added to water and mixed, and stirred for 30 min to form a copper-cobalt precursor solution.

[0054] 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:

[0055] Precursor a was placed in a tube furnace and calcined under nitrogen protection at 300°C for 2 hours to obtain electrode B-Cu3Co7 / Cu-E / T-CF.

[0056] T-CF indicates that the substrate CF has been pressed into a tablet, Cu-E / T-CF indicates that the substrate T-CF has been electrochemically etched, and B-Cu3Co7 / Cu-E / T-CF indicates the electrode obtained after hydrothermal calcination of Cu-E / T-CF. The numbers indicate the concentration of Cu added in water: 0.03 mol / L and Co: 0.07 mol / L. B indicates the addition of boric acid.

[0057] The electrode comprises a substrate, copper-cobalt oxide, and a cobalt-boron compound catalyst, the copper-cobalt oxide and the cobalt-boron compound catalyst being attached to the substrate; the copper-cobalt oxide exhibits a nanowire structure, composed of CuO, Co3O4, and CuCo2O4, including CuO generated by etching, the nanowires having a length of 210 nm to 350 nm and a diameter of 0.01 μm to 1 μm, and the loading of copper-cobalt oxide on the substrate being 5.0 mg / cm². 2 (Including CuO generated after etching), the cobalt-boron compound exhibits a nanoparticle structure with a diameter ranging from 0.05 μm to 2 μm. The cobalt-boron compound is CoB, and its loading on the substrate is 1.0 mg / cm³. 2 The total loading of copper-cobalt oxides and cobalt-boron compounds on the substrate in the B-Cu3Co7 / Cu-E / T-CF electrode is 6.0 mg / cm³. 2 The above nanostructures were obtained through SEM images.

[0058] Example 2

[0059] 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%.

[0060] 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.

[0061] 50 mL of solutions containing 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) were added to water and mixed, and stirred for 30 min to form a copper-cobalt precursor solution.

[0062] The precursor copper-cobalt mixed solution and the pretreated Cu-E / T-CF were placed in a reaction vessel and reacted in a vacuum oven at 100℃ for 18 h. After the reaction was completed, the reaction vessel 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.

[0063] Precursor a was placed in a tube furnace and calcined under nitrogen protection at 300°C for 2 hours to obtain electrode B-Cu7Co3 / Cu-E / T-CF.

[0064] T-CF indicates that the substrate CF has been pressed into a tablet, Cu-E / T-CF indicates that the substrate T-CF has been electrochemically etched, and B-Cu7Co3 / Cu-E / T-CF indicates that the electrode is obtained after hydrothermal calcination of the substrate Cu-E / T-CF. The numbers indicate the concentration of Cu added in water: 0.07 mol / L and Co: 0.03 mol / L. B indicates that boric acid has been added.

[0065] The electrode comprises a substrate, copper-cobalt oxide, and a cobalt-boron compound catalyst, which are attached to the substrate. The copper-cobalt oxide exhibits a nanowire structure, composed of CuO, Co3O4, and CuCo2O4 (including CuO generated by etching). The nanowires have a length of 170 nm to 320 nm and a diameter of 0.01 μm to 0.95 μm. The loading of copper-cobalt oxide on the substrate is 4.1 mg / cm². 2 (Including CuO generated after etching), the cobalt-boron compound exhibits a nanoparticle structure with a diameter ranging from 0.25 μm to 2 μm. The cobalt-boron compound is CoB, and its loading on the substrate is 0.8 mg / cm³. 2 The total loading of copper-cobalt oxides and cobalt-boron compounds on the substrate in the B-Cu7Co3 / Cu-E / T-CF electrode was 4.9 mg / cm³. 2 The above nanostructures were obtained through SEM images.

[0066] Example 3

[0067] 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%.

[0068] 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.

[0069] 50 mL of solutions containing 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) were added to water and mixed, and stirred for 30 min to form a copper-cobalt precursor solution.

[0070] 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:

[0071] Precursor a was placed in a tube furnace and calcined under nitrogen protection at 300°C for 2 hours to obtain electrode B-Cu5Co5 / Cu-E / T-CF.

[0072] T-CF indicates that the substrate CF has been pressed into a tablet, Cu-E / T-CF indicates that the substrate T-CF has been electrochemically etched, and B-Cu5Co5 / Cu-E / T-CF indicates that the electrode is obtained after hydrothermal calcination of the substrate Cu-E / T-CF. The numbers indicate the concentration of Cu added in water: 0.05 mol / L and Co: 0.05 mol / L. B indicates that boric acid has been added.

[0073] The electrode comprises a substrate, copper-cobalt oxide, and a cobalt-boron compound catalyst, the copper-cobalt oxide and the cobalt-boron compound catalyst being attached to the substrate; the copper-cobalt oxide exhibits a nanowire structure, composed of CuO, Co3O4, and CuCo2O4 (including CuO generated by etching), with nanowire lengths ranging from 210 nm to 340 nm and nanowire diameters from 0.11 μm to 1 μm, and a copper-cobalt oxide loading of 4.3 mg / cm² on the substrate. 2(Including CuO generated after etching), the cobalt-boron compound exhibits a nanoparticle structure with a diameter ranging from 0.05 μm to 1.9 μm. The cobalt-boron compound is CoB, and its loading on the substrate is 0.9 mg / cm³. 2 The 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.

[0074] Example 4

[0075] 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%.

[0076] 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.

[0077] 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.

[0078] 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:

[0079] 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.

[0080] T-CF indicates that the substrate CF has been pressed into a tablet, Cu-E / T-CF indicates that the substrate T-CF has been electrochemically etched, and B-Cu1Co9 / Cu-E / T-CF indicates that the electrode is obtained after hydrothermal calcination of the substrate Cu-E / T-CF. The numbers indicate the concentration of Cu added in water: 0.01 mol / L and Co: 0.09 mol / L. B indicates that boric acid has been added.

[0081] The electrode comprises a substrate, copper-cobalt oxide, and a cobalt-boron compound catalyst, the copper-cobalt oxide and the cobalt-boron compound catalyst being attached to the substrate; the copper-cobalt oxide exhibits a nanowire structure, composed of CuO, Co3O4, and CuCo2O4 (including CuO generated by etching), with nanowire lengths ranging from 230 nm to 340 nm and nanowire diameters from 0.01 μm to 0.95 μm, and the copper-cobalt oxide loading on the substrate is 4.5 mg / cm². 2 (Including CuO generated after etching), the cobalt-boron compound exhibits a nanoparticle structure with a diameter ranging from 0.45 μm to 2 μm. The cobalt-boron compound is CoB, and its loading on the substrate is 1.1 mg / cm³. 2 The total loading of copper-cobalt oxides and cobalt-boron compounds on the substrate in the B-Cu1Co9 / Cu-E / T-CF electrode was 5.6 mg / cm³. 2 The above nanostructures were obtained through SEM images.

[0082] Example 5

[0083] 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%.

[0084] 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.

[0085] 50 mL of solutions containing 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) were added to water and mixed, and stirred for 30 min to form a copper-cobalt precursor solution.

[0086] 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:

[0087] Precursor a was placed in a tube furnace and calcined under nitrogen protection at 200°C for 2 hours to obtain electrode B-Cu3Co7-200 / Cu-E / T-CF.

[0088] T-CF indicates that the substrate CF has been pressed into a tablet, Cu-E / T-CF indicates that the substrate T-CF has been electrochemically etched, and B-Cu3Co7-200 / Cu-E / T-CF indicates the electrode obtained after hydrothermal calcination of Cu-E / T-CF. The numbers indicate the concentration of Cu added in water: 0.03 mol / L and Co: 0.07 mol / L. B indicates the addition of boric acid, and 200 is the calcination temperature.

[0089] The electrode comprises a substrate, copper-cobalt oxide, and a cobalt-boron compound catalyst, which are attached to the substrate. The copper-cobalt oxide exhibits a nanowire structure, composed of CuO, Co3O4, and CuCo2O4 (including CuO generated by etching). The nanowires have a length of 170 nm to 300 nm and a diameter of 0.31 μm to 1 μm. The loading of copper-cobalt oxide on the substrate is 4.2 mg / cm². 2(Including CuO generated after etching), the cobalt-boron compound exhibits a nanoparticle structure with a diameter ranging from 0.55 μm to 2 μm. The cobalt-boron compound is CoB, and its loading on the substrate is 0.9 mg / cm³. 2 The total loading of copper-cobalt oxides and cobalt-boron compounds on the substrate in the B-Cu3Co7-200 / Cu-E / T-CF electrode is 5.1 mg / cm³. 2 The above nanostructures were obtained through SEM images.

[0090] Example 6

[0091] 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%.

[0092] 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.

[0093] 50 mL of solutions containing 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) were added to water and mixed, and stirred for 30 min to form a precursor solution.

[0094] 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:

[0095] Precursor a was placed in a tube furnace and calcined under nitrogen protection at 400°C for 2 hours to obtain electrode B-Cu3Co7-400 / Cu-E / T-CF.

[0096] T-CF indicates that the substrate CF has been pressed into a tablet, Cu-E / T-CF indicates that the substrate T-CF has been electrochemically etched, and B-Cu3Co7-400 / Cu-E / T-CF indicates the electrode obtained after hydrothermal calcination of Cu-E / T-CF. The numbers indicate the concentration of Cu added in water: 0.03 mol / L and Co: 0.07 mol / L. B indicates the addition of boric acid, and 400 is the calcination temperature.

[0097] The electrode comprises a substrate, copper-cobalt oxide, and a cobalt-boron compound catalyst, the copper-cobalt oxide and the cobalt-boron compound catalyst being attached to the substrate; the copper-cobalt oxide exhibits a nanowire structure, composed of CuO, Co3O4, and CuCo2O4 (including CuO generated by etching), with nanowire lengths ranging from 170 nm to 340 nm and nanowire diameters ranging from 0.01 μm to 0.9 μm, and the loading of copper-cobalt oxide on the substrate being 5.0 mg / cm². 2 (Including CuO generated after etching), the cobalt-boron compound exhibits a nanoparticle structure with a diameter ranging from 0.35 μm to 2 μm. The cobalt-boron compound is CoB, and its loading on the substrate is 0.8 mg / cm³. 2 The total loading of copper-cobalt oxides and cobalt-boron compounds on the substrate in the B-Cu3Co7-400 / Cu-E / T-CF electrode is 5.8 mg / cm³. 2 The above nanostructures were obtained through SEM images.

[0098] Example 7

[0099] 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%.

[0100] 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.

[0101] 50 mL of solutions containing 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) were added to water and mixed, and stirred for 30 min to form a precursor solution.

[0102] 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:

[0103] Precursor a was placed in a tube furnace and calcined under nitrogen protection at 500°C for 2 hours to obtain electrode B-Cu3Co7-500 / Cu-E / T-CF.

[0104] T-CF indicates that the substrate CF has been pressed into a tablet, Cu-E / T-CF indicates that the substrate T-CF has been electrochemically etched, and B-Cu3Co7-500 / Cu-E / T-CF indicates the electrode obtained after hydrothermal calcination of Cu-E / T-CF. The numbers indicate the concentration of Cu added in water: 0.03 mol / L and Co: 0.07 mol / L. B indicates the addition of boric acid, and 500 is the calcination temperature.

[0105] The electrode comprises a substrate, copper-cobalt oxide, and a cobalt-boron compound catalyst, the copper-cobalt oxide and the cobalt-boron compound catalyst being attached to the substrate; the copper-cobalt oxide exhibits a nanowire structure, composed of CuO, Co3O4, and CuCo2O4 (including CuO generated by etching), with nanowire lengths ranging from 190 nm to 320 nm and nanowire diameters from 0.35 μm to 1 μm, and the copper-cobalt oxide loading on the substrate is 4.8 mg / cm². 2(Including CuO generated after etching), the cobalt-boron compound exhibits a nanoparticle structure with a diameter ranging from 0.65 μm to 2 μm. The cobalt-boron compound is CoB, and its loading on the substrate is 0.7 mg / cm³. 2 The total loading of copper-cobalt oxides and cobalt-boron compounds on the substrate in the B-Cu3Co7-500 / Cu-E / T-CF electrode is 5.5 mg / cm³. 2 The above nanostructures were obtained through SEM images.

[0106] Comparative Example 1

[0107] The preparation method of T-CF is the same as that of T-CF in Example 1.

[0108] Comparative Example 2

[0109] The preparation method of Cu-E / T-CF is the same as that of Cu-E / T-CF in Example 1.

[0110] Comparative Example 3

[0111] 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%.

[0112] T-CF was used as the working electrode in a 200 mL aqueous solution 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 positioned opposite each other at a distance of 4 cm, and a constant voltage of 0.1 V was applied for 15 min. After etching, the electrode was rinsed with deionized water and dried in an oven at 70 °C for 24 h. This result was denoted as Cu-E / T-CF, and its loading was 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.

[0113] 50 mL of solutions containing 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) were added to water and mixed, and stirred for 30 min to form a precursor solution.

[0114] The precursor solution and pretreated Cu-E / T-CF were placed in a reaction vessel and reacted in a vacuum oven at 100℃ for 18 h. After the reaction, the reaction vessel was removed and cooled to room temperature. The copper foam was then rinsed with acetone and deionized water sequentially, and placed in a 60℃ oven for 10 h to obtain precursor a.

[0115] Precursor a was placed in a tube furnace and calcined under nitrogen protection at 300°C for 2 hours to obtain electrode B-Cu3 / Cu-E / T-CF.

[0116] T-CF indicates that the substrate CF has been pressed into a tablet, Cu-E / T-CF indicates that the substrate T-CF has been electrochemically etched, and B-Cu3 / Cu-E / T-CF indicates the electrode obtained after hydrothermal calcination of Cu-E / T-CF. The numbers indicate the concentration of Cu added in water: 0.03 mol / L, and B indicates the addition of boric acid.

[0117] The electrode comprises a substrate and a copper oxide catalyst attached to the substrate. The copper oxide (CuO) is in the form of nanoparticles. The total loading of CuO generated during etching and from the copper oxide after hydrothermal calcination on the substrate in the B-Cu3 / Cu-E / T-CF electrode is 1.4 mg / cm³. 2 The nanoparticles have diameters ranging from 1.1 μm to 2 μm, and the above nanostructures were obtained using SEM images.

[0118] Comparative Example 4

[0119] 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%.

[0120] T-CF was used as the working electrode in a 200 mL aqueous solution 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 positioned opposite each other at a distance of 4 cm, and a constant voltage of 0.1 V was applied for 15 min. After etching, the electrode was rinsed with deionized water and dried in an oven at 70 °C for 24 h. This result was denoted as Cu-E / T-CF, and its loading was 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.

[0121] Mix 50 mL of 0.07 mol / L CoCl2·6H2O, 0.2 mol / L boric acid, 0.2 mol / L urea, and 0.1 mol / L polyvinylpyrrolidone (PVP) to form a precursor solution by stirring for 30 min.

[0122] The precursor solution and pretreated Cu-E / T-CF were placed in a reaction vessel and reacted in a vacuum oven at 100℃ for 18 h. After the reaction, the reaction vessel was removed and cooled to room temperature. The copper foam was then rinsed with acetone and deionized water sequentially, and placed in a 60℃ oven for 10 h to obtain precursor a.

[0123] Precursor a was placed in a tube furnace and calcined under nitrogen protection at 300°C for 2 hours to obtain electrode B-Co7 / Cu-E / T-CF.

[0124] T-CF indicates that the substrate CF has been pressed into a tablet, Cu-E / T-CF indicates that the substrate T-CF has been electrochemically etched, and B-Co7 / Cu-E / T-CF indicates the electrode obtained after hydrothermal calcination of Cu-E / T-CF. The numbers indicate the concentration of Co added in water: 0.07 mol / L, and B indicates the addition of boric acid.

[0125] The addition of cobalt and copper substrates participates in the reaction, resulting in the formation of copper-cobalt oxide in the reactants. The electrode comprises a substrate, copper-cobalt oxide, and a cobalt-boron compound catalyst, which are attached to the substrate. The copper-cobalt oxide exhibits a nanowire structure, composed of CuO, Co3O4, and CuCo2O4 (including CuO generated by etching). The nanowires have a length of 170 nm to 270 nm and a diameter of 0.41 μm to 0.9 μm. The Co3O4 loading on the substrate is 1.5 mg / cm³. 2 The cobalt-boron compound exhibits a nanoparticle structure with a diameter ranging from 0.25 μm to 2 μm. The cobalt-boron compound is CoB, and its loading on the substrate is 0.7 mg / cm³. 2 The total loading of copper-cobalt oxides and cobalt-boron compounds on the substrate in the B-Co7 / Cu-E / T-CF electrode was 2.45 mg / cm³. 2 The above nanostructures were obtained through SEM images.

[0126] Comparative Example 5

[0127] A material with a thickness of 1 mm and an area of ​​3 cm² 2Flake-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%.

[0128] 50 mL of solutions containing 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) were added to water and mixed, and stirred for 30 min to form a precursor solution.

[0129] The precursor solution and pretreated T-CF were placed in a reaction vessel and reacted in a vacuum oven at 100°C for 18 h. After the reaction, the reaction vessel was removed and cooled. The copper foam was then rinsed with acetone and deionized water sequentially, and placed in a 60°C oven for 10 h to obtain precursor a.

[0130] Precursor a was placed in a tube furnace and calcined under nitrogen protection at 300°C for 2 hours to obtain electrode B-Cu3Co7 / T-CF.

[0131] T-CF indicates that the substrate CF has been compressed into a tablet, and B-Cu3Co7 / T-CF indicates the electrode obtained after hydrothermal calcination of T-CF. The numbers indicate the concentration of Cu 0.03 mol / L and Co 0.07 mol / L added to the water, and B indicates the addition of boric acid.

[0132] The electrode comprises a substrate, copper-cobalt oxide, and a cobalt-boron compound catalyst, which are attached to the substrate. The copper-cobalt oxide exhibits a nanowire structure, composed of CuO, Co3O4, and CuCo2O4 (including CuO generated by etching). The nanowires have a length of 170 nm to 330 nm and a diameter of 0.21 μm to 1 μm. The loading of copper-cobalt oxide on the substrate is 4.5 mg / cm². 2 (Including CuO generated after etching), the cobalt-boron compound exhibits a nanoparticle structure with a diameter ranging from 0.25 μm to 2 μm. The cobalt-boron compound is CoB, and its loading on the substrate is 1 mg / cm³. 2 The total loading of copper-cobalt oxides and cobalt-boron compounds on the substrate in the B-Cu3Co7 / T-CF electrode was 5.5 mg / cm³. 2 The above nanostructures were obtained through SEM images.

[0133] Comparative Example 6

[0134] 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%.

[0135] T-CF was used as the working electrode in a 200 mL aqueous solution 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 positioned opposite each other at a distance of 4 cm, and a constant voltage of 0.1 V was applied for 15 min. After etching, the electrode was rinsed with deionized water and dried in an oven at 70 °C for 24 h. This result was denoted as Cu-E / T-CF, and its loading was 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.

[0136] 50 mL of solutions containing 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) were added to water and mixed, and stirred for 30 min to form a precursor solution.

[0137] The precursor solution and pretreated Cu-E / T-CF were placed in a reaction vessel and reacted in a vacuum oven at 100℃ for 18 h. After the reaction, the reaction vessel was removed and cooled to room temperature. The copper foam was then rinsed with acetone and deionized water sequentially, and placed in a 60℃ oven for 10 h to obtain precursor a.

[0138] Precursor a was placed in a tube furnace and calcined under nitrogen protection at 300°C for 2 hours to obtain electrode Cu3Co7 / Cu-E / T-CF.

[0139] T-CF indicates that the substrate CF has been pressed into a tablet, Cu-E / T-CF indicates that the substrate T-CF has been electrochemically etched, and Cu3Co7 / Cu-E / T-CF indicates the electrode obtained after hydrothermal calcination of Cu-E / T-CF. The numbers indicate the concentration of Cu added in water: 0.03 mol / L and Co 0.07 mol / L.

[0140] The electrode comprises a substrate and a copper-cobalt oxide catalyst, the copper-cobalt oxide catalyst being attached to the substrate; the copper-cobalt oxide exhibits a nanowire structure, composed of CuO, Co3O4, and CuCo2O4 (including CuO generated by etching), with nanowire lengths ranging from 170 nm to 310 nm and nanowire diameters from 0.21 μm to 1 μm, and a copper-cobalt oxide loading of 5.1 mg / cm² on the substrate. 2 (Including CuO generated after etching), the total loading of copper-cobalt oxide on the substrate in the Cu3Co7 / Cu-E / T-CF electrode is 5.1 mg / cm³. 2 The above nanostructures were obtained through SEM images.

[0141] Linear sweep voltammetry (LSV) is an important electrochemical analysis technique that studies the redox behavior of substances by applying a linearly varying voltage and measuring the response current. The horizontal axis of the LSV curve represents potential, and the vertical axis represents current; it can be used to compare the onset potential and current density of different catalysts. In the fields of 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, indicating that OER and HER have lower energy consumption. In this experiment, a three-electrode system using 1M KOH solution was employed, with Hg / HgO as the reference electrode, a 1cm x 1cm platinum sheet as the counter electrode, and the electrodes prepared in the above examples or comparative examples as the working electrodes. The potential range for oxygen evolution test (OER) was 0V to 1.0V (vs. Hg / HgO), and the potential range for hydrogen evolution test (HER) was -0.2V to -1.6V (vs. Hg / HgO), with a scan rate of 5 mV / s. -1 Conduct the test.

[0142] All test potentials are converted using a reversible hydrogen electrode (RHE), and the conversion formula is as follows:

[0143] E RHE =E Hg / HgO +0.2046 +0.059 pH

[0144] 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.

[0145] Table 1 summarizes the electrode preparation methods and overpotentials of Examples 1-7 and Comparative Examples 1-6.

[0146]

[0147] ("—" indicates no value)

[0148] 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;

[0149] 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;

[0150] 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;

[0151] 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;

[0152] 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.

[0153] 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.

[0154] 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℃.

[0155] 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℃.

[0156] from Figure 3 It can be seen that, under the same conditions, the overpotential of the copper-cobalt bimetallic electrode is significantly lower than that of electrodes made of other metals; at a current density of 100 mA cm⁻¹ -2 At that time, its hydrogen evolution overpotential was only 268 mV, which is better than other electrodes, thus proving that the copper-cobalt bimetallic electrode has excellent catalytic activity for the hydrogen evolution reaction of water electrolysis.

[0157] 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 electrodes made of other metals; at a current density of 50 mA cm⁻¹ -2At that time, its oxygen evolution overpotential was only 346 mV, which is better than other electrodes, thus proving that the copper-cobalt bimetallic electrode has excellent catalytic activity for the oxygen evolution reaction of water electrolysis.

[0158] from Figure 5 It can be seen that, under the same conditions, the copper-cobalt bimetallic electrode B-Cu3Co7 / Cu-E / T-CF prepared after constant voltage etching of the CF substrate has a lower overpotential; at a current density of 100 mA cm⁻¹ -2 At that time, its hydrogen evolution overpotential was only 268 mV, which is better than that of the B-Cu3Co7 / T-CF electrode, thus proving that the copper-cobalt bimetallic electrode prepared by constant voltage etching of CF has excellent catalytic activity for the hydrogen evolution reaction of water electrolysis.

[0159] from Figure 6 It can be seen that, under the same conditions, the copper-cobalt bimetallic electrode B-Cu3Co7 / Cu-E / T-CF prepared after constant voltage etching of the CF substrate has a lower overpotential; at a current density of 50 mA cm⁻¹ -2 At that time, its oxygen evolution overpotential was only 346 mV, which was better than that of the B-Cu3Co7 / T-CF electrode, thus proving that the copper-cobalt bimetallic electrode prepared by constant voltage etching of CF has excellent catalytic activity for the oxygen evolution reaction of water electrolysis.

[0160] from Figure 7 It 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 100 mA cm⁻¹ -2 At that time, its hydrogen evolution overpotential was only 268 mV, which is better than that of Cu3Co7 / Cu-E / T-CF electrode, thus proving that the copper-cobalt bimetallic electrode prepared by introducing boric acid has excellent catalytic activity for the hydrogen evolution reaction of water electrolysis.

[0161] from Figure 8 It 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 was 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.

[0162] Figure 9 and 10 At a current density of 50 mA cm⁻¹ -2Stability 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.

[0163] 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.

[0164] 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 catalysts are nanostructures 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 nanowires is 170 nm-350 nm, the diameter of the nanowires 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 nanoparticles 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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