Carbon-modified foamy copper electrode, preparation method and application

Abstract

The invention belongs to the technical field of environmental engineering, and particularly relates to a carbon-modified foamy copper electrode, a preparation method and application. The preparation method comprises the following steps: adding pretreated clean foamy copper into a solution consisting of sodium hydroxide and ammonium persulfate, and oxidizing to obtain a Cu (OH) 2-coated CF electrode; putting the obtained electrode into a tubular furnace for air atmosphere annealing to obtain a CuxO atCF (x = 1-2) nanorod array electrode; and immersing the CuxO-coated CF nanorod array electrode into an ethanol solution dispersed by Naifon, PTFE and carboxylated carbon nanotubes, and then drying the CuxO-coated CF nanorod array electrode in a drying oven to obtain the carbon-modified foamy copper electrode (PTFE / CNTs-COOH / CuxO-coated CF electrode). The prepared carbon-modified foamy copper electrode can reduce oxygen to generate hydrogen peroxide, and the removal rate of norfloxacin in an electro-Fenton system can reach 90%-100%. The carbon-modified foamy copper cathode combines the efficient hydrogen peroxide catalysis performance of copper and the excellent two-electron selective reduction oxygen production performance of a carbon material.

Description

Technical Field

[0001] The invention belongs to the technical field of environmental engineering, and specifically relates to a carbon-modified copper foam electrode, a preparation method and application thereof in producing hydrogen peroxide and treating antibiotic wastewater in an electro-Fenton system. Background Art

[0002] Fluoroquinolone antibiotics (FQs), such as norfloxacin (NOR), which is widely used in clinical practice, are widely used in the fields of medicine and veterinary medicine due to their broad-spectrum antibacterial activity, making them emerging pollutants in the environment. NOR mainly comes from pharmaceutical wastewater, hospital sewage, and aquaculture wastewater. Its environmental persistence and bioaccumulation make it a serious threat to the ecosystem. Studies have shown that NOR has significant toxicity to aquatic organisms, which can inhibit biological growth, cause reproductive disorders and decreased immune function, and even induce gene mutations. In addition, long-term low-concentration exposure to NOR may lead to the spread and diffusion of bacterial antibiotic resistance genes, exacerbating public health risks. At present, the removal technologies for NOR, such as biological treatment, adsorption, membrane separation, etc., have problems such as low efficiency, high cost and secondary pollution. Advanced oxidation technology, especially electro-Fenton technology, has a good application prospect because it produces strong oxidizing free radicals in situ and has a high efficiency in degrading NOR. Electro-Fenton technology avoids the traditional Fenton method's high pH and H 2 O 2 The dosage can be strictly controlled, and the removal efficiency can be improved by regulating the electrode materials, making it a potential advanced oxidation technology for treating NOR-contaminated water.

[0003] Although the existing homogeneous iron-based electro-Fenton technology is widely used, it is limited by strong acidic pH conditions and the problem that iron ions easily produce iron sludge precipitation. To overcome these shortcomings, the copper-based heterogeneous electro-Fenton technology came into being. With its wider pH application range, higher stability and catalytic efficiency advantages over iron-based catalysts, it is expected to replace the traditional iron-based electro-Fenton technology.

[0004] Metal foam is a porous metal material that forms countless three-dimensional spatial network structures in a metal matrix. It is composed of a rigid skeleton and internal pores. Because it has both metal properties and some special physical properties of non-metals, such as porosity, light weight, and high specific strength, metal foam has broad application prospects in the fields of catalysts, catalyst carriers, and porous electrodes. Due to the selection of different metal materials, different pore sizes, and different densities, there are many types of metal foams, including aluminum foam, magnesium foam, copper foam, iron foam, and nickel foam.

[0005] Carbon materials have become the most commonly used substrate or modified materials in electro-Fenton technology due to their excellent conductivity and low price. The application of carbon materials in electro-Fenton technology is not limited to electrode materials and catalyst carriers, and their performance can be further improved by compounding with other materials. For example, the combination of carbon nanotubes (CNTs) and metal oxides can form a composite material with high catalytic activity and stability, thereby improving the efficiency and two-electron selectivity of the electro-Fenton reaction. In addition, by introducing specific functional groups such as amino and hydroxyl groups on the surface of carbon materials, their adsorption capacity for organic pollutants can be enhanced, thereby further improving the degradation effect. Commonly used carbon materials in the electro-Fenton process include activated carbon, graphite, carbon fiber and carbon nanotubes. Carbon nanotubes are a one-dimensional quantum material with a special structure. Carbon atoms are formed into a hexagonal honeycomb structure by sp2 hybridization. Due to their high conductivity, large specific surface area and chemical stability, they show good catalytic activity in the electro-Fenton reaction.

[0006] As a copper-based electro-Fenton material, copper foam can significantly improve the catalytic performance of copper-based heterogeneous electro-Fenton with its high specific surface area, excellent conductivity and structural characteristics that are conducive to mass transfer. As a carbon-modified material, carbon nanotubes provide more sufficient Fenton reaction conditions for copper-based catalysts with their efficient two-electron oxygen reduction selective production of hydrogen peroxide and the adsorption properties of surface functional groups. In addition, carbon nanotube modification can also protect the copper foam electrode to a certain extent and improve its cyclic reaction stability.

[0007] Therefore, how to provide an electro-Fenton electrode material that couples the efficient catalytic performance of foam copper-based materials and the excellent two-electron selective oxygen reduction performance of carbon materials is a technical problem that needs to be solved urgently by those skilled in the art. Summary of the invention

[0008] In view of this, the present invention provides a carbon-modified copper foam electrode, a preparation method and an application thereof, which is a method for preparing an electric-Fenton electrode material based on carbon-modified copper foam with simple process and low cost. The electric-Fenton electrode material based on carbon-modified copper foam prepared by the method is used as a cathode. Under suitable pH conditions, the introduced oxygen is reduced to hydrogen peroxide on the surface of the carbon-modified copper foam electrode, and the obtained hydrogen peroxide is in-situ activated by the carbon-modified copper foam electrode to produce a large number of strongly oxidizing free radicals, which oxidatively degrade antibiotics in water.

[0009] In order to achieve the above object, the present invention adopts the following technical solution:

[0010] The first technical purpose of the present invention is to provide a method for preparing a carbon-modified modified copper foam electrode material, the steps being:

[0011] (1) Cut the original copper foam into small pieces and wash it with dilute hydrochloric acid solution, immerse it in an alkaline solution containing an oxidant, and react it at room temperature for 10-15 minutes to obtain Cu(OH) 2 @CF electrode; then, the Cu(OH) 2 @CF electrode was annealed in air atmosphere in a tube furnace to obtain Cu x O@CF (x=1~2) nanorod array electrode.

[0012] (2) The Cu x The O@CF (x=1~2) nanocolumn array electrode was immersed in a mixed solution containing ethanol, carboxylated carbon nanotubes (CNTs-COOH), Naifon solution and PTFE, and the immersed electrode was dried in an oven to obtain the carbon-modified modified copper foam cathode (PTFE / CNTs-COOH / Cu x O@CF) electrode.

[0013] It should be noted that the present invention conducts modification research on the basis of copper foam, utilizing the catalytic activity of metal oxides and the two-electron selective oxygen reduction activity of carbon nanotubes, firstly wet chemically oxidizing the copper foam and then annealing and modifying it in an air atmosphere to obtain copper oxide nanocolumns with catalytic activity, and then attaching carboxylated carbon nanotubes to the copper oxide nanocolumns to improve the oxygen reduction activity and protect the electrode. Therefore, the present invention proposes an electro-Fenton system with a modified carbon-modified copper foam electrode as a cathode and a platinum sheet electrode as an anode to achieve efficient and rapid degradation of antibiotic wastewater.

[0014] Optionally, the thickness of the original copper foam is 1-2 mm, and the PPI is 90-110; the alkaline solution containing the oxidant is a mixed solution of 2-3 M sodium hydroxide and 1-1.5 M ammonium persulfate; the annealing temperature is 200-300° C., and the annealing time is 20-40 minutes.

[0015] Optionally, the mixed solution is an ethanol solution containing 0.05-0.2wt% Naifon, 0.05-0.2wt% PTFE, and 0.1-0.2wt% carboxylated carbon nanotubes dispersed therein.

[0016] The second technical purpose of the present invention is to provide a carbon-modified copper foam electrode prepared by the above method, wherein the carbon-modified copper foam electrode is PTFE / CNTs-COOH / Cu x O@CF electrode.

[0017] The third technical purpose of the present invention is to provide an application of an electro-Fenton cathode material of a carbon-modified copper foam prepared by the above method in oxygen reduction to produce hydrogen peroxide in an electro-Fenton system, and the specific process is as follows:

[0018] The carbon-modified modified copper foam prepared above is used as a cathode connected to the negative electrode of a DC power supply, and a platinum sheet electrode is used as an anode connected to the positive electrode of a DC power supply. The electrolyte is a solution containing sodium sulfate, oxygen is aerated in the electrolyte, and oxygen is reduced to produce hydrogen peroxide by a constant current method.

[0019] The present invention also claims the use of an electro-Fenton cathode material of carbon-modified copper foam prepared by the above method in removing antibiotics from water, and the specific process is as follows:

[0020] The carbon-modified copper foam prepared as above is used as cathode connected to the negative electrode of a DC power supply, and the platinum sheet electrode is used as anode connected to the positive electrode of a DC power supply. The electrolyte is a solution containing sodium sulfate and antibiotics. Oxygen is aerated in the electrolyte, and the antibiotics are removed by electro-Fenton reaction in a constant current manner; oxygen is reduced on the cathode surface to generate hydrogen peroxide, and the obtained hydrogen peroxide is in-situ activated by the carbon-modified copper foam electrode to generate a large number of strong oxidizing free radicals, which oxidize and degrade antibiotics in water; the electrode after the reaction is rinsed with deionized water and then dried for repeated recycling.

[0021] Furthermore, the oxygen aeration rate in the electrolyte is 50-100 mL / min, the current of the DC power supply is 30-50 mA, the pH of the electrolyte is 3-7, and the antibiotic is a fluoroquinolone antibiotic.

[0022] Compared with the prior art, the present invention has the following beneficial effects:

[0023] 1) Low cost and easy preparation: This study used common foam copper as the substrate and prepared the cathode material through simple wet chemical oxidation, annealing and impregnation methods. No expensive precious metals are required, which greatly reduces the material cost. The preparation process is simple and easy, which is convenient for large-scale promotion and application.

[0024] 2) Excellent catalytic performance and high degradation efficiency: The carbon-modified copper foam cathode has a larger specific surface area and higher electrocatalytic activity. It can efficiently and selectively reduce oxygen with two electrons to produce hydrogen peroxide, and promote the Fenton reaction to produce a large number of free radicals, thereby achieving efficient degradation of antibiotics in water.

[0025] 3) Good stability and reusability: The modified copper foam cathode material has good stability and can maintain high catalytic activity after multiple cycles of use. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on the provided drawings without paying creative work.

[0027] Figure 1 is a scanning electron microscope image of the carbon-modified modified foam copper electrode prepared in Example 1;

[0028] Figure 2 This is the X-ray diffraction characterization result of the carbon-modified modified copper foam electrode prepared in Example 1;

[0029] Figure 3 The standard curve of hydrogen peroxide concentration by potassium titanium oxalate colorimetric method (a) is the carbon modified copper foam electrode and CF, Cu x Comparison of the cumulative amount of hydrogen peroxide produced by oxygen reduction in O@CF (x=1~2) nanorod array electrodes (b);

[0030] Figure 4 It is a carbon modified copper foam electrode and CF, Cu x Comparison of the effects of O@CF (x=1~2) nanorod array electrodes on the removal of norfloxacin from water;

[0031] Figure 5 is Cu at different annealing temperatures x XRD fine spectrum of O@CF (x=1~2) nanorod array electrode;

[0032] Figure 6 This is a comparison of the effects of carbon-modified copper foam electrodes with different carbon nanotube loadings on removing norfloxacin from water.

[0033] Figure 7 This is a comparison of the effects of carbon-modified copper foam electrode on the removal of norfloxacin at different concentrations in water.

[0034] Figure 8 This is a comparison of the effects of carbon-modified copper foam electrodes on the removal of norfloxacin from water under different aeration parameters;

[0035] Fig. 9 The results are as follows: the cyclic use of carbon-modified copper foam electrode to remove norfloxacin from water. DETAILED DESCRIPTION

[0036] The technical solutions in the embodiments of the present invention are described clearly and completely below. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of them. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0037] The word "embodiment" used here as an "exemplary" does not necessarily mean that any embodiment described is superior to or better than other embodiments. Unless otherwise specified, the performance index tests in the embodiments of this application are performed using conventional test methods in the art. It should be understood that the terms described in this application are only used to describe specific implementation methods and are not used to limit the content disclosed in this application.

[0038] Unless otherwise specified, the technical and scientific terms used in this document have the same meanings as commonly understood by ordinary technicians in the technical field to which this application belongs; other experimental methods and technical means not specifically specified in this application refer to experimental methods and technical means commonly used by ordinary technicians in this field.

[0039] In the description of the present invention, it is necessary to understand that the terms "middle", "upper", "lower", "ascending", "descending", "vertical", "face", "top", "bottom", "inside", "outside", etc., indicating the orientation or position relationship are based on the orientation or position relationship shown in the drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the referred device or element must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present invention.

[0040] In order to better illustrate the content of the present application, numerous specific details are provided in the specific examples below. It should be understood by those skilled in the art that the present application can also be implemented without certain specific details. In the embodiments, some methods, means, instruments, equipment, etc. well known to those skilled in the art are not described in detail in order to highlight the main purpose of the present application.

[0041] Under the premise of no conflict, the technical features disclosed in the embodiments of the present application can be combined arbitrarily, and the resulting technical solutions belong to the contents disclosed in the embodiments of the present application.

[0042] The invention discloses a carbon-modified modified foam copper electrode, a preparation method and application of the electrode in an electro-Fenton system for producing hydrogen peroxide and treating antibiotic wastewater.

[0043] In order to better understand the present invention, the present invention is further specifically described below through the following examples, but it should not be understood as a limitation of the present invention. Some non-essential improvements and adjustments made by technicians in this field based on the above invention content are also considered to fall within the protection scope of the present invention.

[0044] Embodiment 1:

[0045] Preparation of carbon-modified copper foam electro-Fenton cathode materials:

[0046] (1) The original copper foam cut into small pieces and cleaned with dilute hydrochloric acid solution was immersed in a mixed solution containing 2.5M sodium hydroxide and 1.125M ammonium persulfate for 15 minutes to obtain Cu(OH) 2 @CF electrode; then, Cu(OH) 2 @CF electrode was annealed in a tube furnace at 300°C for 30 minutes in air atmosphere to obtain Cu x O@CF (x=1~2) nanorod array electrode.

[0047] wt% Naifon, 0.05wt% PTFE, 0.1wt% carboxylated carbon nanotubes dispersed in ethanol solution; the electrode after impregnation was dried in an oven to obtain a carbon-modified modified copper foam cathode (PTFE / CNTs-COOH / Cu x O@CF) electrode.

[0048] In order to further demonstrate the beneficial effects of the present invention and to better understand the present invention, the following comparative examples and application examples are used to further illustrate the technical features disclosed in the present invention, but they should not be understood as limitations of the present invention. Other improvements made by those skilled in the art based on the above invention content without creative work are also considered to fall within the scope of protection of the present invention.

[0049] Application Example 1:

[0050] The carbon-modified copper foam cathode of Example 1 is used in an electro-Fenton system to produce hydrogen peroxide by oxygen reduction:

[0051] Prepare 50 mL of 0.05 M sodium sulfate electrolyte solution, use a carbon-modified copper foam electrode as the cathode, a platinum sheet as the anode, magnetic stirring, 100 mL / min oxygen aeration, and a DC power supply to remove norfloxacin from the water. Sampling is performed at fixed time intervals, and the cumulative amount of hydrogen peroxide is analyzed using a UV-visible spectrophotometer.

[0052] The results are as follows Figure 3 As shown by the yellow line, the obtained carbon-modified copper foam cathode can produce up to 30 mg / L of hydrogen peroxide in the electro-Fenton system.

[0053] Application Example 2:

[0054] Application of the carbon-modified copper foam cathode of Example 1 in removing norfloxacin from water in an electro-Fenton system:

[0055] 50 mL of a 5 mg / L ofloxacin solution was prepared, which contained a 0.05 M sodium sulfate electrolyte solution. A carbon-modified copper foam electrode was used as a cathode and a platinum sheet was used as an anode. Magnetic stirring, 100 mL / min oxygen aeration, and a DC power supply were used to remove norfloxacin from the water. Sampling was performed at fixed time intervals, and the removal rate of norfloxacin was analyzed using a UV-visible spectrophotometer.

[0056] The results are as follows Figure 4 As shown by the blue line, the obtained carbon-modified copper foam cathode almost 100% removed norfloxacin from water in the electro-Fenton system.

[0057] Application Experiment Example 2-1:

[0058] Cu(OH) in Example 1 2 @CF cathode annealing temperature preparation parameter optimization experiment.

[0059] In air atmosphere, Cu(OH) 2 @CF electrode was placed in a tube furnace for annealing to obtain Cu at different annealing temperatures. x O@CF electrode.

[0060] like Figure 5 As shown in Figure 2, when the annealing temperature is close to 300°C, the Cu x The monovalent copper content of the O@CF electrode reaches the highest. Although annealing at a higher temperature may further increase the monovalent copper content, experiments have found that the foam copper substrate annealed in an air atmosphere at 330°C will break, resulting in material structure damage. Therefore, considering the monovalent copper content and the structural stability of the material, the optimal annealing temperature parameter of the present invention is 290°C - 310°C, and 300°C is finally selected as the optimal annealing temperature parameter. This temperature can maximize the content of monovalent copper in the material while ensuring the structural integrity of the material.

[0061] Application Example 2-2:

[0062] Optimal carbon nanotube loading parameters during the preparation of carbon-modified copper foam cathode for removal of norfloxacin from water in an electro-Fenton system.

[0063] wt% Naifon, 0.05wt% PTFE, 0.1wt% carboxylated carbon nanotubes dispersed in ethanol solution; the electrode after impregnation was dried in an oven to obtain a carbon-modified modified copper foam cathode (PTFE / CNTs-COOH / Cu x O@CF) electrode.

[0064] 50 mL of 5 mg / L ofloxacin solution was prepared, which contained 0.05 M sodium sulfate electrolyte solution. A carbon-modified copper foam electrode was used as the cathode and a platinum sheet was used as the anode. Magnetic stirring, 100 mL / min oxygen aeration, and DC power supply were used to remove norfloxacin from the water. Sampling was performed at fixed time intervals, and the removal rate of norfloxacin was analyzed using a UV-visible spectrophotometer.

[0065] The results are as follows Figure 6 As shown, when the norfloxacin concentration was 5 mg / L, the obtained carbon-modified copper foam cathode had the fastest removal efficiency in the electro-Fenton system.

[0066] Application Example 2-3:

[0067] The concentration parameters are optimized when the carbon-modified copper foam cathode of Example 1 is used in an electro-Fenton system to remove norfloxacin from water.

[0068] wt% Naifon, 0.05wt% PTFE, 0.1wt% carboxylated carbon nanotubes dispersed in ethanol solution for different times; the electrode after impregnation was dried in an oven, and the carbon modified copper foam cathode with different carbon nanotube loadings (PTFE / CNTs-COOH / Cu x O@CF) electrode.

[0069] 50 mL of 5 mg / L and 10 mg / L ofloxacin solutions were prepared, each containing 0.05 M sodium sulfate electrolyte solution. A carbon-modified copper foam electrode was used as a cathode and a platinum sheet was used as an anode. Magnetic stirring, 100 mL / min oxygen aeration, and DC power supply were used to remove norfloxacin from the water. Sampling was performed at fixed time intervals, and the removal rate of norfloxacin was analyzed using a UV-visible spectrophotometer.

[0070] The results are as follows Figure 7 As shown in the figure, when the carbon nanotube loading is 1 mg / cm -2 When , the obtained carbon-modified modified copper foam cathode has the fastest removal efficiency in the electro-Fenton system.

[0071] Application Examples 2-4:

[0072] The carbon-modified copper foam cathode of Example 1 is used to optimize aeration parameters when removing norfloxacin from water in an electro-Fenton system.

[0073] Prepare 50 mL of 5 mg / L ofloxacin solution, which contains 0.05 M sodium sulfate electrolyte solution, use carbon modified copper foam electrode as cathode, platinum sheet as anode, and magnetic stirring. Remove norfloxacin from water under no aeration, 50 mL / min oxygen aeration, 100 mL / min oxygen aeration, and DC power supply. Sampling is performed at fixed time intervals, and the removal rate of norfloxacin is analyzed by UV-visible spectrophotometer.

[0074] The results are as follows Figure 8 As shown, when the oxygen aeration rate is 100 mL / min, the obtained carbon-modified modified copper foam cathode has the fastest removal efficiency in the electro-Fenton system.

[0075] Application Example 3:

[0076] Application of the carbon-modified modified copper foam cathode of Example 1 in the electro-Fenton system for removing norfloxacin from water:

[0077] 50 mL of a 5 mg / L ofloxacin solution was prepared, which contained a 0.05 M sodium sulfate electrolyte solution. A carbon-modified copper foam electrode was used as a cathode and a platinum sheet was used as an anode. Magnetic stirring and 100 mL / min oxygen aeration were performed under a DC power supply to remove norfloxacin from the water. Sampling was performed at fixed time intervals, and the removal rate of norfloxacin was analyzed using a UV-visible spectrophotometer. The electrode was washed with deionized water and then dried and reused 5 times.

[0078] The results are as follows Fig. 9 As shown, the obtained carbon-modified copper foam cathode still maintained an efficiency of 85% in removing norfloxacin from water after five cycles in the electro-Fenton system.

[0079] Application Comparative Example 1:

[0080] The CF and Cu of Example 1 x Application of O@CF (x=1~2) nanorod array electrodes in electro-Fenton systems for oxygen reduction to produce peroxide:

[0081] Prepare 50 mL of 0.05 M sodium sulfate electrolyte solution. x O@CF (x=1~2) nanorod array electrodes were used as cathodes, platinum sheets were used as anodes, magnetic stirring, 100mL / min oxygen aeration, and DC power supply to remove norfloxacin from simulated wastewater. Sampling was performed at fixed time intervals, and the potassium titanium oxalate colorimetric method was used to develop the color. The absorbance at 400nm was detected using a UV-visible spectrophotometer, and the cumulative amount of hydrogen peroxide was analyzed based on the hydrogen peroxide standard curve.

[0082] The results are as follows Figure 3As shown by the red and black lines, the accumulated amount of hydrogen peroxide in the electro-Fenton system of the copper foam cathode before modification was less than 10 mg / L.

[0083] Application Comparative Example 2:

[0084] The CF and Cu of Example 1 x Application of O@CF (x=1~2) nanorod array electrode in electro-Fenton system for removal of norfloxacin in water:

[0085] Prepare 50 mL of 5 mg / L norfloxacin solution containing 0.05 M sodium sulfate electrolyte solution. x O@CF (x=1~2) nanorod array electrodes were used as cathodes, platinum sheets were used as anodes, magnetic stirring, 100mL / min oxygen aeration, and DC power supply to remove norfloxacin from water. Sampling was performed at fixed time intervals, and the absorbance at 278nm was detected by UV-visible spectrophotometer to analyze the removal rate of norfloxacin.

[0086] The results are as follows Figure 4 As shown by the blue and green lines, the copper foam cathode before modification had poor effect in removing norfloxacin from water in the electro-Fenton system.

[0087] The above description of the disclosed embodiments enables one skilled in the art to implement or use the present invention. Various modifications to these embodiments will be apparent to one skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the present invention. Therefore, the present invention will not be limited to the embodiments shown herein, but rather to the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A method for preparing a carbon-modified copper foam electrode, characterized in that: The following steps are involved: (1) The original copper foam cut into small pieces and cleaned with a dilute hydrochloric acid solution is immersed in an alkaline solution containing an oxidant, and reacted at room temperature for 10-15 minutes to obtain a Cu(OH)2@CF electrode; then, the Cu(OH)2@CF electrode is annealed in an air atmosphere in a tube furnace to obtain a Cu x O@CF, nanopillar array electrode with x=1~2; (2) The Cu prepared in step (1) x O@CF, the nanorod array electrode with x=1~2 is immersed in a mixed solution containing ethanol, carboxylated carbon nanotubes (CNTs-COOH), Naifon and PTFE, and the immersed electrode is dried in an oven to obtain the carbon-modified modified copper foam electrode, PTFE / CNTs-COOH / Cu x O@CF electrode.

2. The preparation method according to claim 1, characterized in that: The thickness of the original copper foam is 1-2 mm, and the PPI is 90-110; the alkaline solution containing the oxidant is a mixed solution of 2-3 M sodium hydroxide and 1-1.5 M ammonium persulfate; the annealing temperature is 200-300° C., and the annealing time is 20-40 minutes.

3. The preparation method according to claim 1, characterized in that: The mixed solution is an ethanol solution containing 0.05-0.2wt% Naifon solution, 0.05-0.2wt% PTFE, and 0.1-0.2wt% carboxylated carbon nanotubes.

4. A carbon-modified copper foam electrode prepared by the method according to any one of claims 1 to 3, characterized in that: The carbon modified copper foam electrode is PTFE / CNTs-COOH / Cu x O@CF electrode.

5. Use of a carbon-modified copper foam electrode prepared by the method according to any one of claims 1 to 3 in oxygen reduction to produce hydrogen peroxide in an electro-Fenton system.

6. The use according to claim 5, characterized in that: The following steps are involved: In an electrolyte solution containing sodium sulfate, the carbon-modified modified foam copper electrode is used as a cathode, a platinum sheet is used as an anode, and oxygen is introduced near the cathode to perform oxygen reduction to generate hydrogen peroxide.

7. Use of a carbon-modified copper foam electrode prepared by the method according to any one of claims 1 to 3 in an electro-Fenton system for removing antibiotics from water.

8. The use according to claim 7, characterized in that: The following steps are involved: (1) In a sodium sulfate solution containing antibiotics, the carbon-modified copper foam electrode is used as a cathode, a platinum sheet is used as an anode, and oxygen is introduced near the cathode to build an electro-Fenton system; (2) A voltage of 2.0-3.0 V is applied to the electro-Fenton system while the solution is stirred. The carbon-modified copper foam electrode reduces oxygen to produce hydrogen peroxide under the action of an external negative electric field. At the same time, the hydrogen peroxide is activated by the carbon-modified copper foam electrode to produce strong oxidizing free radicals to oxidize antibiotics, thereby achieving the purpose of removing antibiotics from water.

9. The use according to claim 8, characterized in that: The antibiotics in the solution include fluoroquinolone antibiotics.

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