Large-area, high-efficiency, stable composite electrode material and its preparation method and application

Abstract

The present invention discloses a process for preparing a large-area, high-efficiency, and stable composite electrode material. The material is prepared by the following method: Step 1: Dispersing a powdered catalyst in a certain PTFE aqueous solution to synthesize a desired catalyst slurry, using a sprayer to evenly spray the catalyst slurry onto a needle-punched carbon fiber felt of a certain thickness according to a specific spraying process and carbonizing it; Step 2: Mixing a phenolic resin solution of a certain mass fraction with a conductive agent in a specific mass ratio to form a conductive slurry with a certain viscosity; Step 3: Applying the synthesized conductive slurry onto a stainless steel mesh, and then bonding the catalyst-containing needle-punched carbon fiber felt and the stainless steel mesh by brushing to form a "sandwich" electrode and curing it to obtain the desired composite electrode material. The process is simple to prepare, and the prepared electrode can be composited with a variety of powdered electrode materials. The electrode has the advantages of high efficiency and stability, and is suitable for electrocatalytic production of hydrogen peroxide and advanced oxidation treatment of water pollution.

Description

Technical Field

[0001] The present invention relates to the technical field of material chemistry, and in particular to a large-area, high-efficiency, stable composite electrode material and a preparation method and application thereof. Background Art

[0002] Water pollution is a serious problem today. It is well known that a large number of synthetic organic pollutants, including industrial chemicals, pesticides, dyes, pharmaceuticals, and personal care products, are discharged into various types of wastewater daily and enter natural waterways, accumulating in the aquatic environment. These pollutants are persistent organic pollutants (POPs) that are resistant to high temperatures and microbial attack, necessitating an urgent need for their treatment. Conventional methods for wastewater treatment include isolation / separation technologies based on physical and chemical methods and conversion technologies based on chemical and microbial / enzymatic methods. These traditional water treatment methods have certain limitations and are inefficient in removing many toxic and recalcitrant pollutants. Therefore, it is particularly important to develop a safe, efficient, simple, and economical treatment technology.

[0003] The main advantage of electrochemical treatment of water pollution is environmental compatibility, because the main reagent electron is a cleaning reagent. In addition, it has the advantages of versatility, high energy efficiency, easy automation, and safety. Traditional treatment methods such as electrocoagulation, electroflotation, electrochemical reduction, electrochlorination, etc. can only partially remove POPs and / or produce harmful by-products. Advanced Oxidation Processes (AOPs) have been widely studied as an environmentally friendly treatment method because it produces highly efficient reactive oxygen species (ROS) during the reaction process, which can continuously decompose POPs into smaller compounds and even carbon dioxide. The most common chemical AOPs is the electro-Fenton method, in which Fe 2+ The hydroxyl radicals (HO·) produced by the reaction with Fenton's reagent (H2O2) have high oxidative activity and can effectively degrade POPs.

[0004] Researchers are currently focusing on developing greener, safer and more efficient methods to continuously generate H2O2. -) Direct oxygen reduction to generate H2O2 is a promising method with the characteristics of reducing waste emissions, lowering energy consumption and improving safety. However, in the electro-Fenton reaction, on the one hand, the production rate of H2O2 is greatly limited, and its efficiency depends largely on the properties of the cathode working electrode and its material. On the other hand, the stability of the electrode is limited. The preparation of the working electrode can be improved from four aspects: base material, conductive agent, coating method and binder. Based on the above problems, how to design a large-area, efficient and stable electrode that is easy to use has become the key to solving the bottleneck problem of the Fenton reaction. Summary of the Invention

[0005] The purpose of the present invention is to address the technical defects existing in the prior art and provide a method for preparing large-area, high-efficiency and stable composite electrode materials. The preparation process of this method is simple, and the prepared electrode can be composited with a variety of powdered electrode materials, which is significantly superior to other base materials.

[0006] Another object of the present invention is to provide a composite electrode material prepared by the preparation process, which has advantages over other electrodes such as high efficiency, stability, large area, and reusability.

[0007] Another object of the present invention is to provide a large-area, high-efficiency, stable composite electrode material prepared by the preparation process, which has an excellent catalytic effect in the preparation of hydrogen peroxide by two-electron oxygen reduction.

[0008] Another object of the present invention is to provide a large-area, high-efficiency, stable composite electrode material prepared by the preparation process for use in electro-Fenton advanced oxidation treatment of water pollution, which has excellent treatment effect.

[0009] The technical solution adopted to achieve the purpose of the present invention is:

[0010] A method for preparing a large-area, high-efficiency, and stable composite electrode material comprises the following steps:

[0011] Step 1: Disperse the powdered catalyst in a PTFE aqueous solution to synthesize the required catalyst slurry, spray the catalyst slurry evenly on the needle-punched carbon fiber felt, and carbonize it in an air atmosphere at 250-400° C. for 0.25-2 hours;

[0012] Step 2: mixing the phenolic resin solution and the conductive agent in a predetermined ratio under a magnetic stirrer to form a conductive slurry with viscosity;

[0013] In step 3, the conductive slurry synthesized in step 2 is evenly applied on the stainless steel mesh, and then the needle-punched carbon fiber felt with catalyst prepared in step 1 is bonded to the stainless steel mesh. During bonding, the stainless steel mesh is located in the middle, and a layer of needle-punched carbon fiber felt with catalyst prepared in step 1 is bonded on its left and right sides. Then, the mixture is cured in an electric blast drying oven to obtain the desired composite electrode material.

[0014] In the above technical solution, the type of powdered catalyst in step 1 (including N-doped C materials, metal carbon-based materials, metal oxides and MOF, COF materials) and the early synthesis preparation method are not limited.

[0015] In the above technical solution, the mass fraction of the PTFE aqueous solution in step 1 is 10-30 wt.%, and the thickness of the needle-punched carbon fiber felt is less than or equal to 1 mm.

[0016] In the above technical solution, a sprayer is used for spraying in step 1, and the spraying process is as follows: the heating plate temperature is 50-90°C, the glue barrel pressure is 10-15Pa, the nozzle pressure is 10-15Pa, and the nozzle moving speed is 200-400mm s -1 , flow rate is 3-5, catalyst loading is 0.1-1 mg cm -2 .

[0017] In the above technical solution, the mass fraction of the phenolic resin solution in step 2 is 30-60 wt.%, and the mass ratio of the phenolic resin solution to the conductive agent in step 2 is 10:(1-7).

[0018] In the above technical solution, the types of conductive agents in step 2 include one or more of spherical stainless steel powder, ultrafine stainless steel powder, carbon black, multi-walled carbon nanotubes, natural graphite powder, nanographite powder, acetylene black, Ketjen black and Super P.

[0019] In the above technical solution, the coating method in step 3 is dipping, scraping or brushing, the curing temperature in step 3 is 100-150° C., and the curing time is 0.5h-24h.

[0020] Another aspect of the present invention also includes a large-area, high-efficiency, and stable composite electrode material prepared by the method.

[0021] Another aspect of the present invention also includes the use of the large-area, high-efficiency, stable composite electrode material as a working electrode in the production of hydrogen peroxide by two-electron oxygen reduction.

[0022] Another aspect of the present invention also includes the use of the large-area, high-efficiency, stable composite electrode material as a working electrode in electro-Fenton advanced oxidation treatment of water pollution.

[0023] In the above technical solution, the interlayer resistance of the working electrode is 0.5-1.5Ω.

[0024] Compared with the prior art, the present invention has the following beneficial effects:

[0025] 1. Compared with the traditional monolithic method for preparing working electrodes, the "sandwich" working electrode has the advantages of large area, stability, and high efficiency. It can maintain its intact structure in wastewater environments for a long time, increase the exposed area of powdered catalysts, and can be composited with a variety of powdered catalysts;

[0026] 2. The conductive paste formed by mixing phenolic resin solution with different conductive agents can fully reduce the resistance between the internal layers of the electrode and effectively reduce current loss;

[0027] 3. The prepared large-area, high-efficiency, and stable composite electrode material has a simple preparation process, excellent electrochemical performance, low cost, and is easy to achieve industrial production. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] Figure 1 Schematic diagram of the structure of the composite electrode material prepared in Example 1;

[0029] Figure 2 This is a scanning electron microscope image of the catalyst loaded on the surface of the composite electrode material prepared in Example 1;

[0030] Figure 3 is a scanning electron microscope image of the N-doped C powdered catalyst used in the examples and comparative examples;

[0031] Figure 4 This is a scanning electron microscope image of the bonding portion between stainless steel and carbon surface felt in the composite electrode material prepared in Example 1;

[0032] Figure 5 This is a performance diagram of the composite electrode material prepared in Example 1 for preparing hydrogen peroxide by two-electron oxygen reduction;

[0033] Figure 6 This is a performance diagram of the composite electrode material prepared in Comparative Example 1 for preparing hydrogen peroxide by two-electron oxygen reduction;

[0034] Figure 7 This is a graph showing the degradation rate of neutral red dye of the composite electrode material prepared in Example 1.

[0035] Figure 8 Schematic diagram of the structure of the composite electrode material prepared in Comparative Example 3. DETAILED DESCRIPTION

[0036] The present invention will be further described in detail below with reference to specific embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not intended to limit the present invention.

[0037] Example 1

[0038] A process for preparing a large-area, high-efficiency, and stable composite electrode material comprises the following steps:

[0039] (1) The N-doped C powder catalyst was dispersed in a PTFE aqueous solution with a mass fraction of 20 wt.% to synthesize the required catalyst slurry. The catalyst slurry was evenly sprayed on a needle-punched carbon fiber felt with a thickness of 1 mm using a sprayer. The spraying process was as follows: the heating plate temperature was 90 °C, the glue barrel pressure was 15 Pa, the nozzle pressure was 15 Pa, and the nozzle movement speed was 400 mm s -1 , flow rate of 4.8, catalyst loading of 0.3 mg cm -2 The sprayed needle-punched carbon fiber felt was carbonized in a muffle furnace at 360°C in air atmosphere for 0.5 h.

[0040] (2) mixing a phenolic resin solution having a mass fraction of 40 wt.% with a conductive agent acetylene black at a mass ratio of (10:3) g, stirring and dispersing the mixture uniformly under a magnetic stirrer to form a conductive paste having a certain viscosity;

[0041] (3) The conductive slurry synthesized in step 2 is evenly coated on the stainless steel mesh, and then the needle-punched carbon fiber felt with catalyst prepared in step 1 is bonded to the stainless steel mesh. During bonding, the stainless steel mesh is located in the middle, and a layer of needle-punched carbon fiber felt with catalyst prepared in step 1 is bonded on both sides to form a "sandwich" structure. The structure is cured at 150°C in an electric blast drying oven for 24 hours to obtain the desired composite electrode material.

[0042] The structural diagram of the composite electrode material prepared in this embodiment is shown in FIG. Figure 1 As shown in the scanning electron microscope image Figure 2 The scanning electron micrograph of the powdered catalyst used is shown in FIG. Figure 3 As shown. Figure 2 、 3 By comparison, it can be seen that the composite electrode material still retains the original morphology of the powdered electrode material during preparation.

[0043] Depend on Figure 4 It can be seen that the conductive paste of the bonding part between stainless steel and needle-punched carbon felt in the composite electrode material is evenly coated on the carbon fiber surface.

[0044] Example 2

[0045] Electrochemical tests were performed using the working electrode:

[0046] (1) Two-electron oxygen reduction to hydrogen peroxide: The electrochemical test was carried out in 0.1M KOH, O2-saturated electrolyte, using a CHI760E electrochemical workstation. The system used platinum (Pt) foil and Ag / AgCl (saturated KCl aqueous solution) as the counter electrode and reference electrode, respectively. The H2O2 concentration was measured every 1 h of the reaction. The two-electron oxygen reduction to H2O2 of the composite electrode material prepared in Example 1 is shown in FIG. Figure 5 As shown in the figure, after 3 hours of reaction, the cumulative concentration of H2O2 is 384.2 mg L -1 After 5 h of reaction, the cumulative concentration of H2O2 was 491.6 mg L -1 .

[0047] (2) Electro-Fenton advanced oxidation treatment of water pollution: The advanced oxidation treatment of water pollution experiment was carried out in a volume of 2.5 L, pH = 3, 0.1 M NaSO4, 50 mg L -1 After being treated in neutral red electrolyte for 5 h, the overall dye concentration increased from the original 50 mg L -1 Reduced to 1.8 mg L -1 The degradation effect of the dye is very significant, and the degradation rate is shown in the figure below. Figure 6 shown.

[0048] The electrochemical properties of other materials were characterized using the same electrochemical test, and the results are shown in the following comparative examples.

[0049] Example 3

[0050] In this embodiment, the conductive agent is replaced with carbon black.

[0051] A process for preparing a large-area, high-efficiency, and stable composite electrode material comprises the following steps:

[0052] (1) The N-doped C powder catalyst was dispersed in a PTFE aqueous solution with a mass fraction of 20 wt.% to synthesize the required catalyst slurry. The catalyst slurry was evenly sprayed on a needle-punched carbon fiber felt with a thickness of 1 mm using a sprayer. The spraying process was as follows: the heating plate temperature was 90 °C, the glue barrel pressure was 15 Pa, the nozzle pressure was 15 Pa, and the nozzle movement speed was 400 mm s -1 , flow rate of 4.8, catalyst loading of 0.3 mg cm -2 The sprayed needle-punched carbon fiber felt was carbonized in a muffle furnace at 360°C in air atmosphere for 0.5 h.

[0053] (2) mixing a phenolic resin solution having a mass fraction of 40 wt.% with a conductive agent carbon black at a mass ratio of (10:3) g, stirring and dispersing the mixture uniformly under a magnetic stirrer to form a conductive slurry having a certain viscosity;

[0054] (3) First, the conductive slurry synthesized in step 2 is evenly coated on the stainless steel mesh, and then the needle-punched carbon fiber felt with catalyst prepared in step 1 is bonded to the stainless steel mesh. During bonding, the stainless steel mesh is located in the middle, and a layer of needle-punched carbon fiber felt with catalyst prepared in step 1 is bonded on both sides to form a "sandwich" structure. The structure is then cured in an electric blast drying oven to obtain the desired composite electrode material.

[0055] After 3 h of reaction, the cumulative concentration of H2O2 in the working electrode prepared in this comparative example was 242.9 mg L -1 After 5 h of reaction, the cumulative concentration of H2O2 was 320.9 mg L -1 .

[0056] Example 4

[0057] In this embodiment, the conductive agent is replaced with multi-walled carbon nanotubes (MWCNTs).

[0058] A process for preparing a large-area, high-efficiency, and stable composite electrode material comprises the following steps:

[0059] (1) The N-doped C powder catalyst was dispersed in a PTFE aqueous solution with a mass fraction of 20 wt.% to synthesize the required catalyst slurry. The catalyst slurry was evenly sprayed on a needle-punched carbon fiber felt with a thickness of 1 mm using a sprayer. The spraying process was as follows: the heating plate temperature was 90 °C, the glue barrel pressure was 15 Pa, the nozzle pressure was 15 Pa, and the nozzle movement speed was 400 mm s -1 , flow rate of 4.8, catalyst loading of 0.3 mg cm -2 The sprayed needle-punched carbon fiber felt was carbonized in a muffle furnace at 360°C in air atmosphere for 0.5 h.

[0060] (2) mixing a phenolic resin solution with a mass fraction of 40 wt.% and a conductive agent multi-walled carbon nanotubes (MWCNTs) at a mass ratio of (10:3) g, stirring and dispersing them uniformly under a magnetic stirrer to form a conductive slurry with a certain viscosity;

[0061] (3) First, the conductive slurry synthesized in step 2 is evenly coated on the stainless steel mesh, and then the needle-punched carbon fiber felt with catalyst prepared in step 1 is bonded to the stainless steel mesh. During bonding, the stainless steel mesh is located in the middle, and a layer of needle-punched carbon fiber felt with catalyst prepared in step 1 is bonded on both sides to form a "sandwich" structure. The structure is then cured in an electric blast drying oven to obtain the desired composite electrode material.

[0062] After 3 h of reaction, the cumulative concentration of H2O2 in the working electrode prepared in this comparative example was 262.2 mg L -1 After 5 h of reaction, the cumulative concentration of H2O2 was 309.1 mg L-1 .

[0063] Comparative Example 1

[0064] Different from Example 1, this comparative example uses a needle-punched carbon fiber felt with a thickness of 2 mm.

[0065] A process for preparing a large-area, high-efficiency, and stable composite electrode material comprises the following steps:

[0066] (1) The N-doped C powder catalyst was dispersed in a PTFE aqueous solution with a mass fraction of 20 wt.% to synthesize the required catalyst slurry. The catalyst slurry was evenly sprayed on a needle-punched carbon fiber felt with a thickness of 2 mm using a sprayer. The spraying process was as follows: the heating plate temperature was 90 °C, the glue barrel pressure was 15 Pa, the nozzle pressure was 15 Pa, and the nozzle movement speed was 400 mm s -1 , flow rate of 4.8, catalyst loading of 0.3 mg cm -2 The sprayed needle-punched carbon fiber felt was carbonized in a muffle furnace at 360°C in air atmosphere for 0.5 h.

[0067] (2) mixing a phenolic resin solution having a mass fraction of 40 wt.% with a conductive agent acetylene black at a mass ratio of (10:3) g, stirring and dispersing the mixture uniformly under a magnetic stirrer to form a conductive paste having a certain viscosity;

[0068] (3) First, the conductive slurry synthesized in step 2 is evenly coated on the stainless steel mesh, and then the needle-punched carbon fiber felt with catalyst prepared in step 1 is bonded to the stainless steel mesh. During bonding, the stainless steel mesh is located in the middle, and a layer of needle-punched carbon fiber felt with catalyst prepared in step 1 is bonded on both sides to form a "sandwich" structure. The structure is then cured in an electric blast drying oven to obtain the desired composite electrode material.

[0069] like Figure 7 As shown in the figure, after 3 hours of reaction, the cumulative concentration of H2O2 in the working electrode prepared in this comparative example was 240.0 mg L -1 After 5 h of reaction, the cumulative concentration of H2O2 was 325.5 mg L -1 .

[0070] Comparative Example 2

[0071] Different from Example 1, this comparative example uses carbon felt. Since carbon felt is not as dense as needle-punched felt and has a loose structure, it is pretreated to ensure its firmness while improving its conductivity.

[0072] A process for preparing a large-area, high-efficiency, and stable composite electrode material comprises the following steps:

[0073] (1) Before the experiment, the purchased carbon surface felt needs to be pretreated. The steps are as follows: use a sprayer to evenly spray 2 wt.% phenolic resin solution on the carbon surface felt. The spraying process is as follows: the heating plate temperature is 50 ° C, the glue barrel pressure is 15 Pa, the nozzle pressure is 15 Pa, and the nozzle movement speed is 400 mm s -1 , flow rate is 3.5, and the amount of phenolic resin solution is 30mL.

[0074] The sprayed carbon surface felt was cured in an electric forced-air drying oven at 100°C for 24 hours. The cured carbon surface felt then underwent high-temperature treatment in a tube furnace. The high-temperature treatment conditions were as follows: first, the temperature was maintained at 60°C for 1 hour, then increased to 900°C at a rate of 5°C / min, maintained for 2 hours, and finally decreased to 300°C for 100 minutes. This resulted in the pre-treated carbon surface felt.

[0075] (2) The N-doped C powder catalyst was dispersed in a PTFE aqueous solution with a mass fraction of 20 wt.% to synthesize the required catalyst slurry. The catalyst slurry was evenly sprayed on the carbon surface felt treated in step 1 using a sprayer. The spraying process was as follows: the heating plate temperature was 90 °C, the glue barrel pressure was 15 Pa, the nozzle pressure was 15 Pa, and the nozzle movement speed was 400 mm s -1 , flow rate of 4.8, catalyst loading of 0.3 mg cm -2 The sprayed needle-punched carbon fiber felt was carbonized in a muffle furnace at 360°C in air atmosphere for 0.5 h.

[0076] (3) mixing a phenolic resin solution having a mass fraction of 40 wt.% with a conductive agent acetylene black at a mass ratio of (10:3) g, stirring and dispersing the mixture uniformly under a magnetic stirrer to form a conductive paste having a certain viscosity;

[0077] (4) The conductive slurry synthesized in step 3 is evenly coated on the stainless steel mesh, and then the carbon surface felt with catalyst prepared in step 2 is bonded to the stainless steel mesh. During bonding, the stainless steel mesh is located in the middle, and a layer of needle-punched carbon fiber felt with catalyst prepared in step 1 is bonded on both sides to form a "sandwich" structure, which is then cured in an electric hot air drying oven to obtain the desired composite electrode material.

[0078] After 3 h of reaction, the cumulative concentration of H2O2 in the working electrode prepared in this comparative example was 212.0 mg L -1 After 5 h of reaction, the cumulative concentration of H2O2 was 248.8 mg L -1 .

[0079] Comparative Example 3

[0080] Different from Example 1, this comparative example changed the electrode preparation form and adopted a "double-layer" structure.

[0081] A process for preparing a large-area, high-efficiency, and stable composite electrode material comprises the following steps:

[0082] (1) The N-doped C powder catalyst was dispersed in a PTFE aqueous solution with a mass fraction of 20 wt.% to synthesize the required catalyst slurry. The catalyst slurry was evenly sprayed on a needle-punched carbon fiber felt with a thickness of 1 mm using a sprayer. The spraying process was as follows: the heating plate temperature was 90 °C, the glue barrel pressure was 15 Pa, the nozzle pressure was 15 Pa, and the nozzle movement speed was 400 mm s -1 , flow rate of 4.8, catalyst loading of 0.3 mg cm -2 The sprayed needle-punched carbon fiber felt was carbonized in a muffle furnace at 360°C in air atmosphere for 0.5 h.

[0083] (2) mixing a phenolic resin solution having a mass fraction of 40 wt.% with a conductive agent acetylene black at a mass ratio of (10:3) g, stirring and dispersing the mixture uniformly under a magnetic stirrer to form a conductive paste having a certain viscosity;

[0084] (3) First, the conductive paste synthesized in step 2 is evenly coated on the stainless steel mesh, and then the needle-punched carbon fiber felt with catalyst prepared in step 1 is bonded to the stainless steel mesh to form a "double-layer" electrode, and then cured in an electric heating blast drying oven to obtain the desired composite electrode material. The structural diagram of the composite electrode material prepared in this comparative example is shown in FIG. Figure 8 shown.

[0085] After 3 h of reaction, the cumulative concentration of H2O2 in the working electrode prepared in this comparative example was 41.1 mg L -1 After 5 h of reaction, the cumulative concentration of H2O2 was 48.6 mg L -1 It can be seen that the "sandwich" electrode has higher performance than the "double-layer" electrode, proving the superiority of the "sandwich" structure.

[0086] The above is only a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principles of the present invention. These improvements and modifications should also be regarded as the scope of protection of the present invention.

Claims

1. A method for preparing a large-area, high-efficiency, and stable composite electrode material, characterized in that: The following steps are involved: Step 1: Dispersing a powdered catalyst in a PTFE aqueous solution to synthesize a desired catalyst slurry, spraying the catalyst slurry evenly on a needle-punched carbon fiber felt, and carbonizing the felt at 250-400° C. in an air atmosphere for 0.25-2 h; Step 2: mixing the phenolic resin solution and the conductive agent in a predetermined ratio under a magnetic stirrer to form a conductive slurry with viscosity; The mass fraction of the phenolic resin solution in step 2 is 30-60 wt.%, and the mass ratio of the phenolic resin solution to the conductive agent in step 2 is 10:(1-7); In step 3, the conductive slurry synthesized in step 2 is evenly applied on the stainless steel mesh, and then the needle-punched carbon fiber felt with catalyst prepared in step 1 is bonded to the stainless steel mesh. During bonding, the stainless steel mesh is located in the middle, and a layer of needle-punched carbon fiber felt with catalyst prepared in step 1 is bonded on its left and right sides. Then, the mixture is cured in an electric blast drying oven to obtain the desired composite electrode material.

2. The method for preparing a large-area, high-efficiency, stable composite electrode material according to claim 1, characterized in that: The powdered catalyst in step 1 is an N-doped C material, a metal carbon-based material, a metal oxide, or an MOF or COF material.

3. The method for preparing a large-area, high-efficiency, stable composite electrode material according to claim 1, characterized in that: The mass fraction of the PTFE aqueous solution in step 1 is 10-30 wt.%.

4. The method for preparing a large-area, high-efficiency, stable composite electrode material according to claim 1, characterized in that: The thickness of the needle-punched carbon fiber felt is less than or equal to 1 mm.

5. The method for preparing a large-area, high-efficiency, stable composite electrode material according to claim 1, characterized in that: In step 1, a sprayer is used for spraying. The spraying process is as follows: the heating plate temperature is 50-90 °C, the glue barrel pressure is 10-15 Pa, the nozzle pressure is 10-15 Pa, and the nozzle movement speed is 200-400 mm s -1 , flow rate is 3~5, catalyst loading is 0.1~1 mg cm -2 .

6. The method for preparing a large-area, high-efficiency, stable composite electrode material according to claim 1, characterized in that: The types of the conductive agent in step 2 include one or more of spherical stainless steel powder, ultrafine stainless steel powder, carbon black, multi-walled carbon nanotubes, natural graphite powder, nanographite powder, acetylene black, Ketjen black and Super P.

7. The method for preparing a large-area, high-efficiency, stable composite electrode material according to claim 1, characterized in that: The coating method in step 3 is dipping, scraping or brushing. The curing temperature in step 3 is 100-150° C. and the curing time is 0.5 h-24 h.

8. A large-area, high-efficiency, stable composite electrode material prepared by the method according to any one of claims 1 to 7.

9. Use of the large-area, high-efficiency, stable composite electrode material according to claim 8 as a working electrode in two-electron oxygen reduction to produce hydrogen peroxide or in electro-Fenton advanced oxidation treatment of water pollution.

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