Corrosion-resistant decomposition-promoting electrode for electric field composting and preparation method thereof

Abstract

The invention provides an electrode for corrosion-resistant decomposition-promoting electric field composting and a preparation method thereof.The electrode comprises an electrode body and a coating, the coating is formed on at least part of the surface of the electrode body, and the coating is formed on at least part of the surface of the electrode body; the coating comprises a conductive polymer / hydrophobic bio-based material composite material, a conductive agent and a binder, the conductive polymer comprises one or more of polyaniline, polyacetylene and polypyrrole, and the hydrophobic bio-based material comprises one or more of nanocellulose, beta-chitin and chitosan / polylactic acid. Therefore, by forming the coating comprising the conductive polymer / hydrophobic bio-based material composite material, the conductive agent and the binder on the electrode body, more breeding sites can be provided for microorganisms, and the corrosion resistance of the electrode and the electric field composting electron transmission efficiency are improved, so that the decomposition degree of compost can be improved, and the composting period can be shortened; and the seed germination rate of the obtained compost is increased by about 83.42% compared with that of a single compost.

Description

Technical Field

[0001] The invention belongs to the technical field of electric field composting, and particularly relates to a corrosion-resistant, ripening-promoting electrode for electric field composting and a preparation method thereof. Background Art

[0002] As one of the key technologies for resource-based organic waste treatment, aerobic composting has a long cycle, which significantly limits its efficiency. In recent years, electric field composting, a new approach to resource-based organic waste, has been shown to effectively improve the efficiency of traditional aerobic composting. Its core lies in the introduction of an electric field into the traditional aerobic composting process. Studies have shown that compared with traditional aerobic composting, electric field composting can significantly shorten the composting cycle and reduce overall greenhouse gas emissions.

[0003] As an emerging technology for resource utilization of organic waste, electric field composting shows broad application potential. However, in a composting environment rich in salt ions Cl-, organic acids (such as acetic acid, propionic acid) and microbial metabolites, electrochemical corrosion and microbial corrosion are prominent problems, leading to dissolution of the electrode surface, destruction of the passivation film and serious corrosion. Although the metal-based electrodes (such as carbon steel and stainless steel) widely used at present have good electrical conductivity and mechanical strength and are low in cost, they are susceptible to corrosion, and the corrosion products (such as Fe 2+ Cr 3+ ) may penetrate into the compost material, causing secondary pollution, which limits the agricultural application value of the compost product. Although electrodes such as carbon cloth have good chemical stability and strong resistance to biological corrosion, their resistivity increases and their current efficiency decreases under long-term high humidity environment and microbial attachment. In response to the above problems, researchers have proposed a variety of electrode protection strategies. By optimizing the electric field parameters during the composting process, such as current density and electric field strength, the corrosion rate of the electrode can be reduced, but the problem of electrode corrosion still exists. CN 112521190 A proposes a solution of setting bipolar membranes on both sides of the positive electrode to reduce electrode corrosion, but the bipolar membrane is expensive and complicated to operate. Therefore, it is particularly necessary to explore suitable and economical electrode protection measures. Summary of the Invention

[0004] The present invention aims to solve one of the technical problems in the related art at least to a certain extent.

[0005] In one aspect of the present invention, a corrosion-resistant, ripening-promoting electric field composting electrode is provided. According to an embodiment of the present invention, the electric field composting electrode comprises:

[0006] Electrode body;

[0007] A coating is formed on at least a portion of the surface of the electrode body, the coating comprising a conductive polymer / hydrophobic bio-based material composite, a conductive agent, and a binder, the conductive polymer comprising one or more of polyaniline, polyacetylene, and polypyrrole, and the hydrophobic bio-based material comprising one or more of nanocellulose, β-chitin, and chitosan / polylactic acid.

[0008] Therefore, the electrode for electric field composting of the present invention has a high bacterial load, corrosion resistance and electric field composting electron transmission efficiency, thereby improving the maturity of the compost and shortening the composting cycle.

[0009] In addition, the electric field composting electrode according to the above embodiment of the present invention may also have the following additional technical features:

[0010] In some embodiments of the present invention, the mass ratio of the conductive polymer / hydrophobic bio-based material composite material to the conductive agent and the binder is 6-8:1-2:1-2.

[0011] In some embodiments of the present invention, the conductive agent includes one or more of nanographene, acetylene black, biochar and carbon nanotubes.

[0012] In some embodiments of the present invention, the binder includes one or more of polytetrafluoroethylene, polyvinylidene fluoride, and perfluorosulfonic acid-based polymer.

[0013] In some embodiments of the present invention, the mass ratio of the conductive polymer to the hydrophobic bio-based material in the conductive polymer / hydrophobic bio-based material composite material is 1:(1-3).

[0014] In some embodiments of the present invention, the coating has a thickness of 1-5 mm.

[0015] In a second aspect of the present invention, a method for preparing a corrosion-resistant electrode for accelerating composting by electric field composting is provided. According to an embodiment of the present invention, the method comprises:

[0016] (1) mixing a hydrophobic bio-based material with an organic acid solution to obtain a hydrophobic bio-based material solution, wherein the hydrophobic bio-based material comprises one or more of nanocellulose, β-chitin, and chitosan / polylactic acid;

[0017] (2) mixing a conductive polymer precursor with an inorganic acid solution to obtain a conductive polymer precursor solution, wherein the conductive polymer precursor includes one or more of aniline, acetylene, and pyrrole;

[0018] (3) mixing the conductive polymer precursor solution and the hydrophobic bio-based material solution to obtain a mixed solution, placing the mixed solution in an ice water bath and adding dropwise an ammonium persulfate solution;

[0019] (4) adding alkaline solution dropwise to the solution obtained in step (3) to precipitate a conductive polymer / hydrophobic bio-based material composite material;

[0020] (5) grinding the conductive polymer / hydrophobic bio-based material composite material and mixing it with a conductive agent, a binder, and an organic alcohol;

[0021] (6) The mixed solution obtained in step (5) is applied to the surface of the electrode body, and dried to obtain a coated electrode.

[0022] In some embodiments of the present invention, in step (1), the mass ratio of the hydrophobic bio-based material to the organic acid solution is 1:(2-3), and the stirring time is 0.2-1 h.

[0023] In some embodiments of the present invention, in step (2), the mass ratio of the conductive polymer precursor to the inorganic acid solution is 1:(20-30).

[0024] In some embodiments of the present invention, the concentration of the inorganic acid solution is 2-3 mol.L -1 .

[0025] In some embodiments of the present invention, in step (3), the amount of the ammonium sulfate solution added is such that the mass ratio of the conductive polymer precursor solution to the ammonium sulfate solution is 1:1-3.

[0026] In some embodiments of the present invention, the concentration of the ammonium sulfate solution is 0.1-0.5 mol.L -1 .

[0027] In some embodiments of the present invention, in step (4), the amount of the alkali solution added is based on the pH of the system being 6.7-7.3.

[0028] In some embodiments of the present invention, the concentration of the alkali solution is 0.5-2 mol.L -1 , the dripping speed is 1-5 drops per second.

[0029] The electrodes in the electric field composting device of the present invention have a composite coating design including a conductive polymer (including one or more of polypyrrole, polyaniline and polyacetylene) and a hydrophobic bio-based material (one or more of nanocellulose, β-chitin and chitosan / polylactic acid), and cooperate with a conductive agent and a binder to construct an "electron transfer-hydrophobic protection-mechanical reinforcement" multifunctional electrode. The π-π conjugated structure of the conductive polymer significantly improves the electron transfer efficiency, the hydrophobic bio-based material enhances the mechanical properties through the hydrogen bond network, and effectively blocks the erosion of the compost liquid through the hydrophobic group; the conductive agent can optimize the microbial attachment interface and significantly increase the bacterial load. Therefore, the use of this electric field composting device breaks through the bottleneck of traditional composting efficiency, and the seed germination rate is increased by 83.42% compared with the traditional method. At the same time, the preparation process is simple, the performance is stable and controllable, and the service life of the electrode is increased. It has broad application prospects in the field of organic solid waste treatment. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] The above and / or additional aspects and advantages of the present invention will become apparent and readily understood from the following description of the embodiments with reference to the accompanying drawings, in which:

[0031] Figure 1 A schematic flow chart of a method for preparing an electric field composting electrode according to one embodiment of the present invention;

[0032] Figure 2 The curves showing the changes in seed germination rates during electric field composting in Examples 1-5 and the comparative example are shown.

[0033] Figure 3 This is the microbial distribution diagram of the comparative anode during the high temperature period;

[0034] Figure 4 This is the microbial distribution diagram of the anode during the high temperature period of Example 2. DETAILED DESCRIPTION

[0035] The following describes embodiments of the present invention in detail, examples of which are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements having the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are intended to be used to explain the present invention, and are not to be construed as limiting the present invention.

[0036] In one aspect, the present invention provides a corrosion-resistant, pro-maturity electric composting electrode. According to an embodiment of the present invention, the electric composting electrode includes an electrode body and a coating, the coating formed on at least a portion of the surface of the electrode body. The coating comprises a conductive polymer / hydrophobic bio-based material composite material, a conductive agent, and a binder. The conductive polymer comprises one or more of polyaniline, polyacetylene, and polypyrrole, and the hydrophobic bio-based material comprises one or more of nanocellulose, β-chitin, and chitosan / polylactic acid.

[0037] Thus, a coating comprising a conductive polymer / hydrophobic bio-based material composite material, a conductive agent, and a binder is formed on the electrode body. The conductive polymer constructs an electron transmission channel through a π-π conjugated structure, and the passivation film generated by its oxidation state can significantly reduce the corrosion current density. The hydrophobic bio-based material improves the mechanical strength and biocompatibility of the coating through a hydrogen bond network. The synergistic effect of the two significantly enhances the electrode stability. At the same time, the hydrophobic bio-based material including one or more of nanocellulose, β-chitin, and chitosan / polylactic acid can make the coating hydrophobic, thereby reducing the generated compost liquid from penetrating into the interior of the electrode body and corroding it. The conductive agent can further improve the electron transmission efficiency and provide an optimized attachment interface for microorganisms. The binder can form a gradient protective layer, allowing the electrode to maintain a high conductivity for a long time in a corrosive environment and significantly improve its wear resistance, thereby increasing the bacterial load, corrosion resistance, and electron transmission efficiency of electric field composting of the electrode, improving the maturity of the compost and shortening the composting cycle. In addition, the resulting compost increases seed germination by approximately 83.42% compared to using compost alone.

[0038] In some embodiments of the present invention, the coating comprises a conductive polymer / hydrophobic bio-based material composite material with a conductive agent and a binder in a mass ratio of 6-8:1-2:1-2. Forming this coating on the electrode body can further improve the electrode's bacterial load, corrosion resistance, and electron transfer efficiency during electric composting, thereby increasing compost maturity and shortening the composting cycle.

[0039] In some embodiments of the present invention, when the hydrophobic bio-based material is chitosan / polylactic acid, the mass ratio of chitosan to polylactic acid is 1:(1-3). This can further improve the bacterial load and corrosion resistance of the electrode, as well as the electron transfer efficiency of electric field composting, thereby increasing the maturity of the compost and shortening the composting cycle.

[0040] In some embodiments of the present invention, the conductive agent includes one or more of nanographene, biochar, carbon nanotubes and acetylene black; the binder includes one or more of polytetrafluoroethylene, polyvinylidene fluoride and perfluorosulfonic acid polymer.

[0041] In some embodiments of the present invention, the conductive polymer / hydrophobic bio-based material composite material has a mass ratio of the conductive polymer to the hydrophobic bio-based material of 1:(1-3). Thus, using this composite material can improve the bacterial load and corrosion resistance of the electrode, as well as the electron transfer efficiency of electric field composting, thereby increasing the maturity of the compost and shortening the composting cycle.

[0042] In some embodiments of the present invention, the coating has a thickness of 1-5 mm. Thus, by forming a coating of this thickness on the electrode body, the electrode's bacterial load, corrosion resistance, and electron transfer efficiency during electric composting can be further improved, thereby increasing the maturity of the compost and shortening the composting cycle.

[0043] In the second aspect of the present invention, the present invention provides a method for preparing an electrode for electric field composting. Figure 1 , the method comprising:

[0044] S1: Mixing hydrophobic bio-based materials with organic acid

[0045] In this step, a hydrophobic bio-based material is mixed with an organic acid solution to obtain a hydrophobic bio-based material solution, wherein the hydrophobic bio-based material includes one or more of nanocellulose, β-chitin and chitosan / polylactic acid, and the organic acid solution includes one or more of acetic acid and propionic acid. The mass ratio of the hydrophobic bio-based material to the organic acid solution is 1:(2-3), and the stirring time is 0.2-1h.

[0046] S2: Mixing the conductive polymer precursor with the inorganic acid solution

[0047] In this step, a conductive polymer precursor is mixed with an inorganic acid solution to obtain a conductive polymer precursor solution, wherein the conductive polymer precursor includes one or more of aniline, acetylene and pyrrole, and the inorganic acid solution includes one or more of hydrochloric acid solution and sulfuric acid solution. The mass ratio of the conductive polymer precursor to the inorganic acid solution is 1: (20-30), and the concentration of the inorganic acid solution is 2-3 mol.L -1 .

[0048] S3: Mix the conductive polymer precursor solution with the hydrophobic bio-based material solution to obtain a mixed solution, place the mixed solution in an ice water bath and dropwise add ammonium persulfate solution

[0049] In some embodiments of the present invention, the mixing ratio of the conductive polymer precursor solution and the hydrophobic bio-based material solution is carried out according to the mass ratio of the conductive polymer to the hydrophobic bio-based material of 1: (1-3), the amount of the ammonium sulfate solution added is carried out according to the mass ratio of the conductive polymer precursor solution to the ammonium sulfate solution of 1: 1-3, and the concentration of the ammonium sulfate solution is 0.1-0.5 mol.L -1 .

[0050] S4: Add alkali solution to the solution obtained in step S3 to precipitate the conductive polymer / hydrophobic bio-based material composite material

[0051] In this step, an alkali solution is added dropwise to the solution obtained in step S3 until the pH of the system is 6.7-7.3, thereby precipitating a conductive polymer / hydrophobic bio-based material composite material, wherein the alkali solution includes sodium hydroxide solution and alkali hydroxide.

[0052] Furthermore, the concentration of the alkali solution is 0.5-2 mol.L -1 , the dripping speed is 1-5 drops per second.

[0053] S5: Grind the conductive polymer / hydrophobic bio-based material composite material and mix it with the conductive agent, binder and organic alcohol

[0054] In this step, the conductive polymer / hydrophobic bio-based material composite material is ground and mixed with a conductive agent, a binder and an organic alcohol. The electrode for electric field composting is formed on the electrode body by forming a coating including the conductive polymer / hydrophobic bio-based material composite material, a conductive agent and a binder. The conductive polymer constructs an electron transmission channel and passivates the electrode surface. The hydrophobic bio-based material enhances the hydrophobicity, mechanical strength and biocompatibility of the coating. The conductive agent optimizes the conductive network, and the binder provides chemical inertness protection, thereby significantly improving the electrode bacterial load, corrosion resistance and electron transmission efficiency, improving the maturity of the compost and shortening the composting cycle. The mass ratio of the conductive polymer / hydrophobic bio-based material composite material to the conductive agent and the binder is (6-8): (1-2): (1-2), and the organic alcohol includes one or more of ethanol and propanol.

[0055] S6: applying the mixed solution obtained in step S5 to the surface of the electrode body, and drying to obtain a coated electrode.

[0056] Therefore, the method of the present invention can be used to prepare the above-mentioned electric field composting electrode with high bacterial load, corrosion resistance and electric field composting electron transmission efficiency, thereby improving the maturity of the compost and shortening the composting cycle.

[0057] In some embodiments of the present invention, an electric field composting device comprising an anode and a graphite cathode can include an anode and a graphite cathode, wherein the anode has a size of 20×60 cm, and a coating is formed on its surface comprising a conductive polymer / hydrophobic bio-based material composite material ground with nanographite, polytetrafluoroethylene and ethanol. A graphite rod is used as a reference electrode, an external voltage of 2V is applied, the pile material, organic solid waste, a leavening agent and water are mixed, and the moisture content of the mixture is adjusted to 60-70wt% and the carbon-nitrogen ratio is 20:1 to 25:1 to obtain compost raw materials. The compost raw materials are subjected to aerobic fermentation for 27 days. It is verified that the seed germination rate (GI) of the electric field composting of the present invention can reach the maturity standard 15 days after the composting is started.

[0058] It should be noted that the features and advantages described above for the electrode for electric field composting are also applicable to the method for preparing the electrode for electric field composting, and will not be described in detail here.

[0059] The examples described below are exemplary and are intended only to explain the present invention and are not to be construed as limiting the present invention. Where specific techniques or conditions are not specified in the examples, the methods or conditions described in the literature within the art or in the product specifications were used. Where the manufacturer of the reagents or instruments is not specified, all are commercially available conventional products.

[0060] Example 1

[0061] (1) dissolving nanocellulose in acetic acid (the mass ratio of nanocellulose to acetic acid is 1:2, and the stirring time is 0.5 h) to obtain a nanocellulose solution;

[0062] (2) dissolving aniline in hydrochloric acid (the mass ratio of aniline to hydrochloric acid is 1:20, and the concentration of hydrochloric acid is 0.5 mol / L) to obtain an aniline solution;

[0063] (3) After adding the aniline solution dropwise to the nanocellulose solution, the mixed solution was placed in an ice-water bath (the mixing ratio of the aniline solution to the nanocellulose solution was 1:1 by mass), and 40 ml of 0.5 mol / L ammonium persulfate solution was added dropwise;

[0064] (4) NaOH solution was added dropwise to the solution obtained in step (3) to adjust the pH of the system to 7 to precipitate the polyaniline / nanocellulose composite material (the concentration of the NaOH solution was 1 mol.L -1 , the dripping speed is 1 drop per second;

[0065] (5) The obtained polyaniline / nanocellulose composite material was ground into powder, fully mixed with nanographene and polytetrafluoroethylene in ethanol at a ratio of 8:1:1, and then coated on the surface of the carbon cloth of the electrode body (coating thickness is 2 mm), and dried to obtain a coated electrode.

[0066] Example 2

[0067] (1) dissolving nanocellulose in acetic acid (the mass ratio of nanocellulose to acetic acid is 1:2, and the stirring time is 0.5 h) to obtain a nanocellulose solution;

[0068] (2) dissolving aniline in hydrochloric acid (the mass ratio of aniline to hydrochloric acid is 1:20, and the concentration of hydrochloric acid is 0.5 mol / L) to obtain a polyaniline solution;

[0069] (3) After adding the aniline solution dropwise to the nanocellulose solution, the mixed solution was placed in an ice-water bath (the mixing ratio of the aniline solution to the nanocellulose solution was 1:2 by mass), and 40 ml of 0.5 mol / L ammonium persulfate solution was added dropwise;

[0070] (4) NaOH solution was added dropwise to the solution obtained in step (3) to adjust the pH of the system to 7 to precipitate the polyaniline / nanocellulose composite material (the concentration of the NaOH solution was 1 mol.L -1 , the dripping speed is 1 drop per second;

[0071] (5) The obtained polyaniline / nanocellulose composite material was ground into powder, mixed with nanographene and polytetrafluoroethylene in ethanol at a ratio of 8:1.5:1, and then coated on the surface of the carbon cloth of the electrode body (coating thickness is 2 mm), and dried to obtain a coated electrode.

[0072] Example 3

[0073] (1) dissolving nanocellulose in acetic acid (the mass ratio of nanocellulose to acetic acid is 1:2 and the stirring time is 0.5 h) to obtain a nanocellulose solution;

[0074] (2) dissolving aniline in hydrochloric acid (the mass ratio of aniline to hydrochloric acid is 1:20, and the concentration of hydrochloric acid is 0.5 mol / L) to obtain an aniline solution;

[0075] (3) After adding the aniline solution dropwise to the nanocellulose solution, the mixed solution was placed in an ice-water bath (the mixing ratio of the aniline solution to the nanocellulose solution was 1:3 by mass), and 40 ml of 0.5 mol / L ammonium persulfate solution was added dropwise;

[0076] (4) NaOH solution was added dropwise to the solution obtained in step (3) to adjust the pH of the system to 7 to precipitate the polyaniline / nanocellulose composite material (the concentration of the NaOH solution was 1 mol.L -1 , the dripping speed is 1 drop per second;

[0077] (5) The obtained polyaniline / nanocellulose composite material was ground into powder, mixed with nanographene and polytetrafluoroethylene in ethanol at a ratio of 8:2:1, and then coated on the surface of the carbon cloth of the electrode body (coating thickness is 2 mm), and dried to obtain a coated electrode.

[0078] Example 4

[0079] The method for preparing the electrode for electric field composting is the same as that in Example 2, except that the conductive polymer precursor aniline is replaced by acetylene, and the hydrophobic bio-based material nanocellulose is replaced by β-chitin.

[0080] Example 5

[0081] The method for preparing the electrode for electric field composting is the same as that in Example 2, except that the conductive polymer precursor aniline is replaced by pyrrole, the hydrophobic bio-based material nanocellulose is replaced by chitosan / polylactic acid, and the mass ratio of chitosan to polylactic acid is 1:1.

[0082] refer to Figure 1 , the coated electrodes obtained in the above Examples 1-5 were used as anodes respectively, with a size of 20×60 cm, and a graphite rod was used as a reference electrode, and an external voltage of 2V was applied. The pile materials (including pig manure and corn straw, wherein the pig manure was selected from a local large-scale farm in Beijing, and the corn straw was purchased from farmers around Beijing), organic solid waste, kitchen waste, and leavening agent straw were mixed with water. The carbon-nitrogen ratio of the compost material after mixing with the organic solid waste and leavening agent was 1:25, and the moisture content of the mixture was adjusted to 65wt%, and the C / N ratio was 20. The pile temperature, greenhouse gas emissions, etc. of each treatment group were tested every day, and samples were taken on the 0th day, 3rd day, 7th day, 11th day, 15th day, 21st day, and 27th day, respectively. Samples were taken from the upper, middle and lower areas of the pile, and after thorough mixing, the samples were stored in a refrigerator at 4°C. Saturated potassium chloride solution was used to extract fresh compost samples at a mass ratio of 10:1 to test the germination rate of Chinese cabbage seeds. The test curve is as follows Figure 2 As shown, the germination rate of the compost seeds in Example 2 on the 27th day can reach 230.45%.

[0083] Comparative Example

[0084] refer to Figure 1 , using carbon cloth as the anode with a size of 20×60cm, using graphite rod as the reference electrode, applying an external voltage of 2V, mixing the pile materials (including pig manure and corn straw, where pig manure is selected from local large-scale farms in Beijing, and corn straw is purchased from farmers around Beijing), organic solid waste, kitchen waste, and leavening agent straw with water, the carbon-nitrogen ratio of the compost material mixed with organic solid waste and leavening agent is 1:25, and the moisture content of the mixture is adjusted to 65wt%, and the C / N ratio is 20. The pile temperature, greenhouse gas emissions, etc. of each treatment group are tested every day, and samples are taken on the 0th, 3rd, 7th, 11th, 15th, 21st, and 27th days respectively. Samples are taken from the upper, middle, and lower areas of the pile, and after thorough mixing, the samples are stored in a refrigerator at 4°C. Saturated potassium chloride solution is used to extract fresh compost samples at a mass ratio of 10:1 to test the germination rate of Chinese cabbage seeds. The test curve is as follows Figure 2 As shown in the experimental results, the germination rate of seeds using compost on the 27th day was 119.49%. Figure 3 This is the microbial distribution diagram of the anode high temperature period of Comparative Example 2, Figure 4This is the microbial distribution diagram of the anode during the high-temperature period of Example 2. It can be seen that the bacterial load of Example 2 is significantly higher than that of the comparative example, which indicates that the composting electrode of the present application can improve the maturity of the compost and shorten the composting cycle.

[0085] The compost liquid obtained by composting for 3-7 days in Examples 1-5 and the comparative example was used as the medium, and then the same anodes as in Examples 1-5 and the comparative example were placed in the medium, and the open circuit potential (OCP) electrochemical impedance spectroscopy (EIS) and potentiodynamic polarization curve were measured respectively. The frequency range of the electrochemical impedance spectroscopy measurement was 10 -2 ~10 5 Hz, the AC signal amplitude was 5 mV, and the test results were fitted and analyzed using ZsimpoWin software. The polarization curve test scan rate was 1 mV / s, and the test range was ±250 mV of the self-corrosion potential. The test results are shown in Table 1.

[0086] Table 1

[0087] Comparative Example Example 1 Example 2 Example 3 Example 4 Example 5 Corrosion potential V -0.2431 -0.231 -0.006 -0.032 -0.072 -0.082

[0088] As can be seen from the data in Table 1, the corrosion potentials of the anodes of Examples 1-5 are all greater than the corrosion potential of the anode of the comparative example, indicating that the corrosion resistance of the anode can be significantly improved by forming the coating of the present invention on the anode body.

[0089] Although the embodiments of the present invention have been shown and described above, it will be understood that the above embodiments are illustrative and are not to be construed as limitations on the present invention. A person skilled in the art may change, modify, replace and modify the above embodiments within the scope of the present invention.

Claims

1. A corrosion-resistant electrode for accelerating composting in electric field, characterized in that: include: Electrode body; A coating is formed on at least a portion of the surface of the electrode body, the coating comprising a conductive polymer / hydrophobic bio-based material composite, a conductive agent, and a binder, the conductive polymer comprising one or more of polypyrrole, polyaniline, and polyacetylene, and the hydrophobic bio-based material comprising one or more of nanocellulose, β-chitin, and chitosan / polylactic acid.

2. The electrode according to claim 1, characterized in that The mass ratio of the conductive polymer / hydrophobic bio-based material composite material to the conductive agent and the binder is 6-8:1-2:1-2; Optionally, the conductive agent comprises one or more of nanographene, acetylene black, carbon nanotubes and biochar; Optionally, the binder includes one or more of polytetrafluoroethylene, polyvinylidene fluoride, and perfluorosulfonic acid-based polymer.

3. The electrode according to claim 1 or 2, characterized in that The mass ratio of the conductive polymer to the hydrophobic bio-based material in the conductive polymer / hydrophobic bio-based material composite material is 1:(1-3).

4. The electrode according to claim 1, characterized in that The thickness of the coating is 1-5 mm.

5. A method for preparing a corrosion-resistant electrode for accelerating composting in electric field composting, characterized in that: include: (1) mixing a hydrophobic bio-based material with an organic acid solution to obtain a hydrophobic bio-based material solution, wherein the hydrophobic bio-based material comprises one or more of nanocellulose, β-chitin, and chitosan / polylactic acid; (2) mixing a conductive polymer precursor with an inorganic acid solution to obtain a conductive polymer precursor solution, wherein the conductive polymer precursor includes one or more of aniline, acetylene, and pyrrole; (3) mixing the conductive polymer solution and the hydrophobic bio-based material solution to obtain a mixed solution, placing the mixed solution in an ice water bath and adding dropwise an ammonium persulfate solution; (4) adding alkaline solution dropwise to the solution obtained in step (3) to precipitate a conductive polymer / hydrophobic bio-based material composite material; (5) grinding the conductive polymer / hydrophobic bio-based material composite material and mixing it with a conductive agent, a binder, and an organic alcohol; (6) The mixed solution obtained in step (5) is applied to the surface of the electrode body, and dried to obtain a coated electrode.

6. The method according to claim 1, characterized in that In step (1), the mass ratio of the hydrophobic bio-based material to the organic acid solution is 1:(2-3), and the stirring time is 0.2-1h.

7. The method according to claim 1, characterized in that In step (2), the mass ratio of the conductive polymer precursor to the inorganic acid solution is 1:(20-30); Optionally, the concentration of the inorganic acid solution is 2-3 mol.L -1 .

8. The method according to claim 1, characterized in that In step (3), the amount of the ammonium sulfate solution added is carried out according to the mass ratio of the conductive polymer precursor solution to the ammonium sulfate solution of 1:1-3; Optionally, the concentration of the ammonium sulfate solution is 0.1-0.5 mol.L -1 .

9. The method according to claim 1, characterized in that In step (4), the amount of the alkali solution added is based on the pH of the system being 6.7-7.3; Optionally, the concentration of the alkali solution is 0.5-2 mol.L -1 , the dripping speed is 1-5 drops per second.

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