Preparation method and application of titanium-based electrode plate loaded with silicon-carbon nano composite material

Abstract

The invention relates to a preparation method and application of a titanium-based electrode plate loaded with a silicon-carbon nano composite material, and the preparation method comprises the following steps: tempering and balancing a carbon source, a silicon source and an organic solvent according to a mass ratio, reacting to obtain colloid, drying, and carbonizing under the protection of an inert atmosphere to obtain the silicon-carbon nano composite material; hardening and tempering the obtained silicon-carbon nano composite material, a conductive agent, a binder and an organic solvent according to a mass ratio in a balanced manner to form slurry, uniformly coating the surface of a pretreated titanium-based collector plate with the slurry, and then drying under the protection of an inert atmosphere to obtain a coated titanium-based electrode plate; the obtained coated titanium-based electrode plate is placed in a water bath for a water bath reaction, rare earth element modification is carried out, after modification is completed, cleaning and drying are sequentially carried out, and a finished product is obtained. The method has the advantages of reasonable preparation cost, high efficiency and low cost; the loaded silicon-carbon nano material is large in specific surface area, good in conductivity, good in chemical stability and easy to form; the catalytic activation effect is improved; the mechanical strength is high; and a preparation path is optimized.

Description

Technical Field

[0001] This invention belongs to the field of electrochemical material preparation technology, specifically relating to a method for preparing a titanium-based electrode plate supported on silicon-carbon nanocomposite materials, and also relating to its application. Background Technology

[0002] The aforementioned titanium-based electrode plate is a functional electrode constructed by using metallic titanium (Ti) or titanium alloys as the matrix (base / skeleton) and loading one or more layers of active coatings onto its surface. It is not simply a titanium plate, but a composite material system. The basic functions of the titanium-based electrode plate are mechanical support and conductive current collection, while the aforementioned coatings provide electrochemical activity (because titanium itself is inert). The main characteristics or advantages of titanium-based electrode plates include: excellent stability and long lifespan, excellent conductivity, high strength and light weight, and environmental friendliness (e.g., it can replace traditional lead electrodes and chromium-containing electrodes, reducing heavy metal pollution). Different coatings on titanium-based electrode plates result in different applications. In summary, the titanium-based electrode plate is a high-performance, long-life electrode that uses stable and corrosion-resistant titanium metal as its skeleton and is coated with different functional active materials to achieve efficient electrocatalysis, energy storage, degradation, and protection.

[0003] The aforementioned titanium-based electrode plates supported on silicon-carbon nanocomposites have a wide range of applications, such as oxygen evolution reaction, hydrogen evolution reaction, and redox reaction. In particular, titanium-based electrode plates supported on silicon-carbon nanocomposites, prepared through a reasonable process, have made significant contributions to the treatment of inert organic matter in catalytically activated desalination crystallization mother liquor (also known as "chemical high-salt wastewater desalination crystallization mother liquor").

[0004] As is known in the industry, after passing through a "zero-discharge system," high-salt chemical wastewater yields concentrated water with a total dissolved solids (TDS) mass fraction greater than 5%, which is difficult to treat biochemically. Taking coal chemical industry as an example, the concentrated water is further treated by a salt separation crystallization process to obtain recyclable by-product salts, namely sodium sulfate (Na2SO4) and sodium chloride (NaCl). The mother liquor produced by the salt separation crystallization process has a salt content greater than 20wt%, and is mixed with inert organic matter, calcium, magnesium, fluorine, silicon, nitrates, and other impurities. Currently, the common practice in the coal chemical industry is to evaporate and crystallize the mother liquor to produce mixed salts (i.e., hazardous waste, accounting for 15-25% of the total salt content). The cost of disposing of mixed salts is 2,000-3,000 yuan / ton, which imposes a significant economic burden on the owners.

[0005] The inert organic compounds remaining in the aforementioned mother liquor include nearly 40 kinds such as humin, fulvic acid, dimethylpyridine, acetophenone, acetone, glutaraldehyde, citric anhydride, methyl thiocyanate, and ethylacetamide. Because inert organic compounds are soluble in high-salt wastewater, they are characterized by complex composition, small relative molecular weight (generally less than 150 Da), high biotoxicity, and difficulty in degradation, making their removal using conventional technologies very difficult.

[0006] Silicon-carbon nanocomposites refer to materials in which at least one dimension of the dispersed phase is less than 100 nm. On the one hand, nanomaterials have a high surface-to-volume ratio, thus exhibiting high chemical activity. On the other hand, taking nanowires as an example, they have a high aspect ratio, and particle transport in one dimension is unconstrained, which is beneficial for technological applications.

[0007] The controllable synthesis of silicon-carbon nanocomposites, the catalytic activation effect of inert organic matter, and the functional design and rare earth modification research based on nanomaterials have become the prerequisites and guarantees for the practical application of related materials.

[0008] Due to the high salt content of the mother liquor from salt crystallization, existing processes for removing inert organic matter from it are not ideal. Mainstream processes, such as the combination of ozone oxidation and activated carbon adsorption, only achieve a removal rate of about 30% for inert organic matter. Another example is the combination of electrochemical oxidation and macroporous resin adsorption, which suffers from safety concerns. Because the mother liquor contains a significant amount of sodium chloride (typically NaCl > 10 wt%), hydrogen (H2) and chlorine (Cl2) are generated at the cathode and anode respectively after electrolysis. If these gases are not separated and collected promptly, it can lead to chlorine poisoning or even an explosion of the mixed gases.

[0009] Traditional electrochemical technology has gradually become a means of removing organic matter from wastewater with low salinity (TDS < 15000 mg / L) due to its strong oxidizing ability, modular design, and environmental compatibility. However, it is not suitable for high salinity environments. One reason is the safety issues that may be caused by hydrogen and chlorine evolution, as mentioned above, and the other is the issues of corrosion resistance and performance degradation.

[0010] In traditional electrochemistry, the input DC current is typically 500-2500A. For example, in this experiment, a titanium-based nickel-cobalt oxide (Ti / Ni-Co-O) electrode was used to test its corrosion resistance during the treatment of high-salt wastewater, and the reasons for the electrode's performance degradation were analyzed. In high-salt wastewater (NaCl + Na2SO4 solution) with a TDS of 200,000 mg / L, experiments were conducted at pH 4 and pH 11. After electrolysis for several hours at a current density of 200 mA·cm^(-2), atomic absorption spectrophotometry confirmed the presence of nickel and cobalt ions. When the titanium-based ruthenium-iridium oxide (Ti / Ru-Ir-O) electrode was used, atomic absorption spectrophotometry also confirmed the presence of ruthenium and iridium ions, but at 13-16% lower levels than nickel and cobalt ions.

[0011] Experimental results show that: ① Nickel-cobalt oxides dissolve faster than ruthenium-iridium oxides in both acidic and alkaline solutions; ② Chlorine and oxygen evolution is the root cause of the corrosion of the transition metal coating due to its chlorine and oxygen evolution.

[0012] Regarding the aforementioned characteristics of the mother liquor, the corrosion resistance of the electrode plate, and the performance degradation phenomenon, there have been no reports to date on the application of silicon-carbon nanomaterials in the catalytic degradation of inert organic matter in the mother liquor. This is because the preparation process is relatively complicated, the functional design is difficult, and there are problems such as hydrogen evolution, chlorine evolution, and oxygen evolution.

[0013] Therefore, it is of positive significance to explore effective methods for preparing silicon-carbon nanomaterials by catalyzing and activating inert organic matter in the mother liquor of salt crystallization. However, simplifying the process, reducing costs, and improving efficiency are urgent problems to be solved. The technical solution to be introduced below is generated in this context. Summary of the Invention

[0014] The objective of this invention is to provide a method for preparing a titanium-based electrode plate loaded with silicon-carbon nanocomposite materials. This method has the advantages of a short process flow, low preparation cost, high preparation efficiency, excellent mechanical strength of the prepared titanium-based electrode plate, large specific surface area and good electrical conductivity of the loaded silicon-carbon nanocomposite materials, good chemical stability and easy molding.

[0015] Another objective of this invention is to provide an application of a titanium-based electrode plate loaded with silicon-carbon nanocomposite materials, which can fulfill specific uses.

[0016] The objective of this invention is achieved by providing a method for preparing a titanium-based electrode plate supported on silicon-carbon nanocomposite materials, comprising the following steps:

[0017] (1) To prepare silicon-carbon nanocomposite material, carbon source, silicon source and organic solvent are adjusted and balanced according to mass ratio and reacted to obtain colloid. After drying, carbonization is carried out under inert atmosphere to obtain silicon-carbon nanocomposite material.

[0018] (2) Prepare a coated titanium-based electrode plate. The silicon-carbon nanocomposite material obtained in step (1) is mixed with conductive agent, binder and organic solvent in a mass ratio to form a slurry. The slurry is then uniformly coated on the surface of the pretreated titanium-based current collector and then dried under an inert atmosphere to obtain a coated titanium-based electrode plate.

[0019] (3) Prepare a titanium-based electrode plate loaded with silicon-carbon nanocomposite material. Place the coated titanium-based electrode plate obtained in step (2) in a water bath for water bath reaction and rare earth element modification. After the modification is completed, clean and dry in sequence to obtain a titanium-based electrode plate loaded with silicon-carbon nanocomposite material.

[0020] In a specific embodiment of the present invention, the mass ratio of the carbon source, silicon source and organic solvent in step (1) is 1:(1-1.5):(3-5); the carbon source is liquid phenolic resin, liquid urea-formaldehyde resin or liquid melamine resin; the silicon source, calculated as SiO2, is any one or two of methylchlorosilane, phenylchlorosilane, methyl vinylchlorosilane, ethyl trichlorosilane, propyl trichlorosilane, vinyl trichlorosilane, γ-chloropropyl trichlorosilane; the organic solvent is any one or two of toluene, nitrobenzene, pyridine, 4-methyl-2-pentanone; the conditioning and homogenization is achieved by dissolving and homogenizing under stirring or ultrasonic dispersion conditions, the stirring speed is 400-600 r / min, and the ultrasonic dispersion uses an ultrasonic emulsifier with an ultrasonic frequency of 80-120 kHz.

[0021] In another specific embodiment of the present invention, the reaction in step (1) is carried out under normal pressure, at a reaction temperature of 60-80°C, and for a reaction time of 2-4 hours. The pH of the reaction is adjusted to 14 using a 30% sodium hydroxide aqueous solution. The drying is carried out in a nitrogen-filled oven at 80-100°C until the moisture content is less than 3%. The inert atmosphere is a nitrogen atmosphere or an argon atmosphere. The carbonization is carried out using a calcination furnace, which is a rotary atmosphere furnace, a rotary calcination furnace, or an electric drum furnace. The carbonization time is 6 hours, the carbonization temperature is 800-1200°C, and the heating rate is 5°C / min.

[0022] In another specific embodiment of the present invention, the mass ratio of the silicon-carbon nanocomposite material to the conductive agent, binder and organic solvent in step (2) is 1:0.1:0.1:(3-4); the conductive agent is SUPER-P, acetylene black, Ketjen black, graphite-KS or graphene; the binder is polyvinylidene fluoride, sodium carboxymethyl cellulose, polyacrylic acid or styrene-butadiene rubber; the organic solvent is N,N-dimethylacetamide, N-methylformamide, dimethyl sulfoxide, N,N-dimethylaniline or formamide; the conditioning and homogenization is to dissolve and homogenize to form a slurry under normal temperature and pressure, stirring or ultrasonic dispersion conditions.

[0023] In another specific embodiment of the present invention, the drying in step (2) involves placing the titanium-based manifold coated with slurry in a vacuum oven at 45°C and drying it under normal pressure and vacuum conditions for 4 hours. After cooling, it is removed, coated again, and dried, and this process is repeated 3 times. The thickness of the uniformly coated layer is 100-200 μm. The inert atmosphere is a protective gas environment formed by nitrogen or argon. The drying under the inert atmosphere protection is carried out in a nitrogen-filled oven at 60-80°C until the moisture content is less than 1%. The conditioning and equalization stirring is carried out at room temperature and pressure. The stirring is performed using magnetic force at a stirring rate of 400-600 r / min; the ultrasonic dispersion is carried out at room temperature and pressure using an ultrasonic emulsifier with an ultrasonic frequency of 80-120 kHz; the pretreatment of the titanium-based manifold is as follows: first, it is placed in a 1 mol / L sodium hydroxide (NaOH) aqueous solution at 80°C for 2 hours to remove surface oil stains; then, the surface is washed with deionized water to remove residual alkali; next, it is placed in a 2 mol / L oxalic acid (H2C2O4) aqueous solution at 80°C for 2 hours to remove the oxide film on the surface of the titanium-based manifold; finally, the surface is repeatedly rinsed with deionized water until neutral.

[0024] In another specific embodiment of the present invention, the water bath in step (3) is a constant temperature water bath, the pH value is adjusted to 7-9, and deionized water is used; the water bath reaction is a constant temperature shaking soaking reaction at 90-100℃, and the reaction time is 4-6h; the substance containing rare earth elements is a rare earth compound, and the rare earth compound is a soluble rare earth salt; the washing is done with deionized water until neutral; the drying is done with an electric heating blower drying oven, the heating rate is controlled at 1-3℃ / min, and drying is carried out at below 60℃ until the moisture content is less than 1%.

[0025] In a further specific embodiment of the present invention, the soluble rare earth salt is a rare earth chloride, a rare earth nitrate, or a rare earth sulfate.

[0026] In a further specific embodiment of the present invention, the rare earth chloride is a single rare earth salt, which is lanthanum chloride, cerium chloride, praseodymium chloride, neodymium chloride, promethium chloride, yttrium chloride, or scandium chloride. The aqueous solution of the rare earth chloride has a mass fraction of 1% at room temperature (25°C) and a pH value of 7-9. The rare earth nitrate is a single rare earth salt, which is lanthanum nitrate, cerium nitrate, praseodymium nitrate, neodymium nitrate, promethium nitrate, yttrium nitrate, or scandium nitrate. The rare earth nitrate aqueous solution has a mass fraction of 1% at room temperature (25°C) and a pH value of 7-9. The liquid has a mass fraction of 1% at room temperature (25℃) and a pH value of 7-9; the rare earth sulfate is a single rare earth salt, which is lanthanum sulfate, cerium sulfate, praseodymium sulfate, neodymium sulfate, yttrium sulfate, or scandium sulfate, and the rare earth sulfate aqueous solution has a mass fraction of 1% at room temperature (25℃) and a pH value of 7-9; the drying is carried out in an electric heating forced-air drying oven, with the heating rate controlled at 1-3℃ / min, and drying is carried out at 60-100℃ until the moisture content is less than 1%.

[0027] Another objective of this invention is achieved by providing a titanium-based electrode plate loaded with silicon-carbon nanocomposite material, used as a micro-field positive and negative electrode plate for the catalytic activation of inert organic matter in the mother liquor of high-salt chemical wastewater desalination crystallization.

[0028] In yet another specific embodiment of the present invention, the micro-electric field is specifically designed for micro-current applications with a current of less than 1 mA for the catalytic activation of inert organic compounds, wherein the input DC current density is 0.1-0.3 mA·cm^(-2) and the voltage is 1-2.5 V.

[0029] The technical solution provided by this invention has the following advantages: (1) The raw materials are widely available, the process flow is short, the preparation cost is reasonable and controllable, and the preparation efficiency is high, thus achieving a low-cost effect; (2) The supported silicon-carbon nanomaterials have a large specific surface area, good electrical conductivity, good chemical stability, and are easy to mold; (3) Rare earth modification optimizes the compatibility of nanomaterials and helps to significantly improve the catalytic activation effect; (4) The selection of titanium-based current collectors is beneficial to improving the mechanical strength of the product; (5) The preparation path is optimized by comprehensively considering the application characteristics, providing technical support for specific applications. Detailed Implementation

[0030] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to specific embodiments. However, it should be understood that the description herein is merely illustrative and is not intended to limit the scope of the invention.

[0031] Unless otherwise defined, all technical and scientific terms used in the embodiments have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains; that is, the terminology used is for the purpose of describing particular embodiments only and is not intended to limit the invention. The characterization methods involved in the embodiments can be found in relevant descriptions in the prior art, and will not be repeated herein.

[0032] Example 1:

[0033] A method for preparing a titanium-based electrode plate supported on silicon-carbon nanocomposite materials includes the following steps:

[0034] (1) Preparation of silicon-carbon nanocomposite materials: Carbon source, silicon source, and organic solvent are mixed and homogenized at a mass ratio of 1:1:3 and reacted to obtain a colloid. After drying, the colloid is carbonized under an inert atmosphere to obtain silicon-carbon nanocomposite materials. The carbon source in this step is liquid phenolic resin, and the silicon source, calculated as SiO2, is methylchlorosilane. The organic solvent is toluene. The homogenization is achieved by dissolving and homogenizing under magnetic stirring at a speed of 400 r / min or 600 r / min. The reaction is carried out under normal pressure and the reaction temperature is... The reaction is carried out at 80℃ or 60℃ for 4 hours or 2 hours. The pH of the reaction is adjusted to 14 using a 30% (mass percentage) NaOH aqueous solution. The drying is performed in a nitrogen-filled oven at 80℃ until the moisture content is 2.5%. The inert atmosphere is a protective gas environment of nitrogen with a purity of 99.99%. The carbonization is carried out in a calcination furnace, which is a rotary atmosphere furnace. The carbonization time is 6 hours, the carbonization temperature is 800℃, and the heating rate is 5℃ / min.

[0035] (2) Preparation of coated titanium-based electrode plate: The silicon-carbon nanocomposite material obtained in step (1) is mixed with a conductive agent, a binder, and an organic solvent in a mass ratio of 1:0.1:0.1:3 to form a slurry. The slurry is then uniformly coated onto the surface of a pretreated titanium-based current collector and dried under an inert atmosphere to obtain the coated titanium-based electrode plate. The conductive agent in this step is SUPER-P, the binder is polyvinylidene fluoride, and the organic solvent is N,N-dimethylacetamide. The conditioning and equalization are carried out at room temperature and pressure and under stirring conditions to dissolve and homogenize the slurry. The stirring is done with magnetic stirring at a speed of 400 r / min. The drying is carried out by placing the titanium-based current collector coated with the slurry in a vacuum oven at 45°C and drying it under normal pressure and vacuum conditions for 4 hours. The process is repeated three times, meaning the slurry is applied three times. After each application, the surface is dried, cooled, and then coated again. This process is repeated three times, resulting in a uniform coating thickness of 100-200 μm. The inert atmosphere is a protective gas environment formed by nitrogen, with a nitrogen purity >99.99%. Drying under the inert atmosphere is performed in a nitrogen-filled oven at 60°C until the moisture content reaches 1%. The pretreatment of the titanium-based current collector involves bathing it in a 1 mol / L caustic soda (NaOH) aqueous solution at 80°C for 2 hours to remove surface oil, followed by rinsing with deionized water to remove residual alkali. Then, it is bathed in a 2 mol / L oxalic acid (H2C2O4) aqueous solution at 80°C for 2 hours to remove the oxide film on the surface of the titanium-based current collector. Finally, the surface is repeatedly rinsed with deionized water until neutral.

[0036] (3) Prepare a titanium-based electrode plate loaded with silicon-carbon nanocomposite material. Place the coated titanium-based electrode plate obtained in step (2) in a water bath for water bath reaction and rare earth element modification. After the modification is completed, wash and dry in sequence to obtain a titanium-based electrode plate loaded with silicon-carbon nanocomposite material. The water bath mentioned in this step is a constant temperature water bath. The pH value is adjusted to pH=7. The washing is done with deionized water. The water bath reaction is a constant temperature shaking soaking reaction at 90℃ for 6 hours. The rare earth element is a single rare earth salt of chloride, specifically lanthanum chloride. The mass fraction of lanthanum chloride aqueous solution at room temperature (25℃) is 1%, and the pH value is 7. The washing is done with deionized water until neutral. The drying is done with an electric heating blast drying oven, with the heating rate controlled at 1℃ / min, and dried at 60℃ until the moisture content is 1%.

[0037] Example 2:

[0038] A method for preparing a titanium-based electrode plate supported on silicon-carbon nanocomposite materials includes the following steps:

[0039] (1) Preparation of silicon-carbon nanocomposite materials: Carbon source, silicon source, and organic solvent are mixed in a mass ratio of 1:1.2:4, conditioned and homogenized to obtain a colloid. After drying, the colloid is carbonized under an inert atmosphere to obtain silicon-carbon nanocomposite materials. The carbon source in this step is liquid melamine resin, the silicon source is phenylchlorosilane (SiO2), and the organic solvent is pyridine. The conditioning and homogenization are carried out under ultrasonic dispersion conditions to achieve homogenization. Ultrasonic dispersion is performed using an ultrasonic emulsifier with an ultrasonic frequency of 80 kHz. The reaction is carried out under normal pressure. The reaction temperature was 70℃, the reaction time was 3h, and the pH was adjusted to 14 using a 30% (i.e., 30% by mass) NaOH aqueous solution. The drying was carried out in a nitrogen-filled oven at 90℃ until the moisture content was 3%. The inert atmosphere was a protective gas environment of argon with a purity of 99.99%. The carbonization was carried out in a rotary kiln for 6h, at a carbonization temperature of 1000℃, and with a heating rate of 5℃ / min.

[0040] (2) Preparation of coated titanium-based electrode plate: The silicon-carbon nanocomposite material obtained in step (1) is mixed with a conductive agent, a binder, and an organic solvent in a mass ratio of 1:0.1:0.1:3.5 to form a slurry. The slurry is then uniformly coated onto the surface of the pretreated titanium-based current collector and dried under an inert atmosphere to obtain the coated titanium-based electrode plate. The conductive agent in this step is acetylene black, the binder is sodium carboxymethyl cellulose, and the organic solvent is N-methylformamide. The conditioning and equalization is carried out at room temperature and pressure and under ultrasonic dispersion conditions to dissolve and homogenize the slurry. An ultrasonic emulsifier with an ultrasonic frequency of 100 Hz is used. The drying is carried out by placing the titanium-based current collector coated with the slurry in a vacuum oven at 45°C and drying it under normal pressure and vacuum conditions for 4 hours, and repeating the process. The coating process involves three applications of the slurry. After each application, the coating is dried, cooled, and then applied again, followed by another drying cycle. This process is repeated three times to achieve a uniform coating thickness of 100-200 μm. The inert atmosphere is a protective gas environment formed by argon, with an argon purity >99.99%. Drying under the inert atmosphere is performed in a nitrogen-filled oven at 70°C until the moisture content reaches 0.5%. The pretreatment of the titanium-based current collector involves bathing it in a 1 mol / L sodium hydroxide (NaOH) aqueous solution at 80°C for 2 hours to remove surface oil. The surface is then washed with deionized water to remove any residual alkali. Subsequently, the surface is bathed in a 2 mol / L oxalic acid (H2C2O4) aqueous solution at 80°C for 2 hours to remove the oxide film. Finally, the surface is repeatedly rinsed with deionized water until neutral.

[0041] (3) Prepare a titanium-based electrode plate loaded with silicon-carbon nanocomposite material. Place the coated titanium-based electrode plate obtained in step (2) in a water bath for water bath reaction and rare earth element modification. After the modification is completed, wash and dry in sequence to obtain a titanium-based electrode plate loaded with silicon-carbon nanocomposite material. The water bath mentioned in this step is a constant temperature water bath. The pH value is adjusted to pH=8. The washing is done with deionized water. The water bath reaction is a constant temperature shaking soaking reaction at 95℃ for 5 hours. The rare earth element is a single rare earth salt of nitrate, specifically cerium nitrate. The mass fraction of cerium nitrate aqueous solution at room temperature (25℃) is 1%, and the pH value is 8. The washing is done with deionized water until neutral. The drying is done with an electric heating blast drying oven, with the heating rate controlled at 2℃ / min, and dried at 80℃ until the moisture content is 1%.

[0042] Example 3:

[0043] A method for preparing a titanium-based electrode plate supported on silicon-carbon nanocomposite materials includes the following steps:

[0044] (1) Preparation of silicon-carbon nanocomposite material: The carbon source, silicon source, and organic solvent are mixed in a mass ratio of 1:1.5:5, conditioned and homogenized to obtain a colloid. After drying, the colloid is carbonized under an inert atmosphere to obtain the silicon-carbon nanocomposite material. The carbon source referred to in this step is liquid urea-formaldehyde resin. The silicon source, calculated as SiO2, is a mixture of methyl vinylchlorosilane and ethyl trichlorosilane in any weight ratio. The organic solvent is a mixture of 4-methyl-2-pentanone and nitrobenzene. The conditioning and homogenization are achieved by dissolving and homogenizing under ultrasonic dispersion conditions. The ultrasonic dispersion uses an ultrasonic frequency of 120 kHz. The emulsifying disperser is used in the reaction, which is carried out under normal pressure at a temperature of 80°C for 3.5 hours. The pH of the reaction is adjusted to 14 using a 30% (mass percentage) NaOH aqueous solution. The drying is performed in a nitrogen-filled oven at 100°C until the moisture content is 1%. The inert atmosphere is a protective gas environment of nitrogen with a purity of 99.99%. The carbonization is carried out in a calcining furnace, which is an electrically heated drum furnace. The carbonization time is 6 hours, the carbonization temperature is 1200°C, and the heating rate is 5°C / min.

[0045] (2) Preparation of coated titanium-based electrode plate: The silicon-carbon nanocomposite material obtained in step (1) is mixed with a conductive agent, a binder, and an organic solvent in a mass ratio of 1:0.1:0.1:4 to form a slurry. The slurry is then uniformly coated onto the surface of the pretreated titanium-based current collector and dried under an inert atmosphere to obtain the coated titanium-based electrode plate. The conductive agent in this step is graphite-KS, the binder is polyacrylic acid, and the organic solvent is N,N-dimethylaniline. The conditioning and equalization is carried out at room temperature and pressure and under ultrasonic dispersion conditions to dissolve and homogenize the slurry. An ultrasonic emulsifier with an ultrasonic frequency of 120Hz is used. The drying is carried out by placing the titanium-based current collector coated with the slurry in a vacuum oven at 45°C and drying it for 4 hours under normal pressure and vacuum conditions, and repeating the process. The coating process involves three applications of the slurry, each followed by drying and cooling before recoating and drying. This cycle is repeated three times, resulting in a uniform coating thickness of 100-200 μm. The inert atmosphere is a protective gas environment formed by nitrogen, with a nitrogen purity >99.99%. Drying under this inert atmosphere is performed in a nitrogen-filled oven at 80°C until the moisture content reaches 0.2%. The pretreatment of the titanium-based current collector involves bathing it in a 1 mol / L sodium hydroxide (NaOH) aqueous solution at 80°C for 2 hours to remove surface oil, followed by rinsing with deionized water to remove residual alkali. Then, it is bathed in a 2 mol / L oxalic acid (H2C2O4) aqueous solution at 80°C for 2 hours to remove the oxide film on the surface of the titanium-based current collector. Finally, the surface is repeatedly rinsed with deionized water until neutral.

[0046] (3) Prepare a titanium-based electrode plate loaded with silicon-carbon nanocomposite material. Place the coated titanium-based electrode plate obtained in step (2) in a water bath for water bath reaction and rare earth element modification. After the modification is completed, wash and dry in sequence to obtain a titanium-based electrode plate loaded with silicon-carbon nanocomposite material. The water bath mentioned in this step is a constant temperature water bath. The pH value is adjusted to pH=9. The washing is done with deionized water. The water bath reaction is a constant temperature shaking soaking reaction at 100℃ for 4 hours. The rare earth element is a single rare earth salt of sulfate, specifically yttrium sulfate. The mass fraction of yttrium sulfate aqueous solution at room temperature (25℃) is 1%, and the pH value is 9. The washing is done with deionized water until neutral. The drying is done with an electric heating blast drying oven, with the heating rate controlled at 3℃ / min, and dried at 100℃ until the moisture content is 1%.

[0047] Application example:

[0048] The titanium-based electrode plates loaded with silicon-carbon nanocomposite materials obtained in Examples 1 to 3, used as positive and negative electrode plates in the micro-electric field for catalytic activation of inert organic matter in the mother liquor of high-salt wastewater desalination crystallization in coal chemical industry, have good mechanical strength and high corrosion resistance. Under harsh conditions such as maximum power (current density of 1 mA·cm^(-2) and voltage of 2.5 V) and maximum salt content (TDS = 300000 mg / L), they still maintain reliable chemical stability and catalytic activation effect after continuous operation for 30 days in the micro-electric field.

[0049] The main water quality data of the aforementioned mother liquor for desalination and crystallization of high-salt wastewater from a coal chemical plant (i.e., "crystallization mother liquor") are as follows: inert organic matter (inert COD) is 11200 mg / L, TDS is 205600 mg / L, total hardness (calculated as CaCO3) is 1330 mg / L, potassium ions are 3470 mg / L, nitrate is 4730 mg / L, chloride ions are 70840 mg / L, sulfate ions are 49600 mg / L, pH value is 12.7, and total silicon (calculated as SiO2) is 477 mg / L.

[0050] The water quality of the mother liquor from the desalination and crystallization of wastewater from a certain coal chemical plant is characterized by the presence of inert COD and Na. + K + Ca 2+ Mg 2+ NO3 - Cl - SO4 2- For complex systems like these, the key to realizing the resource utilization of mother liquor lies in removing organic impurities (inert COD).

[0051] The titanium-based electrode plates loaded with silicon-carbon nanocomposite materials prepared in Examples 1 to 3 above have the technical effects shown in the table below for treating the mother liquor of high-salt wastewater crystallization from a certain coal chemical industry.

[0052]

[0053] The above description is only a preferred embodiment of the present invention. It should be noted that those skilled in the art can make several improvements and modifications without departing from the principle of the present invention, and these improvements and modifications should also be considered within the scope of protection of the present invention.

Claims

1. A method for preparing a titanium-based electrode plate supported on silicon-carbon nanocomposite materials, characterized in that: Includes the following steps: (1) To prepare silicon-carbon nanocomposite material, carbon source, silicon source and organic solvent are adjusted and balanced according to mass ratio and reacted to obtain colloid. After drying, carbonization is carried out under inert atmosphere to obtain silicon-carbon nanocomposite material. (2) Prepare a coated titanium-based electrode plate. The silicon-carbon nanocomposite material obtained in step (1) is mixed with conductive agent, binder and organic solvent in a mass ratio to form a slurry. The slurry is then uniformly coated on the surface of the pretreated titanium-based current collector and then dried under an inert atmosphere to obtain a coated titanium-based electrode plate. (3) Prepare a titanium-based electrode plate loaded with silicon-carbon nanocomposite material. Place the coated titanium-based electrode plate obtained in step (2) in a water bath for water bath reaction and rare earth element modification. After the modification is completed, clean and dry in sequence to obtain a titanium-based electrode plate loaded with silicon-carbon nanocomposite material.

2. The method for preparing the titanium-based electrode plate supported on silicon-carbon nanocomposite material according to claim 1, characterized in that: The mass ratio of the carbon source, silicon source, and organic solvent in step (1) is 1:1-1.5:3-5; the carbon source is liquid phenolic resin, liquid urea-formaldehyde resin, or liquid melamine resin; the silicon source, calculated as SiO2, is any one or two of methylchlorosilane, phenylchlorosilane, methyl vinylchlorosilane, ethyl trichlorosilane, propyl trichlorosilane, vinyl trichlorosilane, and γ-chloropropyl trichlorosilane; the organic solvent is any one or two of toluene, nitrobenzene, pyridine, and 4-methyl-2-pentanone; the conditioning and homogenization is achieved by dissolving and homogenizing under stirring or ultrasonic dispersion conditions, the stirring speed is 400-600 r / min, and the ultrasonic dispersion uses an ultrasonic emulsifier with an ultrasonic frequency of 80-120 kHz.

3. The method for preparing the titanium-based electrode plate supported on silicon-carbon nanocomposite material according to claim 1, characterized in that: The reaction described in step (1) is carried out under normal pressure, at a reaction temperature of 60-80℃, and for a reaction time of 2-4 hours. The pH of the reaction is adjusted to 14 using a 30% sodium hydroxide aqueous solution. The drying is carried out in a nitrogen-filled oven at 80-100℃ until the moisture content is less than 3%. The inert atmosphere is a nitrogen atmosphere or an argon atmosphere. The carbonization is carried out in a calcining furnace, which is a rotary atmosphere furnace, a rotary calcining furnace, or an electric drum furnace. The carbonization time is 6 hours, the carbonization temperature is 800-1200℃, and the heating rate is 5℃ / min.

4. The method for preparing the titanium-based electrode plate supported on silicon-carbon nanocomposite material according to claim 1, characterized in that: In step (2), the mass ratio of the silicon-carbon nanocomposite material to the conductive agent, binder, and organic solvent is 1:0.1:0.1:3-4; the conductive agent is SUPER-P, acetylene black, Ketjen black, graphite-KS, or graphene; the binder is polyvinylidene fluoride, sodium carboxymethyl cellulose, polyacrylic acid, or styrene-butadiene rubber; the organic solvent is N,N-dimethylacetamide, N-methylformamide, dimethyl sulfoxide, N,N-dimethylaniline, or formamide; the conditioning and homogenization is performed under ambient temperature and pressure, stirring, or ultrasonic dispersion conditions to dissolve and homogenize the material to form a slurry.

5. The method for preparing the titanium-based electrode plate supported on silicon-carbon nanocomposite material according to claim 1, characterized in that: The drying process in step (2) involves placing the titanium-based manifold coated with slurry in a vacuum oven at 45°C and drying it under normal pressure and vacuum for 4 hours. After cooling, it is removed, coated again, and dried, repeating this process three times. The uniform coating thickness is 100-200 μm. The inert atmosphere is a protective gas environment formed by nitrogen or argon. The drying under the inert atmosphere is carried out in a nitrogen-filled oven at 60-80°C until the moisture content is less than 1%. The conditioning and equalization stirring is carried out at room temperature and pressure using... Magnetic stirring is used at a stirring rate of 400-600 r / min; ultrasonic dispersion is performed at room temperature and pressure using an ultrasonic emulsifier with an ultrasonic frequency of 80-120 kHz; the pretreatment of the titanium-based manifold involves first bathing it in a 1 mol / L caustic soda aqueous solution at 80°C for 2 hours to remove surface oil, then washing away residual alkali with deionized water, followed by bathing it in a 2 mol / L oxalic acid aqueous solution at 80°C for 2 hours to remove the oxide film on the surface of the titanium-based manifold, and finally rinsing the surface repeatedly with deionized water until neutral.

6. The method for preparing the titanium-based electrode plate supported on silicon-carbon nanocomposite material according to claim 1, characterized in that: The water bath in step (3) is a constant temperature water bath with a pH value adjusted to 7-9 and deionized water used; the water bath reaction is a constant temperature shaking soaking reaction at 90-100℃ for 4-6 hours; the rare earth element-containing substance is a rare earth compound, which is a soluble rare earth salt; the cleaning is done with deionized water until neutral; the drying is done in an electric heating forced-air drying oven with a heating rate controlled at 1-3℃ / min, and drying is carried out at below 60℃ until the moisture content is less than 1%.

7. The method for preparing the titanium-based electrode plate supported on silicon-carbon nanocomposite material according to claim 6, characterized in that: The soluble rare earth salts mentioned are rare earth chlorides, rare earth nitrates, or rare earth sulfates.

8. The method for preparing the titanium-based electrode plate supported on silicon-carbon nanocomposite material according to claim 7, characterized in that: The rare earth chloride is a single rare earth salt, such as lanthanum chloride, cerium chloride, praseodymium chloride, neodymium chloride, promethium chloride, yttrium chloride, or scandium chloride. The aqueous solution of the rare earth chloride has a mass fraction of 1% at room temperature and a pH value of 7-9. The rare earth nitrate is a single rare earth salt, such as lanthanum nitrate, cerium nitrate, praseodymium nitrate, neodymium nitrate, promethium nitrate, yttrium nitrate, or scandium nitrate. The aqueous solution of the rare earth nitrate has a mass fraction of 1% at room temperature and a pH value of 7-9. The rare earth sulfate is a single rare earth salt, such as lanthanum sulfate, cerium sulfate, praseodymium sulfate, neodymium sulfate, yttrium sulfate, or scandium sulfate. The aqueous solution of the rare earth sulfate has a mass fraction of 1% at room temperature and a pH value of 7-9. The drying is carried out in an electrically heated forced-air drying oven, with the heating rate controlled at 1-3℃ / min, and drying is carried out at 60-100℃ until the moisture content is less than 1%.

9. A titanium-based electrode plate supported on silicon-carbon nanocomposite material as described in claim 1, characterized in that: Micro-electric field positive and negative electrode plates are used for the catalytic activation of inert organic matter in the mother liquor of high-salt chemical waste water desalination crystallization.

10. The titanium-based electrode plate supported on silicon-carbon nanocomposite material according to claim 9, characterized in that: The micro-electric field is specifically designed for the catalytic activation of inert organic compounds, with a current of less than 1 mA for microcurrent applications. The input DC current density is 0.1-0.3 mA·cm^(-2), and the voltage is 1-2.5 V.

Images