A foam skeleton type composite material and its preparation method and application

Abstract

The present invention belongs to the field of wastewater treatment technology, and specifically relates to a foam skeleton type composite material, and its preparation method and application. The present invention uses an inorganic gel material to prepare a foam skeleton type composite material, which has lower cost and better mechanical properties than traditional metal-based electrode materials. While reducing costs, it improves the stability of the material; by adding a pore-forming agent, a pore structure can be generated in the matrix, which not only increases the effective contact area between the composite material and the pollutants, but also provides more exposure points for the active substance, increasing the chemical activity of the composite material; by doping active nanocarbon dots in the composite material, it has the ability to catalyze the electrochemical oxidation of halogenated hydrocarbons, which can further improve the removal efficiency of halogenated hydrocarbon pollutants in water. The composite material obtained by the present invention not only has excellent mechanical properties and durability, but also has better electrochemical properties, and has broad development prospects in the field of halogenated hydrocarbon wastewater treatment.

Description

Technical Field

[0001] The invention belongs to the technical field of wastewater treatment, and in particular relates to a foam skeleton type composite material and a preparation method and application thereof. Background Art

[0002] Chlorinated aliphatic hydrocarbons are widely used in a variety of industrial processes, including dry cleaning operations and semiconductor manufacturing. 1,2-Dichloroethane is a key industrial chemical, commonly used as an industrial solvent, metal degreaser, lead remover for gasoline and other petrochemicals, and in the production of pesticides and pharmaceuticals. Due to improper storage, use, and disposal, various chlorinated hydrocarbon contaminants enter groundwater, becoming a major persistent organic pollutant.

[0003] Currently, methods for removing chlorinated hydrocarbons from groundwater primarily include ex situ remediation and in situ remediation. Compared to ex situ remediation, in situ remediation offers advantages such as lower cost, higher efficiency, and reduced environmental impact. In situ remediation methods primarily include groundwater aeration, bioremediation, chemical redox, and electrochemical methods. Electrochemical methods offer advantages such as high efficiency, controllability, ease of operation, and broad-spectrum pollutant removal.

[0004] Traditional electrochemical applications typically use precious metals as electrode materials, resulting in high costs and relatively low chemical stability. To address this issue, researchers have been searching for alternative electrode materials to reduce costs and improve sustainability. Cement electrodes are highly favored in applications such as construction due to their low cost and high chemical stability.

[0005] However, due to the low conductivity of cement electrodes and their extremely unstable conductivity due to factors such as polarization reactions, only a few researchers have introduced them into the field of electrochemistry. Therefore, how to improve the conductivity and stability of cement electrodes has become an urgent problem in the field of electrochemistry. Summary of the Invention

[0006] The object of the present invention is to provide a foam skeleton type composite material and a preparation method and application thereof. The foam skeleton type composite material provided by the present invention has the characteristics of high electrical conductivity and high electrical conductivity stability.

[0007] In order to achieve the above object, the present invention provides the following technical solutions:

[0008] The present invention provides a foam skeleton composite material, the raw materials for preparing which include the following components in parts by weight:

[0009] 140-160 parts of inorganic gel material, 20-40 parts of conductive material dispersion, 10-20 parts of mineral fiber, 30-70 parts of water, 5-8 parts of nano carbon dot dispersion, and 10-20 parts of pore-forming agent dispersion;

[0010] The concentration of the conductive material dispersion is 0.25 to 0.4 g / mL;

[0011] The concentration of the nano carbon dot dispersion is 5 to 8 mg / mL;

[0012] The concentration of the pore-forming agent dispersion is 10-15 wt %.

[0013] Preferably, the inorganic gel material comprises silicate cement.

[0014] Preferably, the conductive material in the conductive material dispersion comprises metal fibers;

[0015] The length of the metal fiber is 3 to 5 mm, and the diameter is 8 to 13 μm.

[0016] Preferably, the mineral fibers include basalt fibers; the basalt fibers have a length of 3 to 5 mm and a diameter of 8 to 13 μm.

[0017] Preferably, the preparation of the nano carbon dot dispersion comprises:

[0018] Two pieces of biochar were placed in a liquid electrolyte for electrochemical stripping;

[0019] The liquid electrolyte includes water;

[0020] The ratio of each piece of biochar to liquid electrolyte is 50g:700-1500mL;

[0021] The conditions for electrochemical stripping include: the distance between two pieces of biochar is 3 to 8 cm; the voltage is 4 to 8 V, and the current density is 0.8 to 1.2 mA / cm 2 , the time is 4 to 6 days.

[0022] Preferably, the preparation of the conductive material dispersion includes:

[0023] first mixing the conductive material and water to obtain a first dispersion;

[0024] The first dispersion liquid and the dispersant are mixed for a second time to obtain the conductive material dispersion liquid.

[0025] Preferably, the dispersant comprises polyvinyl pyrrolidone, and the mass of the dispersant is 10-20% of the conductive material;

[0026] The first mixing is carried out under stirring conditions, the stirring speed is 400-600 rpm, and the time is 10-20 minutes;

[0027] The second mixing is performed under ultrasonic conditions, and the ultrasonic time is 10 to 20 minutes.

[0028] Preferably, the preparation method of the pore-forming agent dispersion comprises:

[0029] The biomass and the alkali solution are mixed to carry out a liquid phase reaction to obtain a reaction liquid;

[0030] Centrifuging the reaction solution to obtain an upper layer of liquid, which is the pore-forming agent dispersion;

[0031] The concentration of the alkali solution is 0.5 to 1 mol / L;

[0032] The mass ratio of the biomass to the alkali solution is 5:8;

[0033] The temperature of the liquid phase reaction is 50-80°C and the time is 40-60 minutes;

[0034] The centrifugal speed is 4000-5000 rpm and the time is 10 minutes.

[0035] The present invention also provides a method for preparing the foam skeleton composite material described in the above technical solution, comprising the following steps:

[0036] Mixing an inorganic gel material, mineral fibers, a conductive material dispersion, water, a nanocarbon dot dispersion, and a pore-forming agent dispersion to obtain a mortar;

[0037] After the mortar is solidified and formed, first curing, demoulding and second curing are performed in sequence to obtain the foam skeleton type composite material.

[0038] The present invention also provides the use of the foam skeleton type composite material described in the above technical solution or the foam skeleton type composite material prepared by the preparation method described in the above technical solution in sewage treatment.

[0039] The present invention provides a foam skeleton type composite material, the preparation raw materials of which include the following components in parts by weight: 140-160 parts of inorganic gel material, 20-40 parts of conductive material dispersion, 10-20 parts of mineral fiber, 30-70 parts of water, 5-8 parts of nano carbon dot dispersion, and 10-20 parts of pore-forming agent dispersion; the concentration of the conductive material dispersion is 0.25-0.4 g / mL; the concentration of the nano carbon dot dispersion is 5-8 mg / mL; and the concentration of the pore-forming agent dispersion is 10-15 wt%.

[0040] The present invention uses an inorganic gel material to prepare a foam skeleton composite material. Compared with traditional metal-based electrode materials, it has lower cost and better mechanical properties, reducing costs while improving the stability of the material. By adding a pore-forming agent, a pore structure can be generated in the matrix, which not only increases the effective contact area between the composite material and the pollutants, but also provides more exposure sites for the active substances, increasing the chemical activity of the composite material. By doping the composite material with activated nanocarbon dots, which have the ability to catalyze the electrochemical oxidation of halogenated hydrocarbons, the removal efficiency of halogenated hydrocarbon pollutants in water can be further improved. The composite material obtained by the present invention not only has excellent mechanical and durability properties, but also has better electrochemical properties, and has broad development prospects in the field of halogenated hydrocarbon wastewater treatment.

[0041] The present invention also provides a method for preparing the foam skeleton composite material described in the above technical solution, comprising the following steps: mixing an inorganic gel material, mineral fiber, a conductive material dispersion, water, a nanocarbon dot dispersion, and a pore-forming agent dispersion to obtain a mortar; curing the mortar into a shape, and then sequentially performing a first curing step, demolding, and a second curing step to obtain the foam skeleton composite material. The preparation method provided by the present invention has the advantages of simple process steps, easy operation, and high production efficiency. DETAILED DESCRIPTION

[0042] The present invention provides a foam skeleton composite material, the raw materials for preparing which include the following components in parts by weight:

[0043] 140-160 parts of inorganic gel material, 20-40 parts of conductive material dispersion, 10-20 parts of mineral fiber, 30-70 parts of water, 5-8 parts of nano carbon dot dispersion, and 10-20 parts of pore-forming agent dispersion;

[0044] The concentration of the conductive material dispersion is 0.25 to 0.4 g / mL;

[0045] The concentration of the nano carbon dot dispersion is 5 to 8 mg / mL;

[0046] The concentration of the pore-forming agent dispersion is 10-15 wt %.

[0047] In the present invention, unless otherwise specified, all components are commercially available products well known to those skilled in the art.

[0048] In parts by weight, the raw materials for preparing the foam skeleton composite material provided by the present invention include 140 to 160 parts of inorganic gel material, more preferably 145 to 155 parts, and more preferably 150 parts. In the present invention, the inorganic gel material preferably includes silicate cement.

[0049] Based on the weight of the inorganic gel material, the raw materials for preparing the foam skeleton composite material provided by the present invention include 20 to 40 parts of a conductive material dispersion, more preferably 25 to 38 parts, and even more preferably 30 to 35 parts. In the present invention, the concentration of the conductive material dispersion is 0.25 to 0.4 g / mL. In the present invention, the solvent in the conductive material dispersion is preferably water, and the mass of the water is preferably 2 / 5 to 5 / 7 of the mass of the water in the raw materials for preparing the foam skeleton composite material.

[0050] In the present invention, the conductive material in the conductive material dispersion preferably includes metal fibers, and the metal fibers further preferably include one or more of iron fibers, aluminum fibers, and copper fibers. The metal fibers are preferably 3 to 5 mm in length and 8 to 13 μm in diameter. By adding metal fibers of appropriate length, the present invention achieves good dispersibility and forms a coherent conductive network within the composite material, thereby improving the composite material's conductivity and further enhancing the composite material's mechanical properties and corrosion resistance.

[0051] In the present invention, the preparation of the conductive material dispersion preferably includes: first mixing the conductive material and water to obtain a first dispersion; and second mixing the first dispersion and a dispersant to obtain the conductive material dispersion.

[0052] In the present invention, the dispersant preferably comprises polyvinyl pyrrolidone, and the mass of the dispersant is preferably 10-20% of the conductive material, more preferably 12-15%. In the present invention, the first mixing is preferably performed under stirring conditions, the stirring speed is preferably 400-600 rpm, and the stirring time is preferably 10-20 minutes. In the present invention, the second mixing is preferably performed under ultrasonic conditions, and the ultrasonic time is preferably 10-20 minutes.

[0053] The raw materials for preparing the foam skeleton composite material provided by the present invention include 10 to 20 parts, preferably 12 to 18 parts, and even more preferably 15 to 16 parts, of mineral fiber, based on the weight of the inorganic gel material. In the present invention, the mineral fiber preferably includes basalt fiber; the basalt fiber is preferably 3 to 5 mm in length and 8 to 13 μm in diameter.

[0054] Based on the weight of the inorganic gel material, the raw materials for preparing the foam skeleton composite material provided by the present invention include 30 to 70 parts of water, more preferably 40 to 60 parts, and even more preferably 45 to 50 parts.

[0055] The raw materials for preparing the foam skeleton composite material provided by the present invention include 5 to 8 parts, preferably 6 to 7 parts, of a nanocarbon dot dispersion, based on the weight of the inorganic gel material. In the present invention, the concentration of the nanocarbon dot dispersion is 5 to 8 mg / mL. In the present invention, the solvent of the nanocarbon dot dispersion is preferably water.

[0056] In the present invention, the preparation of the nano-carbon dot dispersion preferably includes: placing two pieces of biomass carbon in a liquid electrolyte and performing electrochemical stripping.

[0057] In the present invention, the liquid electrolyte preferably includes water; the ratio of each biochar to the liquid electrolyte is preferably 50g:700-1500mL. In the present invention, the electrochemical stripping conditions preferably include: the distance between the two biochars is 3-8cm; the voltage is 4-8V, and the current density is 0.8-1.2mA / cm 2 , the time is 4 to 6 days.

[0058] After the electrochemical stripping, the present invention further preferably includes filtering and centrifuging the obtained liquid, and the upper layer obtained by centrifugation is the nano-carbon dot dispersion. In the present invention, the centrifugation speed is preferably 4000-5000 rpm, and the time is preferably 10-15 minutes.

[0059] The raw materials for preparing the foam skeleton composite material provided by the present invention include 10 to 20 parts, preferably 12 to 18 parts, and even more preferably 15 to 16 parts, of a pore-forming agent dispersion, based on the weight of the inorganic gel material. In the present invention, the concentration of the pore-forming agent dispersion is 10 to 15 wt %. In the present invention, the solvent in the pore-forming agent dispersion is preferably water.

[0060] In the present invention, the method for preparing the pore-forming agent dispersion preferably comprises: mixing biomass and alkaline solution, performing a liquid phase reaction to obtain a reaction liquid; and centrifuging the reaction liquid to obtain an upper layer liquid, which is the pore-forming agent dispersion.

[0061] In the present invention, the biomass preferably includes domestic sludge and / or soybean meal. Before the mixing, the present invention also preferably includes pre-treatment of the biomass, and the pre-treatment preferably includes crushing and dehydration. In the present invention, the alkali solution preferably includes NaOH solution; the concentration of the alkali solution is preferably 0.5-1 mol / L. In the present invention, the mass ratio of the biomass and the alkali solution is preferably 5:8. In the present invention, the temperature of the liquid phase reaction is preferably 50-80°C, and the time is preferably 40-60 min. In the present invention, the rotation speed of the centrifugation is preferably 4000-5000 rpm, and the time is preferably 10 min.

[0062] The present invention also provides a method for preparing the foam skeleton composite material described in the above technical solution, comprising the following steps:

[0063] Mixing an inorganic gel material, mineral fibers, a conductive material dispersion, water, a nanocarbon dot dispersion, and a pore-forming agent dispersion to obtain a mortar;

[0064] After the mortar is solidified and formed, first curing, demoulding and second curing are performed in sequence to obtain the foam skeleton type composite material.

[0065] The present invention has no particular limitation on the mixing process, and the raw materials can be uniformly mixed using methods well known to those skilled in the art.

[0066] In the present invention, the curing process preferably includes placing the mortar in a mold, extruding it into shape, and then vibrating and smoothing it. In the present invention, the temperature of the first curing step is preferably 22-28°C, the humidity is preferably 85-90%, and the duration is preferably 8-28 hours. In the present invention, the temperature of the second curing step is preferably 22-28°C, the humidity is preferably 85-90%, and the duration is preferably 28 days.

[0067] The present invention also provides the use of the foam skeleton type composite material described in the above technical solution or the foam skeleton type composite material prepared by the preparation method described in the above technical solution in sewage treatment.

[0068] To further illustrate the present invention, a foam skeleton composite material provided by the present invention, its preparation method and application are described in detail below in conjunction with examples, but they should not be construed as limiting the scope of protection of the present invention.

[0069] Example 1

[0070] Two 50g biochars were placed in 700mL water with a distance of 5cm between the two biochars. The voltage was 6V and the current density was 1mA / cm 2 Electrochemical stripping was performed under the conditions of , and the stripping was continued for 5 days; then the obtained uniform dark yellow solution was filtered and centrifuged at a speed of 5000 for 15 minutes, and the upper layer solution was taken as the nanocarbon dot dispersion with a concentration of 8 mg / mL;

[0071] 60 g of aluminum fiber was added to 180 mL of water and stirred at 500 rpm for 10 min. After uniform dispersion, 10 g of polyvinyl pyrrolidone was added and ultrasonic dispersion was performed for 10 min to obtain a fiber dispersion with a concentration of 0.33 g / mL.

[0072] After the sludge is crushed and dehydrated before treatment, it is mixed with a sodium hydroxide solution with a concentration of 1 mol / L at a liquid-solid ratio of 5:8, and then a liquid phase reaction is carried out at 50°C. After the reaction time of 40 minutes, the obtained liquid is centrifuged at a speed of 5000 rpm for 10 minutes in a centrifuge to remove the precipitate. The obtained supernatant is the pore-forming agent dispersion with a concentration of 10wt%;

[0073] 600 g of Portland cement, 180 mL of fiber dispersion, 100 mL of water, 25 mL of nanocarbon dispersion, and 60 mL of pore-forming agent dispersion were added to a blender and stirred uniformly to obtain mortar;

[0074] The obtained mortar was filled into a mold, extruded and formed, vibrated and smoothed, and placed in a constant temperature and humidity cement curing box. After curing for 15 hours at a temperature of 25°C and a humidity of 90%, the mold was demolded. After demolding, the mold was further cured for 28 days at a temperature of 25°C and a humidity of 90% to obtain a foam skeleton composite material.

[0075] Performance Testing

[0076] The resistivity test module was prepared by pouring the pre-cured slurry into a 40mm×40mm×20mm cement paste mold. A 25mm×30mm×1mm brass sheet was inserted on both sides as an electrode. The two brass sheets were kept parallel and 20mm apart. After demolding, the resistance of the conductive concrete was measured using the two-electrode method. An MS-603D DC regulated power supply was connected to the two electrodes and a 10V voltage was applied to measure the resistance of the sample. The resistivity ρ of the sample was calculated using Equation 1:

[0077] ρ=UA / IL(1)

[0078] U is the voltage applied to the specimen by the power supply, I is the current passing through the specimen, A is the cross-sectional area of ​​the specimen, and L is the distance between the two electrodes. Experimental results show that the foam skeleton composite material prepared under these conditions has a resistance of 0.220Ω·m.

[0079] The pre-cured slurry was then poured into two 150mm × 100mm × 3mm cement paste molds to prepare functional material modules, each with a 25mm × 30mm × 1mm brass sheet inserted into each mold. After demolding, the modules were used as electrode materials. The electrode materials were placed in an electrolytic cell and connected to the two functional material modules using an MS-603D DC regulated power supply. A 6V voltage was applied to treat wastewater containing 1,2-dichloroethane (initial concentration: 200mg / L). After 2 hours, the initial concentration of 1,2-dichloroethane after treatment was measured to be 73.90mg / L, with a removal efficiency of 63.05%.

[0080] Example 2

[0081] Two 50g biochars were placed in 700mL water with a distance of 5cm between the two biochars. The voltage was 6V and the current density was 1mA / cm 2 Electrochemical stripping was performed under the conditions of , and the stripping was continued for 5 days; then the obtained uniform dark yellow solution was filtered and centrifuged at a speed of 5000 for 15 minutes, and the upper layer solution was taken as the nanocarbon dot dispersion with a concentration of 8 mg / mL;

[0082] 50 g of aluminum fiber was added to 180 mL of water and stirred at 500 rpm for 10 min. After uniform dispersion, 10 g of polyvinyl pyrrolidone was added and ultrasonic dispersion was performed for 10 min to obtain a fiber dispersion with a concentration of 0.27 g / mL.

[0083] After crushing and dehydrating the soybean meal, it was mixed with a 1 mol / L sodium hydroxide solution at a liquid-to-solid ratio of 5:8, and then a liquid phase reaction was carried out at 50°C for 40 minutes. The resulting liquid was centrifuged at 5000 rpm for 10 minutes to remove the precipitate. The supernatant obtained was the pore-forming agent dispersion with a concentration of 10 wt%;

[0084] 600 g of Portland cement, 180 mL of fiber dispersion, 100 mL of water, 30 mL of nanocarbon dispersion, and 70 mL of pore-forming agent dispersion were added to a blender and stirred uniformly to obtain mortar;

[0085] The obtained mortar was filled into a mold, extruded and formed, vibrated and smoothed, and placed in a constant temperature and humidity cement curing box. After curing for 20 hours at a temperature of 25°C and a humidity of 90%, the mold was demolded. After demolding, the mold was further cured for 28 days at a temperature of 25°C and a humidity of 90% to obtain a foam skeleton composite material.

[0086] Performance Testing

[0087] A portion of the pre-cured slurry was poured into a 40mm × 40mm × 20mm mold to prepare a resistivity test module. 25mm × 30mm × 1mm brass sheets were inserted on both sides as electrodes, keeping the two brass sheets parallel and 20mm apart. After demolding, the resistance of the conductive concrete was measured using the two-electrode method. An MS-603D DC regulated power supply was connected to the two electrodes and a 10V voltage was applied to measure the resistance of the sample. The resistivity ρ of the sample was calculated using Equation 1:

[0088] ρ=UA / IL (1)

[0089] U is the voltage applied to the specimen by the power supply, I is the current flowing through the specimen, A is the cross-sectional area of ​​the specimen, and L is the distance between the two electrodes. Experimental results show that the electrical conductivity of the foam skeleton composite prepared under these conditions is 0.389 Ω·m.

[0090] The pre-cured slurry was then poured into two 150mm × 100mm × 3mm molds to prepare functional material modules, each with a 25mm × 30mm × 1mm brass sheet inserted into each. After demolding, the resulting modules were used as electrode materials. The electrode materials were placed in an electrolytic cell and connected to the two functional material modules using an MS-603D DC regulated power supply. A 6V voltage was applied to treat wastewater containing 1,2-dichloroethane (initial concentration: 200mg / L). After 2 hours, the initial concentration of 1,2-dichloroethane after treatment was measured to be 84.56mg / L, representing a removal efficiency of 57.72%.

[0091] Example 3

[0092] Two 50g biochars were placed in 1500mL water with a distance of 5cm between the two biochars. The voltage was 8V and the current density was 1.2mA / cm 2 Electrochemical stripping was performed under the conditions of , and the stripping was continued for 5 days; then the obtained uniform dark yellow solution was filtered and centrifuged at a speed of 5000 for 15 minutes, and the upper layer solution was taken as the nanocarbon dot dispersion with a concentration of 5 mg / mL;

[0093] 60 g of steel fiber was added to 180 mL of water and stirred at 500 rpm for 10 min. After uniform dispersion, 10 g of polyvinyl pyrrolidone was added and ultrasonic dispersion was performed for 10 min to obtain a fiber dispersion with a concentration of 0.33 g / mL.

[0094] After crushing and dehydrating the soybean meal, it was mixed with a 0.8 mol / L sodium hydroxide solution at a liquid-to-solid ratio of 5:8, and then a liquid phase reaction was carried out at 50°C for 40 minutes. The resulting liquid was centrifuged at 4000 rpm for 15 minutes to remove the precipitate. The supernatant obtained was the pore-forming agent dispersion with a concentration of 10 wt%;

[0095] 600 g of Portland cement, 180 mL of fiber dispersion, 100 mL of water, 25 mL of nanocarbon dispersion, and 60 mL of pore-forming agent dispersion were added to a blender and stirred uniformly to obtain mortar;

[0096] The obtained mortar was filled into a mold, extruded and formed, vibrated and smoothed, and placed in a constant temperature and humidity cement curing box. After curing for 8 hours at a temperature of 28°C and a humidity of 85%, the mold was demolded. After demolding, the mold was further cured for 28 days at a temperature of 28°C and a humidity of 85% to obtain a foam skeleton composite material.

[0097] Performance Testing

[0098] A portion of the pre-cured slurry was poured into a 40mm × 40mm × 20mm mold to prepare a resistivity test module. 25mm × 30mm × 1mm brass sheets were inserted on both sides as electrodes, keeping the two brass sheets parallel and 20mm apart. After demolding, the resistance of the conductive concrete was measured using the two-electrode method. An MS-603D DC regulated power supply was connected to the two electrodes and a 10V voltage was applied to measure the resistance of the sample. The resistivity ρ of the sample was calculated using Equation 1:

[0099] ρ=UA / IL (1)

[0100] U is the voltage applied to the specimen by the power supply, I is the current passing through the specimen, A is the cross-sectional area of ​​the specimen, and L is the distance between the two electrodes. Experimental results show that the foam skeleton composite material prepared under these conditions has a resistance of 0.220Ω·m.

[0101] The pre-cured slurry was then poured into two 150mm × 100mm × 3mm cement paste molds to prepare functional material modules, each with a 25mm × 30mm × 1mm brass sheet inserted into each mold. After the sample completed the curing process and was demolded, it was used as an electrode material. The electrode material was placed in an electrolytic cell and connected to the two functional material modules using an MS-603D DC regulated power supply. A 6V voltage was applied to treat wastewater containing 1,2-dichloroethane (initial concentration: 200mg / L). After 2 hours, the initial concentration of 1,2-dichloroethane after treatment was measured to be 77.54mg / L, with a removal efficiency of 61.23%.

[0102] Although the above embodiment provides a detailed description of the present invention, it is only a part of the embodiments of the present invention, not all of the embodiments. Other embodiments can be obtained based on this embodiment without creativity, and these embodiments all fall within the scope of protection of the present invention.

Claims

1. A foam skeleton type composite electrode material, characterized in that: The preparation raw materials include the following components in parts by weight: 140-160 parts of inorganic gel material, 20-40 parts of conductive material dispersion, 10-20 parts of mineral fiber, 30-70 parts of water, 5-8 parts of nano carbon dot dispersion and 10-20 parts of pore-forming agent dispersion; The inorganic gel material includes silicate cement; The concentration of the conductive material dispersion is 0.25-0.4 g / mL; the conductive material in the conductive material dispersion includes metal fibers; The concentration of the nano carbon dot dispersion is 5-8 mg / mL; The preparation method of the pore-forming agent dispersion comprises: mixing biomass and alkaline solution, performing liquid phase reaction to obtain a reaction liquid; centrifuging the reaction liquid to obtain an upper layer liquid which is the pore-forming agent dispersion; The concentration of the pore-forming agent dispersion is 10-15 wt %; The foam skeleton type composite electrode material is used for electrochemical catalytic oxidation of halogenated hydrocarbons; The method for preparing the foam skeleton type composite electrode material comprises the following steps: Mixing an inorganic gel material, mineral fibers, a conductive material dispersion, water, a nanocarbon dot dispersion, and a pore-forming agent dispersion to obtain a mortar; After the mortar is solidified and formed, first curing, demoulding and second curing are performed in sequence to obtain the foam skeleton type composite electrode material.

2. The foam skeleton type composite electrode material according to claim 1, characterized in that: The metal fiber has a length of 3-5 mm and a diameter of 8-13 μm.

3. The foam skeleton type composite electrode material according to claim 1, characterized in that: The mineral fibers include basalt fibers; the basalt fibers have a length of 3 to 5 mm and a diameter of 8 to 13 μm.

4. The foam skeleton type composite electrode material according to claim 1, characterized in that: The preparation of the nano carbon dot dispersion comprises: Two pieces of biochar were placed in a liquid electrolyte for electrochemical stripping; The liquid electrolyte includes water; The ratio of each piece of biochar to liquid electrolyte is 50g:700~1500mL; The conditions for electrochemical stripping include: the distance between two pieces of biochar is 3-8 cm; the voltage is 4-8 V, and the current density is 0.8-1.2 mA / cm 2 , the time is 4 to 6 days.

5. The foam skeleton type composite electrode material according to claim 1, characterized in that: The preparation of the conductive material dispersion comprises: first mixing the conductive material and water to obtain a first dispersion; The first dispersion liquid and the dispersant are mixed for a second time to obtain the conductive material dispersion liquid.

6. The foam skeleton type composite electrode material according to claim 5, characterized in that: The dispersant includes polyvinyl pyrrolidone, and the mass of the dispersant is 10-20% of the conductive material; The first mixing is performed under stirring conditions, the stirring speed is 400-600 rpm, and the time is 10-20 min; The second mixing is performed under ultrasonic conditions, and the ultrasonic time is 10 to 20 minutes.

7. The foam skeleton type composite electrode material according to claim 1, characterized in that: The concentration of the alkali solution is 0.5~1mol / L; The mass ratio of the biomass to the alkali solution is 5:8; The liquid phase reaction temperature is 50-80°C and the reaction time is 40-60 minutes; The centrifugal speed is 4000-5000 rpm and the time is 10 min.

8. The method for preparing the foam skeleton type composite electrode material according to any one of claims 1 to 7, characterized in that: The following steps are involved: Mixing an inorganic gel material, mineral fibers, a conductive material dispersion, water, a nanocarbon dot dispersion, and a pore-forming agent dispersion to obtain a mortar; After the mortar is solidified and formed, first curing, demoulding and second curing are performed in sequence to obtain the foam skeleton type composite electrode material.

9. Use of the foam skeleton type composite electrode material according to any one of claims 1 to 7 or the foam skeleton type composite electrode material prepared by the preparation method according to claim 8 in sewage treatment.