Filtering adsorptive activated carbon composite material, and preparation method and application thereof

Abstract

This invention relates to the field of activated carbon technology, specifically to a filter adsorption activated carbon composite material, its preparation method, and its application. A method for preparing a filter adsorption activated carbon composite material includes: preparation and pretreatment of high specific surface area activated carbon, antibacterial modification of the activated carbon, and preparation of the activated carbon composite material. This invention employs a combination of low-temperature activation with phosphoric acid and high-temperature CO2 secondary activation to construct a multi-level interconnected porous carbon material, introducing oxygen-containing functional groups and defect sites to provide sufficient loading space for functionalization. Hydrothermal-pyrolysis anchoring of Bi and Zn co-doped nickel-based nanoparticles achieves multi-component synergistic antibacterial action. Furthermore, the introduction of modified hydrotalcite enhances VOCs adsorption and selective chemisorption, improves hydrophobic stability, and slows the release of antibacterial components. The material integrates physical adsorption, chemical adsorption, and contact antibacterial properties, possessing both high adsorption capacity and long-lasting antibacterial performance.

Description

[0001] This invention relates to the field of activated carbon technology, specifically to a filter adsorption activated carbon composite material, its preparation method, and its application. Background Technology

[0002] Activated carbon, with its well-developed pore structure, large specific surface area, and good physicochemical stability, has long been widely used in air purification, water treatment, solvent recovery, and personal protective equipment. Its adsorption mechanism mainly relies on physical adsorption, using van der Waals forces to capture pollutant molecules within micropores and mesopores. However, with the acceleration of modern industrialization and urbanization, indoor and outdoor air quality is becoming increasingly complex, with pollutants showing a trend towards diversification and lower concentrations. This includes not only volatile organic compounds such as formaldehyde and benzene series compounds, but also a large number of microbial pollutants such as bacteria and fungi. Faced with this complex pollution scenario, traditional activated carbon materials are gradually revealing the following technical bottlenecks: Firstly, regarding pore structure construction, existing activation technologies struggle to achieve synergistic control of high specific surface area and multi-level interconnected pores. While commonly used physical activation methods (such as steam and CO2 activation) can generate some porosity, the pore structure is often singular, dominated by micropores, which hinders rapid diffusion of gas molecules and adsorption of large molecules. Chemical activation methods (such as phosphoric acid and potassium hydroxide activation) can introduce mesopores, but they suffer from problems such as easy pore blockage, high activation temperatures, and severe equipment corrosion. A single activation method cannot simultaneously achieve the high specific capacity advantage of micropores and the rapid mass transfer channel function of mesopores, limiting the material's comprehensive capture capacity for complex pollutants.

[0003] Secondly, regarding the imparting of antibacterial function, existing technologies generally suffer from problems such as uneven distribution of antibacterial components, easy aggregation and pore blockage, and burst release of metal ions. To inhibit the growth of microorganisms on the surface of filter media, researchers have attempted to load antibacterial metals such as silver, copper, and zinc, or their oxides, onto activated carbon through methods such as impregnation and deposition. However, existing methods often fail to achieve uniform anchoring of nanoparticles on the inner wall of activated carbon pores, and particles easily aggregate on the surface. This not only leads to insufficient exposure of antibacterial active sites but also severely blocks micropores, sacrificing the original high specific surface area and adsorption capacity of activated carbon. From the perspective of antibacterial mechanism, single metal components (such as silver ions) have a narrow antibacterial spectrum, and long-term use carries the risk of inducing drug resistance in microorganisms; while the burst release problem of ionic antibacterial agents in practical applications shortens the service life of materials and may bring potential biosafety risks.

[0004] Finally, regarding selective adsorption, traditional activated carbon mainly relies on physical adsorption, exhibiting weak capture ability for polar harmful gases (such as formaldehyde, ammonia, and sulfur dioxide), especially with low adsorption efficiency under low concentration conditions. Furthermore, in high humidity environments, water molecules compete with pollutant molecules for adsorption within the micropores, and capillary condensation of water vapor significantly occupies adsorption sites, leading to a substantial decrease in the material's adsorption performance for the target pollutants. This sensitivity to humidity severely limits the practical application of activated carbon materials in complex environmental conditions.

[0005] Therefore, the development of a multifunctional filter adsorption activated carbon composite material with high adsorption capacity, broad-spectrum antibacterial properties, selective chemical adsorption capacity and long-term stability, as well as its preparation method and application, has become an urgent need in the field of air purification. Summary of the Invention

[0006] To address the shortcomings of existing technologies, the present invention aims to provide a filter adsorption activated carbon composite material, its preparation method, and its application.

[0007] This invention provides a method for preparing a filter adsorption activated carbon composite material, comprising: S1: Preparation and pretreatment of high specific surface area activated carbon; After grinding and pulverizing the biomass-based material through an 80-100 mesh sieve, it is mixed with 85wt% wet phosphoric acid in a certain proportion, impregnated and dried, activated in a high-temperature tube furnace under nitrogen atmosphere and then activated again under carbon dioxide atmosphere, and washed and dried to obtain high specific surface area activated carbon. S2: Antibacterial modification of activated carbon; A mixture of nickel chloride hexahydrate ethanol solution, sodium acetate solution, and trisodium citrate solution was added, along with high specific surface area activated carbon, bismuth nitrate pentahydrate, and zinc nitrate hexahydrate. The mixture was then subjected to hydrothermal reaction, washing, drying, and nitrogen atmosphere treatment to obtain antibacterial modified activated carbon. S3: Preparation of activated carbon composite materials; Vinyl hydrotalcite was obtained by reacting it with vinyltriethoxysilane in toluene solution. Then, it was reacted with 1-vinyl-3-butylimidazolium bromide, styrene, and AIBN under an argon atmosphere. After washing and drying, it was reacted with 1,2-dichloroethane, dimethoxymethane, and anhydrous ferric chloride. After centrifugation, washing, Soxhlet extraction, and drying, modified hydrotalcite was obtained. Antibacterial modified activated carbon and modified hydrotalcite were mixed in a mass ratio of 3-5:1 to prepare an activated carbon composite material.

[0008] As a preferred aspect, S1: the preparation and pretreatment of high specific surface area activated carbon specifically includes the following steps: S1.1: Grind and pulverize the biomass-based material, then pass it through an 80-100 mesh sieve. Add 40-50 parts by weight of 85wt% wet-process phosphoric acid to 20-30 parts by weight of the biomass-based powder, stir evenly, then impregnate and dry in an oven at 95-100℃ for 2-3 hours. After cooling to room temperature, place it in a high-temperature tube furnace and heat it to 550-600℃ under a nitrogen atmosphere for 1-2 hours. After cooling to room temperature, wash it with deionized water until neutral, and then dry it at 100-120℃ for 10-12 hours to obtain activated biochar. S1.2: Place the activated biochar in a high-temperature tube furnace and heat it to 750-800℃ under a carbon dioxide atmosphere for 1-2 hours. Then cool it to room temperature, wash it with deionized water and dry it to obtain activated carbon with high specific surface area.

[0009] As a preferred aspect, the biomass-based material in step S1.1 is one of the following: wood chips, coconut shells, walnut shells, rice husks, straw, and peanut shells.

[0010] As a preferred aspect, in step S1.1, the heating rate of the high-temperature tubular furnace is 5-6℃ / min, and the nitrogen flow rate is 80-90mL / min.

[0011] As a preferred aspect, in step S1.2, the heating rate of the high-temperature tubular furnace is 5-6℃ / min, and the carbon dioxide flow rate is 100-120mL / min.

[0012] As a preferred aspect, S2: the antibacterial modification of activated carbon specifically includes the following steps: S2.1: Add 0.2-0.3 parts by weight of nickel chloride hexahydrate to 25-30 parts by weight of ethanol, and stir at 200-300 rpm for 20-30 min to obtain a nickel chloride hexahydrate ethanol solution. Add 1.4-1.6 parts by weight of sodium acetate to 10-12 parts by weight of deionized water, and stir at 200-300 rpm for 20-30 min to obtain a sodium acetate solution. Add 0.5-0.8 parts by weight of trisodium citrate to 15-20 parts by weight of distilled water, and stir at 200-300 rpm for 20-30 min to obtain a trisodium citrate solution. S2.2: At 30-35℃, mix and stir the nickel chloride hexahydrate ethanol solution, sodium acetate solution, and trisodium citrate solution for 20-30 min. Then add 12-15 parts by weight of high specific surface area activated carbon, 0.3-0.5 parts by weight of bismuth nitrate pentahydrate, and 0.2-0.3 parts by weight of zinc nitrate hexahydrate. After stirring and mixing, transfer to a hydrothermal reactor, seal, and maintain at 140-145℃ for 18-20 h. Cool to room temperature, then wash the product with deionized water and ethanol 3-5 times in sequence. Then dry at 60-70℃ for 4-6 h. Finally, treat at 500-520℃ under nitrogen atmosphere for 2-3 h to obtain antibacterial modified activated carbon.

[0013] As a preferred aspect, S3: The preparation of the activated carbon composite material specifically includes the following steps: S3.1: Add 2-3 parts by weight of aluminum hydrotalcite and 10-12 parts by weight of vinyltriethoxysilane to 70-80 parts by weight of toluene solution, then reflux at 80-90℃ for 20-24h, then wash with ethanol and deionized water 3-5 times in sequence, and dry under vacuum to obtain vinylated hydrotalcite. S3.2: Add 1-2 parts by weight of 1-vinyl-3-butylimidazolium bromide to 100-120 parts by weight of N,N-dimethylformamide, stir to dissolve, add 2-3 parts by weight of styrene, continue stirring and mixing for 10-20 min, then add 1-2 parts by weight of vinylized hydrotalcite, sonicate and mix for 5-10 min, then add 0.01-0.03 parts by weight of AIBN, react at 65-70℃ for 28-30 h under argon atmosphere, then wash with ultrapure water and methanol 3-5 times in sequence, and dry under vacuum at 60-80℃ to obtain hydrotalcite-polymer composite material; S3.3: Add 200-230 parts by weight of 1,2-dichloroethane and 25-30 parts by weight of dimethoxymethane to 1-2 parts by weight of the hydrotalcite-polymer composite material, and ultrasonically stir for 5-8 min. Then stir at room temperature for 300-500 rpm for 30-40 min. Then add 5-8 parts by weight of anhydrous ferric chloride, and heat to 80-90℃ for 20-24 h. After the reaction is complete, add excess methanol and stir at 1000-1200 rpm for 10-20 min. Then wash the reactants with methanol and deionized water 3-5 times in sequence. Finally, extract with methanol using a Soxhlet extractor for 12-14 h and vacuum dry at 60-70℃ to obtain modified hydrotalcite. S3.4: Antibacterial modified activated carbon and modified hydrotalcite are mixed at a mass ratio of 3-5:1 at 300-500 rpm for 1-2 hours to prepare activated carbon composite material.

[0014] The present invention also provides a filter adsorption activated carbon composite material, which is prepared by any of the methods described in the present invention for preparing a filter adsorption activated carbon composite material.

[0015] This invention also provides an application of a filter adsorption activated carbon composite material in air filtration, the application including air purification and filtration in the fields of electronics, photovoltaics, medical and health care, biopharmaceuticals, food, rail transportation, communication equipment, and shopping malls.

[0016] The present invention has the following advantages: 1. This invention employs a combination of low-temperature phosphoric acid activation and high-temperature CO2 secondary activation to synergistically construct a multi-level interconnected pore structure with high specific surface area and large pore volume. Phosphoric acid activation initially forms a rich microporous and mesoporous framework, while CO2 activation further etches and expands the pores, clearing blockages and providing ample loading space for subsequent functionalization modifications. Simultaneously, the two-step activation process introduces abundant oxygen-containing functional groups and surface defect sites onto the carbon material surface, significantly enhancing the affinity for metal precursors and promoting the uniform anchoring and firm binding of subsequent antibacterial components. Thanks to the low degree of pore blockage caused by uniformly dispersed nanoparticles, the activated carbon core retains excellent pollutant adsorption capacity, enabling the composite material to possess both high adsorption capacity and long-lasting antibacterial properties.

[0017] 2. This invention successfully anchors Bi and Zn co-doped nickel-based composite nanoparticles on the surface and within the pores of activated carbon using a hydrothermal-pyrolysis process. This composite system uses nickel as the core antibacterial component, and the slow release of Ni... 2+ Zn disrupts microbial cell structure and interferes with their metabolism; 2+ Bi achieves sterilization by disrupting the integrity of microbial cell membranes and interfering with enzyme activity and metabolic processes. 3+ It can inhibit bacterial replication and respiratory metabolism by binding to bacterial proteins and nucleic acids; the two ions have different targets and complementary mechanisms, allowing them to attack microorganisms simultaneously through multiple pathways, significantly improving the antibacterial rate and efficacy, and avoiding the problem of tolerance easily developed with single ions; the introduced Bi 3+ With Zn 2+ Not only does it possess antibacterial activity, but it can also react with Ni 2+ It forms a multi-component synergistic antibacterial effect, effectively broadens the antibacterial spectrum, improves the antibacterial rate, and solves the problem of insufficient antibacterial efficiency of single components.

[0018] 3. This invention introduces modified hydrotalcite into activated carbon composite materials. Through surface-initiated polymerization, a polymer layer containing polystyrene segments and ionic liquid units is grafted onto the surface of the hydrotalcite. Subsequently, through a hypercrosslinking reaction, using dimethoxymethane as an external crosslinking agent and catalyzed by anhydrous ferric chloride, the polystyrene segments on the hydrotalcite surface are further crosslinked to form a rigid microporous network. This network introduces a large number of secondary and ultramicropores, significantly enhancing the physical capture capacity of volatile organic compounds in the air, particularly improving the adsorption efficiency of low-concentration pollutants. Simultaneously, the grafted 1-vinyl-3-butylimidazolium bromide ionic liquid units can achieve selective chemical adsorption of polar harmful gases through dipole interactions and ion exchange mechanisms, overcoming the limitations of traditional physical adsorption. Furthermore, the hydrophobic network formed by the polystyrene crosslinking effectively inhibits capillary condensation of water vapor within the micropores, reducing competition for adsorption sites by water molecules under high humidity conditions and ensuring stable adsorption performance of the material under complex humidity conditions. This rigid polymer network also acts as a protective barrier, effectively slowing down the rapid release of the internal Bi, Zn, and Ni multi-metal-based antibacterial components, thus achieving long-lasting antibacterial activity. Through this multi-synergistic mechanism of "physical adsorption-chemical adsorption-contact inhibition," the composite material can efficiently capture air pollutants and microorganisms while killing them in situ, significantly inhibiting the growth of microorganisms in the filter layer, thereby extending the filter life and ensuring the biosafety of the air outlet quality. Attached Figure Description

[0019] Figure 1 This is a schematic diagram of the preparation method of the filter adsorption activated carbon composite material used in the embodiments of the present invention. Detailed Implementation

[0020] To enable those skilled in the art to better understand the technical solutions of this invention, the technical solutions of this invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of this invention.

[0021] Example 1: A method for preparing a filter adsorption activated carbon composite material, referring to... Figure 1 ,include: S1: Preparation and pretreatment of high specific surface area activated carbon S1.1: The straw is ground and crushed, then passed through an 80-mesh sieve. 40 parts by weight of 85wt% wet phosphoric acid are added to 20 parts by weight of straw powder and stirred evenly. The mixture is then impregnated and dried in a 95℃ oven for 2 hours. After cooling to room temperature, it is placed in a high-temperature tube furnace and heated to 550℃ at a nitrogen flow rate of 80mL / min and kept at that temperature for 1 hour. After cooling to room temperature, it is washed with deionized water until neutral and then dried at 100℃ for 10 hours to obtain activated biochar. S1.2: The activated biochar was placed in a high-temperature tube furnace and then heated to 750°C at a flow rate of 5°C / min and a carbon dioxide flow rate of 100 mL / min. The temperature was maintained for 1 hour. After cooling to room temperature, the activated biochar was washed with deionized water and dried to obtain activated carbon with high specific surface area. S2: Antibacterial modification of activated carbon S2.1: Add 0.2 parts by weight of nickel chloride hexahydrate to 25 parts by weight of ethanol and stir at 200 rpm for 20 min to obtain a nickel chloride hexahydrate ethanol solution. Add 1.4 parts by weight of sodium acetate to 10 parts by weight of deionized water and stir at 200 rpm for 20 min to obtain a sodium acetate solution. Add 0.5 parts by weight of trisodium citrate to 15 parts by weight of distilled water and stir at 200 rpm for 20 min to obtain a trisodium citrate solution. S2.2: At 30℃, nickel chloride hexahydrate ethanol solution, sodium acetate solution and trisodium citrate solution were mixed and stirred for 20 min. Then, 12 parts by weight of high specific surface area activated carbon, 0.3 parts by weight of bismuth nitrate pentahydrate and 0.2 parts by weight of zinc nitrate hexahydrate were added. After stirring and mixing, the mixture was transferred to a hydrothermal reactor, sealed and kept at 140℃ for 18 h. After cooling to room temperature, the product was washed three times with deionized water and ethanol, then dried at 60℃ for 4 h. Finally, it was treated at 500℃ for 2 h under nitrogen atmosphere to obtain antibacterial modified activated carbon. S3: Preparation of activated carbon composite materials S3.1: Add 2 parts by weight of aluminum hydrotalcite and 10 parts by weight of vinyltriethoxysilane to 70 parts by weight of toluene solution, then reflux at 80°C for 20 h, then wash three times with ethanol and deionized water respectively, and dry under vacuum to obtain vinylated hydrotalcite. S3.2: 1 part by weight of 1-vinyl-3-butylimidazolium bromide was added to 100 parts by weight of N,N-dimethylformamide and stirred until dissolved. Then, 2 parts by weight of styrene were added and stirred for 10 min. Then, 1 part by weight of vinylized hydrotalcite was added and ultrasonically mixed for 5 min. Then, 0.01 parts by weight of AIBN was added. The mixture was reacted at 65°C for 28 h under an argon atmosphere. The mixture was then washed three times with ultrapure water and methanol, and dried under vacuum at 60°C to obtain the hydrotalcite-polymer composite material. S3.3: 200 parts by weight of 1,2-dichloroethane and 25 parts by weight of dimethoxymethane were added to 1 part by weight of hydrotalcite-polymer composite material. The mixture was ultrasonically stirred for 5 min, then stirred at 300 rpm at room temperature for 30 min. Then 5 parts by weight of anhydrous ferric chloride were added, and the mixture was heated to 80℃ and reacted for 20 h. After the reaction was completed, excess methanol was added, and the mixture was stirred at 1000 rpm for 10 min. The reactants were then washed three times with methanol and deionized water, and finally extracted with methanol using a Soxhlet extracter for 12 h and dried under vacuum at 60℃ to obtain modified hydrotalcite. S3.4: Antibacterial modified activated carbon and modified hydrotalcite were mixed at a mass ratio of 3:1 at 300 rpm for 1-2 hours to prepare activated carbon composite material.

[0022] Example 2, a method for preparing a filter adsorption activated carbon composite material, see [link to example]. Figure 1 ,include: S1: Preparation and pretreatment of high specific surface area activated carbon S1.1: Grind and crush the coconut shells, then pass them through a 100-mesh sieve. Add 50 parts by weight of 85wt% wet phosphoric acid to 30 parts by weight of coconut shell powder, stir evenly, then impregnate and dry in an oven at 100℃ for 3 hours. After cooling to room temperature, place it in a high-temperature tube furnace and heat it to 600℃ at 6℃ / min and nitrogen flow rate of 90mL / min for 2 hours. After cooling to room temperature, wash with deionized water until neutral, and then dry at 120℃ for 12 hours to obtain activated biochar. S1.2: The activated biochar was placed in a high-temperature tube furnace and then heated to 800℃ at a flow rate of 6℃ / min and a carbon dioxide flow rate of 120mL / min. The temperature was maintained for 2 hours. After cooling to room temperature, the activated biochar was washed with deionized water and dried to obtain activated carbon with high specific surface area. S2: Antibacterial modification of activated carbon S2.1: Add 0.3 parts by weight of nickel chloride hexahydrate to 30 parts by weight of ethanol and stir at 300 rpm for 30 min to obtain a nickel chloride hexahydrate ethanol solution. Add 1.6 parts by weight of sodium acetate to 12 parts by weight of deionized water and stir at 300 rpm for 30 min to obtain a sodium acetate solution. Add 0.8 parts by weight of trisodium citrate to 20 parts by weight of distilled water and stir at 300 rpm for 30 min to obtain a trisodium citrate solution. S2.2: At 35℃, nickel chloride hexahydrate ethanol solution, sodium acetate solution and trisodium citrate solution were mixed and stirred for 30 min. Then, 15 parts by weight of high specific surface area activated carbon, 0.5 parts by weight of bismuth nitrate pentahydrate and 0.3 parts by weight of zinc nitrate hexahydrate were added. After stirring and mixing, the mixture was transferred to a hydrothermal reactor, sealed and kept at 145℃ for 20 h. After cooling to room temperature, the product was washed 5 times with deionized water and ethanol in sequence. Then, it was dried at 70℃ for 6 h. Finally, it was treated at 520℃ for 3 h under nitrogen atmosphere to obtain antibacterial modified activated carbon. S3: Preparation of activated carbon composite materials S3.1: Add 3 parts by weight of aluminum hydrotalcite and 12 parts by weight of vinyltriethoxysilane to 80 parts by weight of toluene solution, then reflux at 90°C for 24 h, then wash with ethanol and deionized water 5 times in sequence, and dry under vacuum to obtain vinylated hydrotalcite. S3.2: Add 2 parts by weight of 1-vinyl-3-butylimidazolium bromide to 120 parts by weight of N,N-dimethylformamide, stir to dissolve, add 3 parts by weight of styrene, continue stirring and mixing for 20 min, then add 2 parts by weight of vinylized hydrotalcite, sonicate and mix for 10 min, then add 0.03 parts by weight of AIBN, react at 70°C for 30 h under argon atmosphere, then wash with ultrapure water and methanol 5 times in sequence, and dry under vacuum at 80°C to obtain hydrotalcite-polymer composite material; S3.3: 230 parts by weight of 1,2-dichloroethane and 30 parts by weight of dimethoxymethane were added to 2 parts by weight of the hydrotalcite-polymer composite material. The mixture was ultrasonically stirred for 8 min, then stirred at 500 rpm at room temperature for 40 min. Then, 8 parts by weight of anhydrous ferric chloride were added, and the mixture was heated to 90℃ and reacted for 24 h. After the reaction was completed, excess methanol was added, and the mixture was stirred at 1200 rpm for 20 min. The reactants were then washed 5 times with methanol and deionized water, respectively. Finally, the mixture was extracted with methanol using a Soxhlet extracter for 14 h and dried under vacuum at 70℃ to obtain modified hydrotalcite. S3.4: Antibacterial modified activated carbon and modified hydrotalcite were mixed at a mass ratio of 5:1 at 500 rpm for 1-2 hours to prepare activated carbon composite material.

[0023] Example 3, a method for preparing a filter adsorption activated carbon composite material, see [link to example]. Figure 1 ,include: S1: Preparation and pretreatment of high specific surface area activated carbon S1.1: Peanut shells are ground and pulverized, then passed through a 90-mesh sieve. 45 parts by weight of 85wt% wet-process phosphoric acid are added to 25 parts by weight of peanut shell powder and stirred evenly. The mixture is then soaked and dried in an oven at 97.5℃ for 2.5h. After cooling to room temperature, it is placed in a high-temperature tube furnace and heated to 575℃ at a nitrogen flow rate of 85mL / min and held for 1.5h. After cooling to room temperature, it is washed with deionized water until neutral and then dried at 110℃ for 11h to obtain activated biochar. S1.2: The activated biochar was placed in a high-temperature tube furnace and then heated to 775℃ at a flow rate of 5.5℃ / min and a carbon dioxide flow rate of 110mL / min. The temperature was maintained for 1.5h, and then cooled to room temperature. After washing with deionized water, the activated carbon with high specific surface area was obtained. S2: Antibacterial modification of activated carbon S2.1: Add 0.25 parts by weight of nickel chloride hexahydrate to 27.5 parts by weight of ethanol and stir at 250 rpm for 25 min to obtain a nickel chloride hexahydrate ethanol solution. Add 1.5 parts by weight of sodium acetate to 11 parts by weight of deionized water and stir at 250 rpm for 25 min to obtain a sodium acetate solution. Add 0.65 parts by weight of trisodium citrate to 17.5 parts by weight of distilled water and stir at 250 rpm for 25 min to obtain a trisodium citrate solution. S2.2: At 32.5℃, nickel chloride hexahydrate ethanol solution, sodium acetate solution and trisodium citrate solution were mixed and stirred for 25 min. Then, 13.5 parts by weight of high specific surface area activated carbon, 0.4 parts by weight of bismuth nitrate pentahydrate and 0.25 parts by weight of zinc nitrate hexahydrate were added. After stirring and mixing, the mixture was transferred to a hydrothermal reactor, sealed and kept at 142.5℃ for 19 h. After cooling to room temperature, the product was washed 4 times with deionized water and ethanol, then dried at 65℃ for 5 h. Finally, it was treated at 510℃ for 2.5 h under nitrogen atmosphere to obtain antibacterial modified activated carbon. S3: Preparation of activated carbon composite materials S3.1: 2.5 parts by weight of aluminum hydrotalcite and 11 parts by weight of vinyltriethoxysilane were added to 75 parts by weight of toluene solution, and then refluxed at 85°C for 22 h. After that, the mixture was washed 4 times with ethanol and deionized water, and dried under vacuum to obtain vinylated hydrotalcite. S3.2: 1.5 parts by weight of 1-vinyl-3-butylimidazolium bromide was added to 110 parts by weight of N,N-dimethylformamide and stirred until dissolved. Then, 2.5 parts by weight of styrene was added and stirred for 15 min. Then, 1.5 parts by weight of vinylized hydrotalcite was added and ultrasonically mixed for 7.5 min. Then, 0.02 parts by weight of AIBN was added. The mixture was reacted at 67.5℃ for 29 h under an argon atmosphere. The mixture was then washed 3-5 times with ultrapure water and methanol, and dried under vacuum at 60-80℃ to obtain the hydrotalcite-polymer composite material. S3.3: 215 parts by weight of 1,2-dichloroethane and 27.5 parts by weight of dimethoxymethane were added to 1.5 parts by weight of the hydrotalcite-polymer composite material. The mixture was ultrasonically stirred for 6.5 min, then stirred at 400 rpm at room temperature for 35 min. Then 6.5 parts by weight of anhydrous ferric chloride were added, and the mixture was heated to 85℃ and reacted for 22 h. After the reaction was completed, excess methanol was added, and the mixture was stirred at 1100 rpm for 15 min. The reactants were then washed four times with methanol and deionized water, and finally extracted with methanol using a Soxhlet extracter for 13 h and dried under vacuum at 65℃ to obtain modified hydrotalcite. S3.4: Antibacterial modified activated carbon and modified hydrotalcite were mixed at a mass ratio of 4:1 at 400 rpm for 1.5 h to prepare activated carbon composite material.

[0024] Comparative Example 1 differs from Example 1 in that step S1.2 is removed, and the high specific surface area activated carbon in step S2.2 is replaced with an equal amount of activated biomass carbon prepared in S1.1. The remaining steps are unchanged to prepare the activated carbon composite material, which is referred to as Comparative Example 1.

[0025] Comparative Example 2 differs from Example 1 in that step S1.1 is removed, and the activated biochar in step S1.2 is replaced with an equal amount of straw powder, while the remaining steps remain unchanged to prepare the activated carbon composite material. This is referred to as Comparative Example 2.

[0026] Comparative Example 3 differs from Example 1 in that zinc nitrate hexahydrate in step S2.2 is replaced with an equal amount of bismuth nitrate pentahydrate, while the remaining steps remain unchanged in the preparation of the activated carbon composite material. This is referred to as Comparative Example 3.

[0027] Comparative Example 4 differs from Example 1 in that bismuth nitrate pentahydrate in step S2.2 is replaced with an equal amount of zinc nitrate hexahydrate, while the remaining steps remain unchanged in the preparation of the activated carbon composite material. This is referred to as Comparative Example 4.

[0028] Comparative Example 5 differs from Example 1 in that it removes bismuth nitrate pentahydrate and zinc nitrate hexahydrate from step S2.2, while the remaining steps remain unchanged to prepare the activated carbon composite material. This is referred to as Comparative Example 5.

[0029] Comparative Example 6 differs from Example 1 in that step S3 is removed in Comparative Example 6, while the remaining steps remain unchanged to prepare antibacterial modified activated carbon, which is an activated carbon composite material, and is referred to as Comparative Example 6.

[0030] Comparative Example 7 differs from Example 1 in that step S3.3 is removed in Comparative Example 7, while the remaining steps remain unchanged to prepare the activated carbon-polymer composite material, which is the activated carbon composite material, and is referred to as Comparative Example 7.

[0031] Comparative Example 8 differs from Example 1 in that it uses commercially available coconut shell activated carbon, and is referred to as Comparative Example 8.

[0032] The specific surface area and total pore volume of the high specific surface area activated carbon prepared in Examples 1-3 and Comparative Examples 1-2, as well as the commercially available coconut shell activated carbon in Comparative Example 8, were calculated using the nitrogen adsorption-desorption test (BET method). The tests were performed three times, and the average value was taken. The test results are shown in Table 1.

[0033] Table 1. Results of specific surface area and total pore volume measurements for Examples 1-3 and Comparative Examples 1-2 and 8

[0034] As can be seen from the data in Table 1, the embodiments of the present invention achieved a specific surface area and total pore volume that are much higher than those obtained by single activation methods and commercially available activated carbon through the synergistic effect of low-temperature activation with phosphoric acid and high-temperature secondary activation with CO2, proving the successful construction of multi-level interconnected channels.

[0035] The antibacterial activity of Examples 1-3 and Comparative Examples 3-6 against Escherichia coli and Staphylococcus aureus was determined according to GB / T20944.3-2008. The tests were performed three times, and the average value was taken. The antibacterial rate was measured again after the activated carbon composite material was placed in the air for 7 days. The test results are shown in Table 2.

[0036] Table 2. Results of antibacterial rate determination in Examples 1-3 and Comparative Examples 3-6

[0037] As shown in Table 2, the initial antibacterial rates of Examples 1-3 all reached over 98%, and remained above 97% after 7 days, demonstrating the long-term stability brought about by the synergistic antibacterial effect of multiple metals and the protection of the polymer network. The antibacterial rates of Comparative Examples 3 and 4 were significantly lower than those of the Examples, indicating that the introduced Bi... 3+ With Zn 2+ Not only does it possess antibacterial activity, but it can also react with Ni 2+ The formation of a multi-component synergistic antibacterial effect effectively enhances the antibacterial activity. Although Comparative Example 5 has a certain antibacterial activity, it is still lower than that of the ternary synergistic system and Comparative Examples 3-4, proving that the antibacterial efficiency of a single metal is insufficient. Although the initial antibacterial rate of Comparative Example 6 is high, it drops sharply after 7 days, proving that the rigid polymer network plays a crucial role in the sustained-release protection of metal ion release.

[0038] The formaldehyde adsorption performance of the activated carbon composite materials prepared in Examples 1-3, Comparative Examples 1-2, and 6-7, and the commercially available coconut shell activated carbon in Comparative Example 8 were tested three times, and the average value was taken. The results are shown in Table 3.

[0039] The samples from Examples 1-3 and Comparative Examples 1-2 and 6-8 were placed in a container with a formaldehyde concentration of 2 ppm and a volume of 15 ml. 3 In the room, after 24 hours, the formaldehyde concentration C1 was tested using a detection instrument. The formaldehyde adsorption rate is calculated as (1-C1) / C1*100%.

[0040] Table 3. Formaldehyde adsorption performance test results of Examples 1-3 and Comparative Examples 1-2 and 6-8

[0041] As can be seen from the data in Table 3, the formaldehyde adsorption rate of Examples 1-3 all reached over 95%, which is much higher than that of Comparative Example 8 and the other comparative examples. This proves that the high specific surface area hierarchical channels constructed by the two-step activation of phosphoric acid + CO2, as well as the surface porous polymer network, have a strong VOCs capture capacity. The data of Comparative Examples 1-2 show that the adsorption rate decreased significantly due to the lack of CO2 activation and phosphoric acid activation, as the specific surface area and pore volume were lower. This verifies the synergistic necessity of the two-step activation. The data of Comparative Example 6 shows that the polymer network provides additional microporous adsorption sites, which can improve the adsorption capacity. The data of Comparative Example 7 shows that the adsorption rate is between that of Comparative Example 6 and the examples, indicating that the secondary micropores introduced by hypercrosslinking effectively enhance the adsorption capacity.

[0042] It should be understood that those skilled in the art can make improvements or modifications based on the above description, and all such improvements and modifications should fall within the protection scope of the appended claims. Parts not described in detail in this specification are prior art known to those skilled in the art.

Claims

1. A method for preparing a filter-adsorbing activated carbon composite material, characterized by, include: S1: Preparation and pretreatment of high specific surface area activated carbon; After grinding and pulverizing the biomass-based material through an 80-100 mesh sieve, it is mixed with 85wt% wet phosphoric acid in a certain proportion, impregnated and dried, activated in a high-temperature tube furnace under nitrogen atmosphere and then activated again under carbon dioxide atmosphere, and washed and dried to obtain high specific surface area activated carbon. S2: Antibacterial modification of activated carbon; A mixture of nickel chloride hexahydrate ethanol solution, sodium acetate solution, and trisodium citrate solution was added, along with high specific surface area activated carbon, bismuth nitrate pentahydrate, and zinc nitrate hexahydrate. The mixture was then subjected to hydrothermal reaction, washing, drying, and nitrogen atmosphere treatment to obtain antibacterial modified activated carbon. S3: Preparation of activated carbon composite materials; Vinyl hydrotalcite was obtained by reacting it with vinyltriethoxysilane in toluene solution. Then, it was reacted with 1-vinyl-3-butylimidazolium bromide, styrene, and AIBN under an argon atmosphere. After washing and drying, it was reacted with 1,2-dichloroethane, dimethoxymethane, and anhydrous ferric chloride. After centrifugation, washing, Soxhlet extraction, and drying, modified hydrotalcite was obtained. Antibacterial modified activated carbon and modified hydrotalcite were mixed in a mass ratio of 3-5:1 to prepare an activated carbon composite material.

2. The preparation method of the filtering and adsorbing activated carbon composite material according to claim 1, characterized in that, S1: Preparation and pretreatment of high specific surface area activated carbon, specifically including the following steps: S1.1: Grind and pulverize the biomass-based material, then pass it through an 80-100 mesh sieve. Add 40-50 parts by weight of 85wt% wet-process phosphoric acid to 20-30 parts by weight of the biomass-based powder, stir evenly, then impregnate and dry in an oven at 95-100℃ for 2-3 hours. After cooling to room temperature, place it in a high-temperature tube furnace and heat it to 550-600℃ under a nitrogen atmosphere for 1-2 hours. After cooling to room temperature, wash it with deionized water until neutral, and then dry it at 100-120℃ for 10-12 hours to obtain activated biochar. S1.2: Place the activated biochar in a high-temperature tube furnace and heat it to 750-800℃ under a carbon dioxide atmosphere for 1-2 hours. Then cool it to room temperature, wash it with deionized water and dry it to obtain activated carbon with high specific surface area.

3. The method for preparing a filter adsorption activated carbon composite material according to claim 2, characterized in that, The biomass-based material in step S1.1 is one of the following: wood chips, coconut shells, walnut shells, rice husks, straw, and peanut shells.

4. The method for preparing a filter adsorption activated carbon composite material according to claim 2, characterized in that, In step S1.1, the heating rate of the high-temperature tubular furnace is 5-6℃ / min, and the nitrogen flow rate is 80-90mL / min.

5. The method for preparing a filter adsorption activated carbon composite material according to claim 2, characterized in that, In step S1.2, the heating rate of the high-temperature tubular furnace is 5-6℃ / min, and the carbon dioxide flow rate is 100-120mL / min.

6. The method for preparing a filter adsorption activated carbon composite material according to claim 1, characterized in that, S2: Antibacterial modification of activated carbon, specifically including the following steps: S2.1: Add 0.2-0.3 parts by weight of nickel chloride hexahydrate to 25-30 parts by weight of ethanol, and stir at 200-300 rpm for 20-30 min to obtain a nickel chloride hexahydrate ethanol solution. Add 1.4-1.6 parts by weight of sodium acetate to 10-12 parts by weight of deionized water, and stir at 200-300 rpm for 20-30 min to obtain a sodium acetate solution. Add 0.5-0.8 parts by weight of trisodium citrate to 15-20 parts by weight of distilled water, and stir at 200-300 rpm for 20-30 min to obtain a trisodium citrate solution. S2.2: At 30-35℃, mix and stir the nickel chloride hexahydrate ethanol solution, sodium acetate solution, and trisodium citrate solution for 20-30 min. Then add 12-15 parts by weight of high specific surface area activated carbon, 0.3-0.5 parts by weight of bismuth nitrate pentahydrate, and 0.2-0.3 parts by weight of zinc nitrate hexahydrate. After stirring and mixing, transfer to a hydrothermal reactor, seal, and maintain at 140-145℃ for 18-20 h. Cool to room temperature, then wash the product with deionized water and ethanol 3-5 times in sequence. Then dry at 60-70℃ for 4-6 h. Finally, treat at 500-520℃ under nitrogen atmosphere for 2-3 h to obtain antibacterial modified activated carbon.

7. The method for preparing a filter adsorption activated carbon composite material according to claim 1, characterized in that, S3: The preparation of activated carbon composite materials includes the following steps: S3.1: Add 2-3 parts by weight of aluminum hydrotalcite and 10-12 parts by weight of vinyltriethoxysilane to 70-80 parts by weight of toluene solution, then reflux at 80-90℃ for 20-24h, then wash with ethanol and deionized water 3-5 times in sequence, and dry under vacuum to obtain vinylated hydrotalcite. S3.2: Add 1-2 parts by weight of 1-vinyl-3-butylimidazolium bromide to 100-120 parts by weight of N,N-dimethylformamide, stir to dissolve, add 2-3 parts by weight of styrene, continue stirring and mixing for 10-20 min, then add 1-2 parts by weight of vinylized hydrotalcite, sonicate and mix for 5-10 min, then add 0.01-0.03 parts by weight of AIBN, react at 65-70℃ for 28-30 h under argon atmosphere, then wash with ultrapure water and methanol 3-5 times in sequence, and dry under vacuum at 60-80℃ to obtain hydrotalcite-polymer composite material; S3.3: Add 200-230 parts by weight of 1,2-dichloroethane and 25-30 parts by weight of dimethoxymethane to 1-2 parts by weight of the hydrotalcite-polymer composite material, and ultrasonically stir for 5-8 min. Then stir at room temperature for 300-500 rpm for 30-40 min. Then add 5-8 parts by weight of anhydrous ferric chloride, and heat to 80-90℃ for 20-24 h. After the reaction is complete, add excess methanol and stir at 1000-1200 rpm for 10-20 min. Then wash the reactants with methanol and deionized water 3-5 times in sequence. Finally, extract with methanol using a Soxhlet extractor for 12-14 h and vacuum dry at 60-70℃ to obtain modified hydrotalcite. S3.4: Antibacterial modified activated carbon and modified hydrotalcite are mixed at a mass ratio of 3-5:1 at 300-500 rpm for 1-2 hours to prepare activated carbon composite material.

8. A filter adsorption activated carbon composite material, characterized by, It is prepared by the method for preparing a filter adsorption activated carbon composite material according to any one of claims 1-7.

9. The application of the filter adsorption activated carbon composite material according to claim 1 in air filtration, the application including air purification and filtration in the fields of electronics, photovoltaics, medical and health, biopharmaceuticals, food, rail transportation, communication equipment, and shopping malls.

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