Preparation method and application of photocatalytic antibacterial composite material

Abstract

This invention discloses a method for preparing a photocatalytic antibacterial composite material; the method involves using Sn... 4+ / Ga ND reacts with an aqueous solution of sodium carboxymethyl cellulose (CMC) and undergoes hydrothermal sulfidation to induce the formation of tin vacancies. Single-atom Mo is then assembled at these tin vacancies using an impregnation method combined with heat treatment to obtain SAMo-SnS2 / Ga ND powder. Simultaneously, using natural corn stalk cellulose as a substrate, it is dissolved in the ionic liquid BmimCl. ATBPC monomers are grafted onto the cellulose molecular chain using RAFT controlled graft polymerization technology to prepare a cellulose-based cationic polyelectrolyte PATBPC-co-Cellulose solution. The PATBPC-co-Cellulose solution is then blended with the SAMo-SnS2 / Ga ND powder and regenerated with ether to form a composite antibacterial material. This composite material has shown high efficiency and long-lasting bactericidal activity in antibacterial experiments against multidrug-resistant Escherichia coli and methicillin-resistant Staphylococcus aureus under both light and dark conditions, demonstrating promising application prospects.

Description

Technical Field

[0001] This invention relates to a method for preparing a photocatalytic antibacterial composite material and its application in the preparation of agents that inhibit drug-resistant bacteria. Background Technology

[0002] The overuse of antibiotics has led to an increase in drug-resistant bacterial strains, posing a serious threat to human health and daily life. The contamination by drug-resistant bacteria has attracted significant global attention. Against this backdrop, the development of novel non-antibiotic bactericides that combine low toxicity and high efficacy is particularly important. Quaternary ammonium compounds (QACs), as cationic bactericides, possess rapid bactericidal ability and broad-spectrum antibacterial activity; however, their overuse and slow biodegradability have led to a sharp increase in bacterial resistance to QACs. Quaternary phosphine salts (QPSs) share many similarities with QACs, but the QPS group benefits from the larger atomic radius and lower electronegativity of the phosphorus atom, endowing it with stronger polarization properties and more efficient antibacterial activity. Furthermore, QPSs exhibit higher chemical stability and excellent antioxidant properties, and possess lower toxicity, making them suitable for various applications, including extreme environments. Based on these characteristics, QPSs hold promise as a next-generation cationic bactericide.

[0003] Against the backdrop of increasingly severe global environmental problems and the near depletion of non-renewable resources such as oil, the development and utilization of natural renewable resources has attracted great attention from the international community. As the most abundant natural polymer on Earth, cellulose is widely distributed in plant cell walls, bacterial biofilms, and marine biomass. Corn stalks, a major by-product of my country's grain production, are traditionally disposed of primarily through open-air burning, which typically leads to environmental pollution and the ineffective loss of cellulose resources. Corn stalks belong to the Poaceae family and are rich in thin-walled cellulose, possessing a high specific surface area, abundant cell cavities, and a loose supramolecular structure. These characteristics contribute to good accessibility to chemical reagents. However, the application of cellulose as a carrier for antibacterial materials is currently limited. Filling this gap could simultaneously achieve the synergistic effect of waste resource recycling and economic growth.

[0004] Reversible addition-fragmentation chain transfer (RAFT) polymerization is a novel living radical polymerization method for synthesizing graft polymers with well-defined structures. Compared to other living radical polymerization techniques, the main advantage of the RAFT process is its ability to polymerize a wide range of vinyl monomers in a controlled manner under relatively mild reaction conditions. The RAFT polymerization process is as follows: First, an initiator such as azobisisobutyronitrile (AIBN) decomposes at a suitable temperature to generate free radicals. These free radicals then initiate the monomer to generate chain-growing free radicals Pn·. Pn· undergoes C=S addition with chain transfer agent 1 to generate an intermediate addition product 2. This intermediate product is unstable and can generate a dormant species 3 and a re-initiating free radical R·. R· can re-initiate the monomer to generate Pm·. This active species can then undergo the above chain transfer process to regenerate the active species Pn· and the dormant species 4. This cycle continues until the chain transfer agent is consumed, thus establishing an equilibrium between the chain-growing free radicals Pm· and Pn· and the dormant species 3 and 4, making the reaction rate controllable and achieving the goal of controlling the entire polymerization reaction.

[0005] Photocatalysis is an eco-friendly disinfection technology that has shown significant application potential in wastewater treatment, air purification, and other fields. Despite its significant advantages, photocatalytic disinfection technology still faces challenges such as low light absorption and utilization efficiency and high recombination rates of photogenerated carriers. To address these limitations, researchers have proposed various improvement strategies, including constructing heterojunctions and elemental doping. These strategies have significantly improved the disinfection efficiency of photocatalytic materials under natural light conditions. Summary of the Invention

[0006] This invention provides a method for preparing a photocatalytic antibacterial composite material. The method involves grafting quaternary phosphonium salt monomers onto cellulose chains via RAFT polymerization, followed by loading single-atom composite photocatalytic nanoparticles. The resulting material exhibits highly efficient and long-lasting bactericidal properties under both light and dark conditions, serving as a highly effective antibacterial agent against multidrug-resistant Escherichia coli and methicillin-resistant Staphylococcus aureus. Applying this material to the antibacterial field can reduce or even eliminate the potential harm of drug-resistant bacteria to human health and the living environment.

[0007] The specific steps of the method of the present invention are as follows: (1) Liquid gallium metal was added to an aqueous solution of Sn salt, ultrasonically dispersed, and the mixture was dried at 90~130℃ to obtain Sn. 4+ / Ga ND precursor; The precursor was dispersed in deionized water, ultrasonically treated, and then reacted with sodium carboxymethyl cellulose (CMC) aqueous solution. Then Na2S solution was added, mixed evenly, and transferred to a hydrothermal reactor. The reaction was carried out at 100~240℃ for 4~10h. The reaction product was dispersed in diethyl ether and washed. Solid-liquid separation was performed, and the solid was dried to obtain CMC / Sv-SnS2 / Ga ND. CMC / Sv-SnS2 / Ga ND was dispersed in diethyl ether, and MoCl5 diethyl ether solution was slowly added dropwise. After impregnation, the mixture was dried and treated at 1000~1500℃ for 1~3h under an inert atmosphere to obtain SAMo-SnS2 / Ga ND powder. The mass concentration of the sodium carboxymethyl cellulose aqueous solution is 0.01~1.00%; Sn 4+ The molar ratio of Sn to Ga is 1:0.1~0.2; 4+ With S 2- The molar ratio is 1:1.5~2.5; the mass-to-volume ratio of Ga to sodium carboxymethyl cellulose aqueous solution (g:mL) is 1:30~100; the mass-to-volume ratio of CMC / Sv-SnS2 / GaND to MoCl5 ether solution (g:mL) is 1:5~10; and the concentration of MoCl5 ether solution is 0.05~0.2mol / L. (2) Acryloyl chloride and tributylphosphine were placed in a round-bottom flask, acetone was added, and the mixture was reacted at 60-120°C for 24-72 h under an inert atmosphere. After cooling to room temperature, diethyl ether was added to precipitate the precipitate. The precipitate was filtered, washed, and dried under vacuum to obtain acryloyltributyl quaternary phosphonium chloride. The molar ratio of acryloyl chloride to tributylphosphine is 1:1.0~2.5; (3) Add corn straw cellulose powder with a degree of polymerization of 700~1000 to 1-butyl-3-methylimidazolium chloride (BmimCl) dissolved at 80~110℃ and react at 80~110℃ for 2~6h to obtain cellulose solution; under an inert atmosphere, add pyridine and 2-chloro-2-phenylacetyl chloride (CPAC) to cellulose solution and react at 50~90℃ for 24~72h. After high-speed shearing of the reaction product in diethyl ether, the solid and liquid are separated, and the solid is washed with deionized water, dried and freeze-ground to obtain Cell-CPAC powder. The corn stalk cellulose powder was prepared according to the method described in the literature "Improved thermal stability of regenerated cellulose films from corn (Zeamays) stalk pith using facile preparation with low-concentration zinc chloride dissolving"; the mass-to-volume ratio of corn stalk cellulose powder to pyridine was 1:7~13 (g:mL), and the mass-to-volume ratio of corn stalk cellulose powder to 2-chloro-2-phenylacetyl chloride was 1:6~12 (g:mL). CS2 was added dropwise to phenyl magnesium chloride under an inert atmosphere and ice-water bath conditions, and the reaction was carried out at 40-70℃ for 3-5 hours to obtain phenylthio-magnesium chloride. The molar ratio of phenyl magnesium chloride to CS2 is 1:2~7; Cell-CPAC solution (using 1-butyl-3-methylimidazolium chloride dissolved at 80-110℃ as solvent) was added to phenylthiomagnesium chloride and reacted at 80-100℃ for 24-48h. The reaction product was subjected to high-speed shearing and regeneration in diethyl ether, followed by solid-liquid separation. The solid diethyl ether was washed, dried, and freeze-ground to obtain Cell-CTA powder. Cell-CTA powder was added to 1-butyl-3-methylimidazolium chloride dissolved at 80-110℃ under an inert atmosphere. Acryloyltributyl quaternary phosphonium chloride (ATBPC) and azobisisobutyronitrile (AIBN) were added, and the reaction was carried out at 60-80℃ for 4-8h. The reaction was terminated by cooling in an ice-water bath to obtain a cellulose-based cationic polyelectrolyte PATBPC-co-Cellulose solution. The mass-to-volume ratio (g:mL) of Cell-CPAC powder to phenyl magnesium chloride is 1:1~1.5; the mass ratio of Cell-CTA powder to acryloyltributyl quaternary phosphonium chloride is 1:4~8; and the mass ratio of Cell-CTA powder to azobisisobutyronitrile is 1:0.01~0.05. (4) Disperse the SAMo-SnS2 / GaND powder from step (1) in PATBPC-co-Cellulose solution, mix evenly, regenerate in diethyl ether, separate solid and liquid, wash solid, and vacuum dry to obtain photocatalytic antibacterial composite material.

[0008] Another objective of this invention is to apply the photocatalytic antibacterial composite material prepared by the above method in the preparation of agents to inhibit drug-resistant bacteria, wherein the drug-resistant bacteria are multidrug-resistant Escherichia coli (ESC). 多重耐药性大肠杆菌 大肠杆菌 ), methicillin-resistant Staphylococcus aureus (MRSA) 耐甲氧西林金黄色葡萄球菌 ).

[0009] The beneficial effects of this invention are: This invention utilizes the CMC carboxyl anion to target Sn 4+ The adsorption effect of Sn 4+ Tin vacancies were induced on the / Ga ND layer, and single-atom Mo was precisely assembled at these vacancy sites, successfully preparing SAMo-SnS2 / Ga ND composite nanoparticles. Using natural high-molecular-weight cellulose as a substrate, the intramolecular and intermolecular hydrogen bond network of cellulose was effectively disrupted through BmimCl dissolution treatment, resulting in a uniformly distributed chain morphology of cellulose and significantly improving reaction accessibility. Based on this, ATBPC monomers were grafted onto the cellulose molecular chains using RAFT controlled graft copolymerization technology, successfully preparing a well-defined cellulose-based cationic polyelectrolyte PATBPC-co-Cellulose. The PATBPC-co-Cellulose solution was regenerated by adding it to an ether dispersion of SAMo-SnS2 / Ga ND powder, allowing photocatalytic nanoparticles to be uniformly loaded onto the porous surface of the cellulose polymer. The large specific surface area of ​​the cellulose polymer not only provides abundant active sites for the photocatalyst but also effectively promotes interfacial charge transfer, significantly enhancing the photocatalytic performance of the composite material. Under light conditions, this composite material exhibits excellent antibacterial activity. Even in the absence of light, it continues to exert its bactericidal effect through the contact mechanism of quaternary phosphonium salts. The quaternary phosphonium salts on the cellulose-based cationic polyelectrolyte adsorb negatively charged bacterial cells via electrostatic interactions, inserting hydrophobic alkyl groups into the cell membrane, leading to membrane structure disruption and leakage of cell contents, thereby achieving a highly efficient and long-lasting bactericidal effect. This composite material utilizes widely available, low-cost, non-toxic, and environmentally friendly raw materials, opening up new avenues for the high-value utilization of cellulose. It also shows broad application prospects in the control of drug-resistant bacterial contamination, potentially reducing antibiotic use and its potential harm to the environment and human health. Attached Figure Description

[0010] Figure 1 The results of the antibacterial test using the plate coating method in Example 1 are as follows; Figure 2 The results of the antibacterial test using the plate coating method in Example 2 are as follows; Figure 3 The results of the antibacterial test using the plate coating method in Example 3 are shown. Detailed Implementation

[0011] The present invention will be further described in detail below with reference to the embodiments, but the scope of protection of the present invention is not limited to the content described. Unless otherwise specified, the methods used in this embodiment are conventional methods, and the reagents used are conventional reagents unless otherwise specified. In the examples, the multidrug-resistant Escherichia coli was purchased from Nuoan Gene Technology Co., Ltd., and the methicillin-resistant Staphylococcus aureus was purchased from Hunan Fenghui Biotechnology Co., Ltd. Example 1

[0012] (1) Weigh out CMC with a viscosity of 2500~4500 mPa·s and dissolve it in deionized water to obtain a 0.1% CMC aqueous solution; add 0.11 g Ga to 50 mL of 0.2 mol / L SnCl4·5H2O aqueous solution and stir ultrasonically for 15 min. Dry the mixture at 95 °C to obtain Sn. 4+ / Ga ND; will Sn 4+ / GaND was ultrasonically dispersed in 40 mL of deionized water for 15 min to obtain Sn 4+ / GaND dispersion; the dispersion was added to 10 mL of CMC aqueous solution and stirred at 300 rad / min for 1 h at room temperature. Then, 80 mL of 0.2 mol / L Na2S solution was added, mixed thoroughly, and transferred to a hydrothermal reactor. The reaction was carried out hydrothermally at 100 °C for 8 h. The hydrothermal reactants were dispersed in diethyl ether, washed, and subjected to solid-liquid separation. After drying, the solid was used to form CMC / Sv-SnS2 / GaND powder; wherein Sn 4+ The molar ratio of Sn to Ga is 1:0.158. 4+ With S 2- The molar ratio is 1:1.6, and the mass-volume ratio of Ga to sodium carboxymethyl cellulose aqueous solution (g:mL) is 1:90.9. (2) Weigh 1.48g of CMC / Sv-SnS2 / Ga ND powder and ultrasonically disperse it in 28mL of diethyl ether. Add 10mL of 0.05mol / L MoCl5 diethyl ether solution and stir continuously to impregnate the powder. After drying, heat treat it in an inert atmosphere at 1000℃ for 3h in a tube furnace to obtain SAMo-SnS2 / Ga ND powder. The mass-volume ratio of CMC / Sv-SnS2 / Ga ND to MoCl5 diethyl ether solution is 1:6.75 (g:mL). (3) Weigh 5 mL of acryloyl chloride and 27.6 mL of tributylphosphine into a round-bottom flask, add 100 mL of acetone, and react at 60 °C for 24 h under an inert atmosphere. After the reaction is complete, cool the mixture to room temperature, add 150 mL of diethyl ether to precipitate the solid, separate the solid and liquid, wash the solid with diethyl ether, and dry it under vacuum for 24 h to obtain acryloyltributyl quaternary phosphonium chloride (ATBPC). The molar ratio of acryloyl chloride to tributylphosphine is 1:1.84. (4) 1g of corn stalk cellulose powder with a degree of polymerization of 700~1000 was added to 30g of BmimCl dissolved at 80℃ and reacted at 80℃ for 5h; in an inert atmosphere, 9mL of pyridine and 8.2mL of CPAC were added to the cellulose solution and reacted at 50℃ at 200rad / min for 60h. The reaction product was subjected to high-speed shearing in 130mL of diethyl ether at 5mL / min and 3500rad / min to separate the solid and liquid. The solid was filtered and washed with deionized water (5×150mL), dried and freeze-ground to obtain Cell-CPAC powder; the mass-volume ratio of corn stalk cellulose powder to pyridine was 1:9 g:mL and the mass-volume ratio of corn stalk cellulose powder to CPAC was 1:8.2 g:mL. Under an inert atmosphere and in an ice-water bath, 1.3 mL of phenyl magnesium chloride was added to a round-bottom flask, followed by the dropwise addition of 0.8 mL of CS2. After the addition, the temperature was raised to 40 °C and the reaction was carried out for 5 h to obtain phenylthiomagnesium chloride. Cell-CPAC solution (prepared using 1-butyl-3-methylimidazolium chloride dissolved at 80 °C as solvent) was added to the phenylthiomagnesium chloride and the reaction was carried out at 80 °C for 40 h. The reaction product was subjected to high-speed shearing at 5 mL / min and 3500 rad / min in 130 mL of diethyl ether for solid-liquid separation. The solid was washed by filtration in diethyl ether (5 × 150 mL), dried, and freeze-ground to obtain Cell-CTA powder. The mass ratio of BmimCl to Cell-CPAC powder was 30:1, the molar ratio of phenyl magnesium chloride to CS2 was 1:5, and the mass-volume ratio of Cell-CPAC powder to phenyl magnesium chloride (g:mL) was 1:1.3. (5) In an inert atmosphere, weigh 1g of Cell-CTA powder and add 30g of BmimCl dissolved at 80℃, along with 5.5g of ATBPC and 0.01g of AIBN. After reacting at 60℃ for 8h, stop the reaction by cooling the reaction flask in an ice-water bath to obtain a PATBPC-co-Cellulose solution; wherein the mass ratio of BmimCl to Cell-CTA powder is 30:1, the mass ratio of Cell-CTA powder to ATBPC is 1:5.5, and the mass ratio of Cell-CTA powder to AIBN is 1:0.01. The SAMo-SnS2 / GaND powder obtained in step (2) was dispersed in PATBPC-co-Cellulose solution, mixed evenly, regenerated and washed in ether, separated from the solid, and dried under vacuum to obtain a dark brown PATBPC-co-Cellulose / SAMo-SnS2 / GaND composite antibacterial material.

[0013] (6) Applying PATBPC-co-Cellulose / SAMo-SnS2 / GaND composite antibacterial material to multidrug-resistant Escherichia coli ( 多重耐药性大肠杆菌 ), methicillin-resistant Staphylococcus aureus (MRSA) 耐甲氧西林金黄色葡萄球菌 The antibacterial activity of the material was assessed using the plate coating method (referring to GB21551 2-2010 standard), with an initial bacterial concentration of 10. 8 CFU / mL. Results of the antibacterial test using the plate coating method are shown below. Figure 1 At 300mW / cm 2 After 30 minutes of xenon lamp irradiation, the composite material showed resistance to multidrug-resistant Escherichia coli (M. coli). 多重耐药性大肠杆菌 The logarithmic removal rate (LRV) of 7.3 was achieved against methicillin-resistant Staphylococcus aureus (MRSA). 耐甲氧西林金黄色葡萄球菌 The LRV (Liquidity Ratio) of the composite material reached 6.5. Even under dark conditions, its LRV against multidrug-resistant Escherichia coli remained at 5.4, and against methicillin-resistant Staphylococcus aureus (MRSA) at 4.8. Analysis of the antibacterial mechanism showed that under light conditions, the bactericidal effect of the composite material mainly stemmed from the oxidative damage to bacterial cells caused by photocatalytically generated reactive oxygen species (ROS); while under dark conditions, its antibacterial activity mainly depended on the broad-spectrum contact bactericidal properties of the quaternary phosphonium salt component. This composite material possesses both photocatalytic and contact bactericidal mechanisms, achieving efficient bacterial elimination in all weather conditions and demonstrating promising application prospects. Example 2

[0014] (1) Weigh out CMC with a viscosity of 2500~4500 mPa·s and dissolve it in deionized water to obtain a 0.5% CMC aqueous solution; add 0.53g Ga to 120mL of 0.5mol / L SnCl4·5H2O aqueous solution and stir ultrasonically for 30min. Dry the mixture at 105℃ to obtain Sn. 4+ / Ga ND; will Sn 4+ / GaND was sonicated in 80 mL of deionized water for 30 min to obtain Sn. 4+ / GaND dispersion; the dispersion was added to 20 mL of CMC aqueous solution and stirred at 400 rad / min for 1.5 h at room temperature. Then, 200 mL of 0.5 mol / L Na2S solution was added, mixed thoroughly, and transferred to a hydrothermal reactor. The reaction was carried out at 150 °C for 6 h. The reaction product was dispersed in diethyl ether, washed, and subjected to solid-liquid separation. After drying, the solid was used to form CMC / Sv-SnS2 / GaND powder, in which Sn 4+ The molar ratio of Sn to Ga is 1:0.1267. 4+ With S 2- The molar ratio is 1:1.667, and the mass-volume ratio of Ga to CMC aqueous solution (g:mL) is 1:37.74. (2) Weigh 2.25 g of CMC / Sv-SnS2 / Ga ND powder and ultrasonically disperse it in 50 mL of diethyl ether. Add 15 mL of 0.1 mol / L MoCl5 diethyl ether solution and stir continuously to impregnate the powder. After drying, heat treat it in an inert atmosphere at 1300 °C for 1.5 h in a tube furnace to obtain SAMo-SnS2 / Ga ND powder. The mass-volume ratio of CMC / Sv-SnS2 / Ga ND to MoCl5 diethyl ether solution is 1:6.67 (g:mL). (3) Weigh 8 mL of acryloyl chloride and 49.1 mL of tributylphosphine into a round-bottom flask, add 200 mL of acetone, and react at 80 °C for 30 h in an inert atmosphere; after the reaction is completed, cool the mixture to room temperature, add 250 mL of diethyl ether to precipitate, separate the solid and liquid, wash the solid with diethyl ether, and dry under vacuum for 34 h to obtain ATBPC; the molar ratio of acryloyl chloride to tributylphosphine is 1:2.04; (4) 2g of corn stalk cellulose powder with a degree of polymerization of 700~1000 was added to 68g of BmimCl dissolved at 90℃ and reacted at 90℃ for 2.5 h; under an inert atmosphere, 19.6 mL of pyridine and 19.3 mL of CPAC were added to the cellulose solution and reacted at 70℃ at 300 rad / min for 30 h. The reaction product was subjected to high-speed shearing at 6 mL / min and 4000 rad / min in 160 mL of diethyl ether to separate the solid and liquid. The solid was filtered and washed with deionized water (5×150 mL), dried and freeze-ground to obtain Cell-CPAC powder; the mass-volume ratio of corn stalk cellulose powder to pyridine was 1:9.8 g:mL and the mass-volume ratio of corn stalk cellulose powder to CPAC was 1:9.65 g:mL. Under an inert atmosphere and in an ice-water bath, 2.55 mL of phenyl magnesium chloride was added to a round-bottom flask, followed by the dropwise addition of 0.93 mL of CS2. After the addition, the temperature was raised to 50 °C and the reaction was carried out for 4 h to obtain phenylthiomagnesium chloride. Cell-CPAC solution (prepared using 1-butyl-3-methylimidazolium chloride dissolved at 90 °C as solvent) was added to the phenylthiomagnesium chloride and the reaction was carried out at 90 °C for 30 h. The reaction product was subjected to high-speed shearing at 5 mL / min and 3500 rad / min in diethyl ether to separate the solid and liquid. The solid was then filtered and washed with diethyl ether (5 × 150 mL), dried, and freeze-ground to obtain Cell-CTA powder. The mass ratio of BmimCl to Cell-CPAC powder was 34:1, the molar ratio of phenyl magnesium chloride to CS2 was 1:3.02, and the mass-volume ratio of Cell-CPAC powder to phenyl magnesium chloride (g:mL) was 1:1.275.

[0015] (5) In an inert atmosphere, weigh 2g of Cell-CTA powder and add it to 68g of BmimCl dissolved at 90℃, and add 13.5g of ATBPC and 0.05g of AIBN. After reacting at 70℃ for 6h, cool the reaction flask in an ice-water bath to stop the reaction and obtain PATBPC-co-Cellulose solution; wherein the mass ratio of BmimCl to Cell-CTA powder is 34:1, the mass ratio of Cell-CTA powder to ATBPC is 1:6.75, and the mass ratio of Cell-CTA powder to AIBN is 1:0.025; The SAMo-SnS2 / GaND powder obtained in step (2) was dispersed in PATBPC-co-Cellulose solution, mixed evenly, regenerated and washed in ether, separated from solid and liquid, and vacuum dried to obtain a dark brown PATBPC-co-Cellulose / SAMo-SnS2 / GaND composite antibacterial material. (6) The prepared PATBPC-co-Cellulose / SAMo-SnS2 / GaND composite antibacterial material was applied to the antibacterial test of multidrug-resistant Escherichia coli and methicillin-resistant Staphylococcus aureus. The method was the same as in Example 1. The antibacterial test results of the plate coating method are shown in […]. Figure 2 At 300mW / cm 2 After 30 minutes of xenon lamp irradiation, the composite material achieved an LRV of 7.5 against multidrug-resistant Escherichia coli and an LRV of 6.8 against methicillin-resistant Staphylococcus aureus. Under dark conditions, its LRV against multidrug-resistant Escherichia coli remained at 6.9, and its LRV against methicillin-resistant Staphylococcus aureus reached 5.9. Example 3

[0016] (1) Weigh out CMC with a viscosity of 2500~4500 mPa·s and dissolve it in deionized water to obtain a 1% CMC aqueous solution; add 0.94g Ga to 200 mL of 0.6mol / L SnCl4·5H2O aqueous solution and stir ultrasonically for 45 min. Dry the mixture at 115℃ to obtain Sn. 4+ / Ga ND; will Sn 4+ / GaND was sonicated in 150 mL of deionized water for 40 min to obtain Sn. 4+ / GaND dispersion; the dispersion was added to 30 mL of CMC aqueous solution and stirred at 450 rad / min for 2 h at room temperature. Then, 450 mL of 0.5 mol / L Na2S solution was added, mixed thoroughly, and transferred to a hydrothermal reactor. The reaction was carried out at 200 °C for 6.5 h. The reaction product was dispersed in diethyl ether, washed, and subjected to solid-liquid separation. After drying, the solid was used to form CMC / Sv-SnS2 / GaND powder, in which Sn4+ The molar ratio of Sn to Ga is 1:0.1123. 4+ With S 2- The molar ratio is 1:1.875, and the mass-volume ratio of Ga to CMC aqueous solution (g:mL) is 1:31.91. (2) Weigh 2.4 g of CMC / Sv-SnS2 / Ga ND powder and ultrasonically disperse it in 55 mL of diethyl ether. Add 20 mL of 0.15 mol / L MoCl5 diethyl ether solution dropwise and stir continuously to impregnate the powder. After drying, heat treat it in an inert atmosphere at 1500 °C for 1 h in a tube furnace to obtain SAMo-SnS2 / Ga ND powder. The mass-to-volume ratio of CMC / Sv-SnS2 / Ga ND to MoCl5 diethyl ether solution is 1:8.33 (g:mL). (3) Weigh 10 mL of acryloyl chloride and 67.5 mL of tributylphosphine into a round-bottom flask, add 250 mL of acetone, and react at 70 °C for 25 h in an inert atmosphere; after the reaction is completed, cool the mixture to room temperature, add 300 mL of diethyl ether to precipitate, separate the solid and liquid, wash the solid with diethyl ether, and dry under vacuum for 42 h to obtain ATBPC, in which the molar ratio of acryloyl chloride and tributylphosphine is 1:2.25; (4) 3g of corn stalk cellulose powder with a degree of polymerization of 700~1000 was added to 96g of BmimCl dissolved at 100℃ and heated at 100℃ for 2h; under an inert atmosphere, 31.5mL of pyridine and 28.7mL of CPAC were added to the cellulose solution and reacted at 80℃ with a rotation speed of 350rad / min for 30h. The reaction product was subjected to high-speed shearing in 180mL of diethyl ether at 7mL / min and 4500rad / min to separate the solid and liquid. The solid was filtered and washed with deionized water (5×150 mL), dried and freeze-ground to obtain Cell-CPAC powder; the mass-volume ratio of corn stalk cellulose powder to pyridine was 1:10.5 g:mL and the mass-volume ratio of corn stalk cellulose powder to CPAC was 1:9.57 g:mL. Under an inert atmosphere and in an ice-water bath, 3.8 mL of phenyl magnesium chloride was added to a round-bottom flask, followed by the dropwise addition of 1.34 mL of CS2. After the addition, the temperature was raised to 50 °C and the reaction was carried out for 4 h to obtain phenylthiomagnesium chloride. Cell-CPAC solution (prepared using 1-butyl-3-methylimidazolium chloride dissolved at 100 °C as solvent) was added to the phenylthiomagnesium chloride and the reaction was carried out at 95 °C for 24 h. The reaction product was subjected to high-speed shearing at 5 mL / min and 3500 rad / min in diethyl ether to separate the solid and liquid. The solid was then filtered and washed with diethyl ether (5 × 150 mL), dried, and freeze-ground to obtain Cell-CTA powder. The mass ratio of BmimCl to Cell-CPAC powder was 32:1, the molar ratio of phenyl magnesium chloride to CS2 was 1:2.92, and the mass-volume ratio of Cell-CPAC powder to phenyl magnesium chloride (g:mL) was 1:1.27. (5) In an inert atmosphere, weigh 3g of cell-CTA powder, add it to 96g of BmimCl dissolved at 100℃, and add 18.7g of ATBPC and 0.09mL of AIBN. After reacting at 70℃ for 5h, cool the reaction flask in an ice-water bath to stop the reaction and obtain PATBPC-co-Cellulose solution; wherein the mass ratio of BmimCl to Cell-CTA powder is 32:1, the mass ratio of Cell-CTA powder to ATBPC is 1:6.23, and the mass ratio of Cell-CTA powder to AIBN is 1:0.03; The SAMo-SnS2 / GaND powder obtained in step (2) was dispersed in PATBPC-co-Cellulose solution, mixed evenly, regenerated and washed in ether, separated from the solid, and vacuum dried to obtain a dark brown PATBPC-co-Cellulose / SAMo-SnS2 / GaND composite antibacterial material.

[0017] (6) The prepared PATBPC-co-Cellulose / SAMo-SnS2 / GaND composite antibacterial material was applied to the antibacterial test of multidrug-resistant Escherichia coli and methicillin-resistant Staphylococcus aureus. The method was the same as above. The results of the antibacterial test by plate coating method are shown in […]. Figure 3 At 300mW / cm 2 After 30 minutes of xenon lamp irradiation, the composite material exhibited an LRV of 8.4 against multidrug-resistant Escherichia coli and an LRV of 7.8 against methicillin-resistant Staphylococcus aureus. Under dark conditions, its LRV against multidrug-resistant Escherichia coli remained at 7.1, and its LRV against methicillin-resistant Staphylococcus aureus reached 6.4.

Claims

1. A method for preparing a photocatalytic antibacterial composite material, characterized in that, The steps are as follows: (1) Liquid gallium metal was added to an aqueous solution of Sn salt, ultrasonically dispersed, and dried to obtain Sn. 4+ / GaND precursor; the precursor was dispersed in deionized water, ultrasonically treated, and then reacted with sodium carboxymethyl cellulose aqueous solution. Then Na2S solution was added, mixed evenly, and transferred to a hydrothermal reactor. The reaction was carried out at 100~240℃ for 4~10h. The reaction product was dispersed in diethyl ether and washed. Solid-liquid separation was performed, and the solid was dried to obtain CMC / Sv-SnS2 / GaND. CMC / Sv-SnS2 / GaND was dispersed in diethyl ether, and MoCl5 diethyl ether solution was slowly added dropwise. After impregnation, it was dried and treated at 1000~1500℃ for 1~3h under an inert atmosphere to obtain SAMo-SnS2 / GaND powder. (2) Acryloyl chloride and tributylphosphine were placed in a round-bottom flask, acetone was added, and the mixture was reacted at 60-120°C for 24-72 h under an inert atmosphere. After cooling to room temperature, diethyl ether was added to precipitate the precipitate. The precipitate was filtered, washed, and dried under vacuum to obtain acryloyltributyl quaternary phosphonium chloride. (3) Add corn straw cellulose powder with a degree of polymerization of 700~1000 to 1-butyl-3-methylimidazolium chloride dissolved at 80~110℃ and react at 80~110℃ for 2~6h to obtain cellulose solution; under an inert atmosphere, add pyridine and 2-chloro-2-phenylacetyl chloride to cellulose solution and react at 50~90℃ for 24~72h. After high-speed shearing of the reaction product in diethyl ether, solid-liquid separation is performed. The solid is washed with deionized water, dried and freeze-ground to obtain Cell-CPAC powder. CS2 was added dropwise to phenyl magnesium chloride under an inert atmosphere and ice-water bath conditions, and the reaction was carried out at 40-70℃ for 3-5 hours to obtain phenylthio-magnesium chloride. Cell-CPAC solution was added to phenylthiomagnesium chloride and reacted at 80-100℃ for 24-48h. The reaction product was subjected to high-speed shearing and regeneration in diethyl ether, followed by solid-liquid separation. The solid diethyl ether was washed, dried, and freeze-ground to obtain Cell-CTA powder. Cell-CTA powder was added to 1-butyl-3-methylimidazolium chloride dissolved at 80-110℃ under an inert atmosphere. Acryloyltributyl quaternary phosphonium chloride and azobisisobutyronitrile were added, and the reaction was carried out at 60-80℃ for 4-8h. The reaction was terminated by cooling in an ice-water bath to obtain a cellulose-based cationic polyelectrolyte PATBPC-co-Cellulose solution. (4) Disperse the SAMo-SnS2 / GaND powder from step (1) in PATBPC-co-Cellulose solution, mix evenly, regenerate in diethyl ether, separate solid and liquid, wash solid, and vacuum dry to obtain photocatalytic antibacterial composite material.

2. The method for preparing the photocatalytic antibacterial composite material according to claim 1, characterized in that: The mass concentration of sodium carboxymethyl cellulose aqueous solution is 0.01~1.00%; Sn 4+ The molar ratio of Sn to Ga is 1:0.1~0.2; 4+ With S 2- The molar ratio is 1:1.5~2.5; the mass-to-volume ratio of Ga to sodium carboxymethyl cellulose aqueous solution (g:mL) is 1:30~100; the mass-to-volume ratio of CMC / Sv-SnS2 / GaND to MoCl5 ether solution (g:mL) is 1:5~10; and the concentration of MoCl5 ether solution is 0.05~0.2mol / L.

3. The method for preparing the photocatalytic antibacterial composite material according to claim 1, characterized in that: The molar ratio of acryloyl chloride to tributylphosphine is 1:1.0~2.

5.

4. The method for preparing the photocatalytic antibacterial composite material according to claim 1, characterized in that: The mass-to-volume ratio of corn stalk cellulose powder to pyridine (g:mL) is 1:7~13, and the mass-to-volume ratio of corn stalk cellulose powder to 2-chloro-2-phenylacetyl chloride (g:mL) is 1:6~12.

5. The method for preparing the photocatalytic antibacterial composite material according to claim 1, characterized in that: Cell-CPAC dissolution solution uses 1-butyl-3-methylimidazolium chloride dissolved at 80~110℃ as the solvent.

6. The method for preparing the photocatalytic antibacterial composite material according to claim 1, characterized in that: The molar ratio of phenyl magnesium chloride to CS2 is 1:2~7, the mass-volume ratio of Cell-CPAC powder to phenyl magnesium chloride (g:mL) is 1:1~1.5; the mass ratio of Cell-CTA powder to acryloyltributyl quaternary phosphonium chloride is 1:4~8, and the mass ratio of Cell-CTA powder to azobisisobutyronitrile is 1:0.01~0.

05.

7. The application of the photocatalytic antibacterial composite material prepared by the method of any one of claims 1-6 in the preparation of agents that inhibit drug-resistant bacteria.

8. The application according to claim 7, characterized in that: Drug-resistant bacteria include multidrug-resistant Escherichia coli (M. coli). Multidrug- resistant Escherichia coli ), methicillin-resistant Staphylococcus aureus (MRSA) Methicillin-resistant Staphylococcus aureus ).

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