A copper-based disinfectant composite functional membrane material, its preparation method and application

Abstract

The present invention discloses a copper-based disinfectant composite functional membrane material, its preparation method and application. The preparation method includes the following steps: preparing zinc indium sulfide composite material ZIS by hydrothermal method, preparing a copper ion solution and mixing the composite material for photodeposition reaction to obtain copper-based disinfectant CZIS; functionalizing acidified carbon nanotubes with polyethyleneimine and combining with vacuum-assisted filtration method to deposit CNTs on a hydrophilic polyvinylidene fluoride membrane to form a thin film; filtering the CZIS dispersion on the CNTs-PEI membrane to obtain the copper-based disinfectant composite functional membrane material CNTs-PEI / CZIS. The CNTs-PEI / CZIS composite membrane of the present invention can achieve efficient disinfection of bacteria, with the antibacterial ability approaching 100% within 2 h (bacterial concentration ≥ 10<supgt;6< / supgt> CFU / mL), and has high stability, can be recycled, has self-cleaning and broad-spectrum applicability, and has good environmental purification potential. It is a multifunctional membrane material integrating high-efficiency sterilization and self-cleaning.

Description

Technical Field

[0001] The present invention belongs to the technical field of the preparation of bactericidal composite functional materials, and particularly relates to a copper-based disinfectant composite functional membrane material, a preparation method thereof and an application thereof. Background Art

[0002] Water resource security is a major issue related to human health and social development. Antibiotics are effective drugs for treating bacterial infections. However, due to the abuse of antibiotics, more and more bacteria have developed drug resistance, and some bacteria have even acquired multi-drug resistance, resulting in the widespread presence of drug-resistant bacteria in water systems, posing a great threat to human health. Traditional disinfection technologies such as chlorine, ozone and ultraviolet light have problems such as disinfection by-products, low energy efficiency and high costs. Nanomaterials can achieve bactericidal effects by destroying cell structures, affecting cell metabolism, etc., and have the advantages of high efficiency, safety and long lifespan, and are considered the most promising new method in the field of disinfection.

[0003] Copper and copper-based compounds have been known as disinfectants since ancient times. Copper nanoparticles (CuNPs) in the form of nanoparticles have a larger surface area to volume ratio, increasing antibacterial properties while improving optical properties. However, the instability of CuNPs due to easy oxidation in air or water media will cause their loss. Synthesizing composite materials is one of the most effective strategies to solve the problem of metal stability, and can also improve catalytic performance through the synergistic effect between components and be applied to environmental disinfection. As an advanced functional material, ternary sulfide ZnIn2S4 has excellent chemical stability, visible light absorption performance and good photoelectric conversion performance, and has certain antibacterial properties by photocatalytically generating ROSs. Therefore, taking ZnIn2S4 as a potential electron donor, copper ions are in-situ reduced by photocatalysis under visible light irradiation. By reasonable design and reducing recombination, the separation efficiency of photo-generated electrons (e - ) and holes (h + ) pairs can be improved.

[0004] Photocatalytic materials can achieve photocatalytic degradation of bacteria and other pollutants under the drive of visible light irradiation at a suitable band gap, and also have characteristics such as non-toxicity, stability and self-cleaning. However, in practical applications, there are problems such as material recovery and material loss. Membrane separation technology has become the main way to repair water environment due to its advantages such as environmental sustainability and energy conservation. Combining catalytic materials with membrane separation technology is one of the powerful means to solve this problem. In the scientific field of constructing multifunctional separation membranes, carbon nanotubes (CNTs) have received extensive attention due to their high specific surface area and the ability to be functionalized with polymer functional groups with specific properties. Therefore, combining CuNPs with good antibacterial properties, ZnIn2S4 with excellent photocatalytic properties and CNTs with a rich specific surface area to design a composite functional membrane material with high-efficiency sterilization and self-cleaning integrated may have good application prospects. Summary of the Invention

[0005] In order to overcome the disadvantages and deficiencies existing in the prior art, the purpose of the present invention is to provide a copper-based disinfectant composite functional membrane material, its preparation method and application. The specific technical solutions are as follows:

[0006] A preparation method of a copper-based disinfectant composite functional membrane material, comprising the following steps:

[0007] 1) Dissolve zinc salt, indium salt and sulfur source in water, adjust the pH of the mixed solution to acidic, transfer the mixed solution to a hydrothermal reaction kettle for reaction; after the reaction is completed, cool to room temperature, centrifuge, wash and dry the precipitate to obtain a zinc indium sulfide composite material;

[0008] 2) Dissolve copper salt in ultrapure water, ultrasonically disperse the prepared zinc indium sulfide composite material in water, and mix it with the prepared copper ion solution; under magnetic stirring and light irradiation, slowly inject a reducing solution to carry out a photo-deposition reaction for 5 - 180 min to obtain a copper-based disinfectant, denoted as Cu-ZnIn2S4;

[0009] 3) Heat CNTs in a mixed solution of H2SO4 / HNO3 at 40 - 80 °C for 2 - 6 h; after acidification, let the solution stand and remove the supernatant, add distilled water to the lower layer solution, and repeat removing the supernatant and adding distilled water until the supernatant is neutral after the solution stands and layers; filter and wash the obtained neutral solution, place the obtained black substance in a vacuum drying oven and dry it at 30 - 80 °C overnight to obtain acidified carbon nanotubes, denoted as CNTs-COOH. Carbon nanotubes are selected to construct a multifunctional separation membrane. On the one hand, it has a high specific surface area, which is beneficial to the effective adsorption of bacteria; on the other hand, it can be used as a secondary reaction platform to design functional membranes through chemical cross-linking, interfacial assembly and nanoparticle modification, thereby improving their capture ability for target bacteria;

[0010] 4) Ultrasonically disperse the acidified carbon nanotubes and polyethyleneimine, centrifuge the mixed solution, remove the supernatant, wash the precipitate with ultrapure water 3 - 5 times, and dry it to obtain PEI-functionalized CNTs, denoted as CNTs-PEI. After the acidified CNTs are functionalized with PEI, the surface of CNTs-PEI contains hydrophilic amino and carboxyl groups. The improvement of membrane hydrophilicity promotes the kinetic interaction between the membrane surface and microorganisms as well as the role in adsorption mass transfer, improves the adsorption and interception performance of bacteria, and further promotes the disinfection effect on bacteria;

[0011] 5) Prepare the CNTs-PEI obtained in step 4) into a CNTs-PEI dispersion; using the vacuum-assisted filtration method, filter the CNTs-PEI dispersion onto a hydrophilic polyvinylidene fluoride membrane under the condition of 0.9 bar to obtain a CNTs-PEI membrane. Adopt the vacuum-assisted filtration method to deposit carbon nanotubes on a hydrophilic polyvinylidene fluoride (PVDF) membrane to form a thin film;

[0012] 6) Prepare a Cu-ZnIn2S4 dispersion, and filter the Cu-ZnIn2S4 dispersion on the CNTs-PEI membrane prepared in step 5) to obtain a CNTs-PEI / Cu-ZnIn2S4 composite membrane.

[0013] Furthermore, the zinc salt in step 1) is zinc nitrate, zinc sulfate, zinc chloride, zinc phosphate, zinc acetate, zinc citrate, zinc isooctanoate or zinc glycinate, the indium salt is indium nitrate, indium sulfate, indium chloride, indium phosphate, indium acetate or indium citrate, and the sulfur source is thioacetamide, thiourea, ammonium sulfide or sodium thiosulfate. The molar ratio of the zinc salt, indium salt and sulfur source is 2-3:4-6:8-12.

[0014] Furthermore, the copper salt in step 2) is copper nitrate, copper phosphate, copper chloride, copper acetate or sodium copper ethylenediaminetetraacetate, and the mass ratio of copper to the sulfur-zinc-indium material is 0.1-2:10.

[0015] Furthermore, the reducing solution in step 2) is sodium borohydride, potassium borohydride, hydrazine, ethanol, ammonia water or sodium sulfite, the concentration of the reducing solution is 0.01-0.6 mol / L, the molar ratio to the copper salt is 3-15:1, and the injection rate of the reducing solution is 2-3 drops per second.

[0016] Furthermore, the volume ratio of 95-98% H2SO4 to 70% HNO3 during the acidification of carbon nanotubes in step 3) is 3:1.

[0017] Furthermore, the mass ratio of the acidified carbon nanotubes to polyethyleneimine in step 4) is 0.5-2:10; ultrasonically disperse the mixed solution for 0.5-1 h, centrifuge at 5000-10000 r / min for 3-10 min, remove the supernatant, wash the precipitate with ultrapure water 3-5 times, and dry it at 30-80 °C.

[0018] Furthermore, the ratio of the mass of CNTs-PEI filtered onto the polyvinylidene fluoride membrane in step 5) to the membrane area is 1-4:8, the mass unit is g, and the area unit is m 2 , and the concentration of the CNTs-PEI dispersion is 80-120 mg / L.

[0019] Further, in step 6), the ratio of the mass of Cu-ZIS filtered onto the CNTs-PEI membrane to the membrane area is 1-4:4, with the mass unit being g and the area unit being m 2 , and the concentration of the Cu-ZIS dispersion is 60-120 mg / L.

[0020] A copper-based disinfectant composite functional membrane material prepared by the above preparation method.

[0021] An application of the above copper-based disinfectant composite functional membrane material in the process of photocatalytic antibacterial. During the photocatalytic antibacterial process, the CNTs-PEI / CZIS composite membrane with good hydrophilicity can effectively promote its interaction with bacteria and achieve more effective bacterial disinfection, such as Escherichia coli, Pseudomonas aeruginosa, Staphylococcus aureus, and miscellaneous bacteria in actual water samples. The inactivation rate can be close to 100% in 2 h (bacterial concentration ≥ 10 6 CFU / mL); the CNTs-PEI / CZIS composite membrane has high stability, can be recycled, has self-cleaning and broad-spectrum applicability, and has good environmental purification potential. It is a composite functional membrane material with high-efficiency sterilization and self-cleaning in one.

[0022] The beneficial effects of the present invention are as follows:

[0023] 1) By using hydrophilic polymer functionalization and vacuum-assisted filtration method, a series of CNTs-PEI / CZIS composite membranes were designed and prepared. The acidified CNTs were functionalized with PEI, so that the surface of CNTs-PEI contains hydrophilic amino and carboxyl groups, which have a high affinity for water and can adsorb and intercept bacteria on the membrane surface; under the irradiation of visible light, the ROSs generated by ZIS can directly induce the oxidation of cell components, break the bacterial cell wall, and cause bacterial inactivation. The addition of Cu brings more active sites, which is beneficial to accelerating bacterial inactivation, generating more ROSs, and more reducing e - for the reduction of Cu and extending the service life of the material.

[0024] 2) The CNTs-PEI / CZIS composite membrane can achieve efficient disinfection of bacteria, and the antibacterial ability is close to 100% within 2 h (bacterial concentration ≥ 10 6 CFU / mL). Through cyclic experiments and antibacterial performance experiments on different bacteria, it is further shown that the composite membrane has good chemical adaptability, high stability, recyclability, self-cleaning and broad-spectrum applicability, and has good environmental purification potential, which can provide new methods and ideas for effectively treating wastewater containing harmful microorganisms. Description of the Drawings

[0025] Figure 1XRD patterns of the CNTs-PEI, CNTs-PEI / ZIS, and CNTs-PEI / CZIS-25 composite membranes prepared in Example 1;

[0026] Figure 2 EDS elemental distribution map of CZIS prepared in Example 1;

[0027] Figure 3 Comparison chart of the photocatalytic antibacterial effects of the CNTs-PEI, CNTs-PEI*, CNTs-PEI / ZIS, CNTs-PEI / CZIS-15, CNTs-PEI / CZIS-25, and CNTs-PEI / CZIS-30 composite membranes;

[0028] Figure 4 Comparison chart of the effects of the CNTs-PEI / CZIS-25 composite membrane of the present invention on catalyzing and killing Pseudomonas aeruginosa, Staphylococcus aureus, and natural water bacteria;

[0029] Figure 5 Cyclic bactericidal efficiency chart of the CNTs-PEI / CZIS-25 composite membrane of the present invention. Detailed implementation manners

[0030] The present invention will be further described below in conjunction with the examples and the accompanying drawings of the specification, but the protection scope of the present invention is not limited thereto.

[0031] Example 1 Preparation of the CNTs-PEI / CZIS composite functional membrane material

[0032] Preparation of the CNTs-PEI / CZIS composite functional membrane material:

[0033] 1) CNTs were heated in a mixed solution of 95 - 98% H2SO4 / 70% HNO3 with a volume ratio of 3:1 at 70 °C for 2 h; after acidification, the solution was allowed to stand to remove the supernatant, distilled water was added to the lower layer solution, and the supernatant was repeatedly removed and distilled water was added until the supernatant was neutral after the solution stood and stratified; the obtained neutral solution was filtered and washed to remove impurities; the black substance obtained by filtration was placed in a vacuum drying oven and dried at 40 °C overnight to obtain acidified carbon nanotubes, denoted as CNTs-COOH;

[0034] 2) 0.02 g of acidified carbon nanotubes (CNTs-COOH) and 0.2 g of polyethyleneimine (PEI) were dissolved in 200 mL of ultrapure water and ultrasonically dispersed for 1 h; the mixed solution was centrifuged at 8000 r / min for 10 min, the supernatant was removed, the precipitate was washed 3 times with ultrapure water, and dried at 30 °C to obtain PEI-functionalized CNTs, denoted as CNTs-PEI;

[0035] 3) Prepare a 100 mg / L CNTs-PEI dispersion; using the vacuum-assisted filtration method, filter 10 mL of the dispersion onto a polyvinylidene fluoride (PVDF) membrane with a membrane area of 40 cm 2 to obtain a CNTs-PEI membrane;

[0036] 4) Prepare a Cu-ZnIn2S4 dispersion (100 mg / L) for standby; filter different volumes of the Cu-ZIS dispersion (15 mL, 25 mL, and 30 mL) onto the 40 cm 2 CNTs-PEI membrane prepared in step 3); obtain a CNTs-PEI / Cu-ZnIn2S4 composite membrane, and label it with CNTs-PEI / CZIS-x, where x represents the volume of the Cu-ZnIn2S4 dispersion. Similarly, a CNTs-PEI / ZIS composite membrane (without Cu) was prepared according to the same preparation process and operating conditions of the CNTs-PEI / CZIS composite membrane. The concentration and volume of the ZIS dispersion were the same as those of CZIS-25.

[0037] Preparation of ZnIn2S4 material:

[0038] Dissolve 0.068 g of ZnCl2, 0.239 g of InCl2·4H2O, and 0.15 g of CH3CSNH2 in an appropriate amount of ultrapure water, mix well, adjust the pH of the mixed solution to 1.0 with 2 M HCl solution, and stir magnetically for 30 min to form a 40 mL mixed metal salt solution; transfer the mixed solution to a hydrothermal reaction kettle with a polytetrafluoroethylene inner liner; seal the hydrothermal reaction kettle and place it in an oven, and keep it at 160 °C for 16 h; after the reaction is completed, wait for the precipitate to cool to room temperature, and centrifuge and wash it several times with ultrapure water and absolute ethanol to obtain a dark yellow solid substance, and place it in a 60 °C vacuum oven for vacuum drying for 12 h to obtain the ZnIn2S4 material.

[0039] Preparation of Cu-ZnIn2S4 material:

[0040] 4.2 mg of CuCl2 was ultrasonically dissolved in 5 mL of ultrapure water to prepare a copper ion solution for standby; 14.3 mg of NaBH4 was ultrasonically dissolved in 5 mL of ultrapure water to prepare an aqueous solution of sodium borohydride for standby; 100 mg of the prepared ZnIn2S4 material was ultrasonically dispersed in 40 mL of water, mixed with the prepared copper ion solution, transferred to a quartz photoreactor after ultrasonic treatment, and the dissolved oxygen was removed by nitrogen bubbling. Under magnetic stirring and light irradiation, the aqueous solution of sodium borohydride was injected at a rate of 3 drops per second. After 60 min, the photodeposition reaction was completed, and the temperature was maintained at room temperature in a constant temperature water bath during the reaction. After the reaction, the residual salts were removed by centrifugal washing with ultrapure water and absolute ethanol, and dried in a vacuum oven at 60 °C for 12 hours to obtain the Cu-ZnIn2S4 material.

[0041] The XRD patterns of the CNTs-PEI, CNTs-PEI / ZIS, and CNTs-PEI / CZIS-25 composite membranes prepared in Example 1 are as follows Figure 1 shown. The prepared CNTs-PEI material has obvious standard diffraction peaks of carbon-based materials, corresponding to the (002) and (110) crystal planes of carbon materials. In the XRD patterns of the CNTs-PEI / ZIS and CNTs-PEI / CZIS-25 composite membranes, due to the low loading amount of Cu, its characteristic diffraction peaks are not obvious, and the characteristic diffraction peaks of ZIS can be clearly observed, corresponding to the (006), (102), (110), and (116) crystal planes of hexagonal ZIS (JCPDS No. 72-0773), indicating that CZIS and CNTs-PEI have been successfully compounded. The EDS elemental distribution of CZIS is as follows Figure 2 shown. The elements Zn, In, S, and Cu are evenly distributed, indicating that Cu is evenly distributed on ZIS.

[0042] Example 2: The CNTs-PEI / CZIS-25 composite functional membrane material is used for killing Escherichia coli

[0043] In the photocatalytic antibacterial experiment, the antibacterial properties of various composite membrane materials were evaluated by the disinfection effect on bacteria. The disinfection steps are as follows: Take 200 µL of Escherichia coli suspension and add it to a conical flask (sterilized at high temperature) containing 10 mL of sterile Tryptic Soy Broth (TSB) broth; transfer them to a shaker and culture at 37 °C and 100 rpm for 12 h; put the cut CNTs-PEI / CZIS-25 composite material membrane sample into a 24-well culture plate and add 0.1 mL of the bacterial suspension (10 6 CFU mL -1), and 1 mL of high-temperature sterilized PBS solution; during the photocatalysis process (xenon lamp, 420 < λ < 630 nm, 300 W), 0.1 mL of the suspension was taken every 1 h, and the bacteria-containing sample obtained by standard serial dilution was used; 0.1 mL of the diluted bacteria-containing sample was dropped onto the TSA medium, and evenly spread with an L-shaped spreading rod, and incubated at 37 °C in a bacterial incubator for 18 h, and the colonies on the agar plate were counted. From Figure 3 It can be seen that after 2 h, the inactivation rate of the CNTs-PEI / CZIS-25 composite membrane material disinfection system against Escherichia coli can be close to 100%. This excellent performance is on the one hand due to ZIS, which is reflected in that the CNTs-PEI / CZIS-25 composite membrane surface contains hydrophilic amino and carboxyl groups that can adsorb and intercept bacteria on the surface. Under visible light irradiation, the ROSs generated by ZIS, such as HO• and O2• - , can directly induce the oxidation of cell components, destroy the bacterial cell wall, and the active substances leak from the cell interior, resulting in bacterial inactivation. On the other hand, it comes from the excellent antibacterial performance of Cu itself and its "special properties". The addition of Cu not only brings more active sites, which is beneficial to accelerating the inactivation of bacteria, but also can inhibit e - / h + complex, generate more ROSs, and more e - is used for the reduction of Cu, extending the service life of the material.

[0044] Comparative Example 1 CNTs-PEI membrane material for disinfecting Escherichia coli

[0045] The CNTs-PEI membrane material used was from Example 1. Referring to the photocatalytic antibacterial process of Example 2, Escherichia coli was selected as the disinfection evaluation object. From Figure 3 It can be seen that after 2 h, the inactivation effect of the CNTs-PEI membrane material disinfection system on Escherichia coli is weak, and the inactivation rate is only 35%, indicating that under visible light irradiation, the acidified carbon nanotubes functionalized with PEI may cause mechanical damage to the cell wall or cell membrane of some bacteria.

[0046] Comparative Example 2 CNTs-PEI* membrane material for disinfecting Escherichia coli

[0047] The CNTs-PEI material used was from Example 1. Using the vacuum-assisted filtration method, 100 mg / L of CNTs-PEI in step 3) of Example 1 was filtered at 0.9 bar for 15 mL onto a polyvinylidene fluoride (PVDF) membrane with an effective area of 40 cm 2 to obtain the CNTs-PEI* membrane. Referring to the photocatalytic antibacterial process of Example 2, Escherichia coli was selected as the disinfection evaluation object. From Figure 3It can be seen that after 2 h, the inactivation rate of E. coli by the CNTs-PEI* membrane material was 38%, showing no significant difference from the sterilization effect of the CNTs-PEI membrane material. This indicates that in this elimination system, the addition amount of the CNTs-PEI dispersion has little effect on the bactericidal effect, and mechanical damage to bacteria may be the main sterilization method of the CNTs-PEI dispersion.

[0048] Comparative Example 3: Use of the CNTs-PEI / ZIS composite functional membrane material for killing and eliminating E. coli

[0049] The used CNTs-PEI / ZIS composite membrane material was from Example 1. Referring to the photocatalytic antibacterial process of Example 2, E. coli was selected as the object for killing and elimination evaluation. From Figure 3 It can be seen that after modification with ZIS, after 2 h, the inactivation rate of the CNTs-PEI / ZIS composite membrane material killing and elimination system for E. coli was close to 75%. This significant change was attributed to the visible light absorption ability of ZIS within the visible light spectrum range.

[0050] Comparative Example 4: Use of the CNTs-PEI / CZIS-15 and CNTs-PEI / CZIS-30 composite functional membrane materials for killing and eliminating E. coli

[0051] The used CNTs-PEI / CZIS-15 and CNTs-PEI / CZIS-30 composite membrane materials were from Example 1. Referring to the photocatalytic antibacterial process of Example 2, E. coli was selected as the object for killing and elimination evaluation. From Figure 3 It can be seen that after 2 h, the inactivation rate of the CNTs-PEI / CZIS-15 composite membrane material killing and elimination system for E. coli was close to 90%, and the inactivation rate of the CNTs-PEI / CZIS-30 composite membrane material killing and elimination system for E. coli was close to 100%. From the sterilization effects of the CNTs-PEI / CZIS-15, CNTs-PEI / CZIS-25, and CNTs-PEI / CZIS-30 composite membrane materials, it can be known that the CNTs-PEI / CZIS-15 composite membrane material failed to completely inactivate E. coli. Considering that the addition amount of the Cu-ZnIn2S4 dispersion was small, a small number of E. coli survived. The sterilization effects of the CNTs-PEI / CZIS-25 and CNTs-PEI / CZIS-30 composite membrane materials were almost the same, indicating that filtering 25 mL of the Cu-ZnIn2S4 dispersion on the CNTs-PEI membrane was sufficient to achieve the best sterilization effect.

[0052] Example 3: Use of the CNTs-PEI / CZIS-25 composite functional membrane material for killing and eliminating Pseudomonas aeruginosa

[0053] The used CNTs-PEI / CZIS-25 composite membrane material comes from Example 1. Referring to the photocatalytic antibacterial process of Example 2, Pseudomonas aeruginosa was selected as the object for disinfection and sterilization evaluation. From Figure 4 It can be seen that after 2 h, the inactivation rate of the CNTs-PEI / CZIS-25 composite membrane material disinfection and sterilization system against Pseudomonas aeruginosa can be close to 100%.

[0054] Example 4 Application of CNTs-PEI / CZIS-25 Composite Functional Membrane Material in Disinfection and Sterilization of Staphylococcus aureus

[0055] The used CNTs-PEI / CZIS-25 composite membrane material comes from Example 1. Referring to the photocatalytic antibacterial process of Example 2, Staphylococcus aureus was selected as the object for disinfection and sterilization evaluation. From Figure 4 It can be seen that after 2 h, the inactivation rate of the CNTs-PEI / CZIS-25 composite membrane material disinfection and sterilization system against Staphylococcus aureus is also close to 100%.

[0056] Example 5 Application of CNTs-PEI / CZIS-25 Composite Functional Membrane Material in Natural Water Sterilization

[0057] The used CNTs-PEI / CZIS-25 composite membrane material comes from Example 1. Referring to the photocatalytic antibacterial process of Example 2, natural water was selected as the object for disinfection and sterilization evaluation. From Figure 4 It can be seen that after 1 h, the inactivation rate of the CNTs-PEI / CZIS-25 composite membrane material disinfection and sterilization system against natural water bacteria is also close to 100%.

[0058] Example 6 Recycling Bactericidal Performance of CNTs-PEI / CZIS-25 Composite Functional Membrane Material

[0059] The used CNTs-PEI / CZIS-25 composite membrane material comes from Example 1. Referring to the photocatalytic antibacterial process of Example 2, Escherichia coli was selected as the object for disinfection and sterilization evaluation. To investigate the recycling performance of the CNTs-PEI / CZIS-25 composite membrane material, 5 recycling bactericidal experiments were carried out on it. After each experiment, the used composite membrane was recovered by washing alternately with alcohol / water and visible light irradiation (self-cleaning). The recycling sterilization effect of the CNTs-PEI / CZIS-25 composite membrane is as Figure 5 shown. It can be clearly observed that the bactericidal efficiency after recycling still remains at a relatively high level (after five cycles, the E. coli bactericidal efficiency still remains above 98%). This indicates that the prepared CNTs-PEI / CZIS-25 composite membrane has high stability and can be effectively reused. At the same time, it can be driven by visible light for disinfection and self-cleaning, and has good environmental purification potential.

Claims

1. A method for preparing a copper-based disinfectant composite functional membrane material, characterized in that: The following steps are involved: Dissolve zinc salt, indium salt and sulfur source in water, adjust the pH of the mixed solution to acidic, transfer the mixed solution to a hydrothermal reactor for reaction; after the reaction is completed, cool to room temperature, centrifuge, wash and dry the precipitate to obtain a sulfur-indium-zinc composite material; The copper salt is dissolved in ultrapure water, and the prepared sulfur-indium-zinc composite material is ultrasonically dispersed in the water and mixed with the prepared copper ion solution; under magnetic stirring and light irradiation, a reducing solution is injected to perform a photodeposition reaction for 5-180 min to obtain a copper-based disinfectant, which is recorded as Cu-ZnIn2S4; CNTs were heated in a H2SO4 / HNO3 mixed solution at 40-80°C for 2-6 h; after acidification, the solution was allowed to stand and the supernatant was removed, and distilled water was added to the lower solution. After the solution was allowed to stand and stratified, the supernatant was removed repeatedly and distilled water was added until the supernatant was neutral; the obtained neutral solution was filtered and washed, and the obtained black substance was placed in a vacuum drying oven at 30-80°C and dried overnight to obtain acidified carbon nanotubes, which were recorded as CNTs-COOH; The acidified carbon nanotubes and polyethyleneimine were ultrasonically dispersed, the mixed solution was centrifuged, the supernatant was removed, the precipitate was washed with ultrapure water for 3 to 5 times, and dried to obtain PEI-functionalized CNTs, which were recorded as CNTs-PEI; The CNTs-PEI obtained in step 4) is formulated into a CNTs-PEI dispersion; the dispersion is filtered onto a hydrophilic polyvinylidene fluoride membrane at 0.9 bar using a vacuum-assisted filtration method to obtain a CNTs-PEI membrane; preparing a Cu-ZnIn2S4 dispersion, filtering the Cu-ZnIn2S4 dispersion on the CNTs-PEI membrane prepared in step 5), and obtaining a CNTs-PEI / Cu-ZnIn2S4 composite membrane; Step 3) During the acidification of carbon nanotubes, the volume ratio of 95-98% H2SO4 to 70% HNO3 is 3:1; The ratio of the mass of Cu-ZIS filtered onto the CNTs-PEI membrane to the membrane area in step 6) is 1-4:4, with the mass unit being g and the area unit being m 2 , the concentration of Cu-ZIS dispersion is 60-120 mg / L; In step 4), the mass ratio of the acidified carbon nanotubes to polyethyleneimine is 0.5-2:10, and ultrasonic dispersion is performed for 0.5-1 h.

2. The method for preparing a copper-based disinfectant composite functional membrane material according to claim 1, characterized in that: The zinc salt in step 1) is zinc nitrate, zinc sulfate, zinc chloride, zinc phosphate, zinc acetate, zinc citrate, zinc isooctanoate or zinc glycinate, the indium salt is indium nitrate, indium sulfate, indium chloride, indium phosphate, indium acetate or indium citrate, the sulfur source is thioacetamide, thiourea, ammonium sulfide or sodium thiosulfate, and the molar ratio of the zinc salt, indium salt and sulfur source is 2-3:4-6:8-12.

3. The method for preparing a copper-based disinfectant composite functional membrane material according to claim 1, characterized in that: The copper salt in step 2) is copper nitrate, copper phosphate, copper chloride, copper acetate or sodium copper ethylenediaminetetraacetate, and the mass ratio of copper to the sulfur-indium-zinc composite material is 0.1-2:

10.

4. The method for preparing a copper-based disinfectant composite functional membrane material according to claim 1, characterized in that: The reducing solution in step 2) is sodium borohydride, potassium borohydride, hydrazine, ethanol, ammonia water or sodium sulfite, the concentration of the reducing solution is 0.01-0.6 mol / L, the molar ratio of the reducing solution to the copper salt is 3-15:1, and the injection speed of the reducing solution is 2-3 drops per second.

5. The method for preparing a copper-based disinfectant composite functional membrane material according to claim 1, characterized in that: In step 4), the mass ratio of the acidified carbon nanotubes to polyethyleneimine is 0.5-2:10; ultrasonic dispersion is performed for 0.5-1 h, the mixed solution is centrifuged at 5000-10000 r / min for 3-10 min, the supernatant is removed, the precipitate is washed with ultrapure water for 3-5 times, and dried at 30-80°C.

6. The method for preparing a copper-based disinfectant composite functional membrane material according to claim 1, characterized in that: The ratio of the mass of CNTs-PEI filtered onto the polyvinylidene fluoride membrane to the membrane area in step 5) is 1-4:8, with the mass unit being g and the area unit being m 2 , the concentration of CNTs-PEI dispersion is 80-120 mg / L.

7. A copper-based disinfectant composite functional membrane material prepared by the preparation method as described in any one of claims 1 to 6.

8. Use of the copper-based disinfectant composite functional membrane material as claimed in claim 7 in a photocatalytic antibacterial process.

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