Sunlight-driven synergistic antibacterial mask filter material and preparation method thereof

Abstract

The present invention relates to the technical field of mask filter core materials, and in particular to a mask filter core material based on sunlight-driven synergistic antibacterial and a preparation method thereof, comprising multifunctional antibacterial nanofibers loaded with nanoparticles, wherein the nanoparticles are ZIF-90 and MoO 3‑x Nanocomposite ZIF‑90@MoO formed by in situ growth method 3‑x The nanofiber is polylactic acid (PLA) fiber, and the nanocomposite material ZIF‑90@MoO 3‑x Multifunctional antibacterial nanofiber PLA@ZIF-90 / MoO was prepared by solution blowing method by mixing with polylactic acid (PLA) fiber. 3‑x The present invention adopts the above-mentioned sunlight-driven synergistic antibacterial mask filter material and preparation method. The prepared mask filter material can perform high-efficiency antibacterial under the synergistic effect of photocatalysis and photothermal reaction, and the mask filter material can achieve self-degradation after use, avoiding the problem of environmental pollution caused by incineration.

Description

Technical Field

[0001] The present invention relates to the technical field of mask filter core materials, and in particular to a mask filter core material based on sunlight-driven synergistic antibacterial properties and a preparation method thereof. Background Art

[0002] Respiratory infections are primarily transmitted through aerosols, characterized by rapid transmission, a wide range of susceptible populations, and high incidence rates. Wearing a protective mask can effectively block pathogens from entering the human body through the respiratory tract, thereby protecting people's health. For personal protection, the most commonly used are N95 respirators and medical surgical masks. These masks have a three-layer structure made of polypropylene (PP) fiber. The outermost layer is a waterproof layer that blocks droplets; the middle layer is a core filter layer that filters bacteria and droplets carried by airflow; and the innermost layer is a water-absorbing layer that primarily absorbs moisture produced by breathing. However, these masks have drawbacks: they lack antimicrobial activity, making them unsuitable for prolonged wear; they are not reusable; and after being worn for approximately four hours, their filtration efficiency deteriorates, resulting in a large number of discarded masks. These discarded masks may contain a large number of pathogens, increasing the risk of secondary disease transmission, thus increasing the demand for the safe disposal of used masks.

[0003] Traditional methods for reusing masks involve using disinfectants, ultraviolet radiation, and steam to kill bacteria. While these methods can kill microorganisms on the mask surface to a certain extent, they have drawbacks such as high energy consumption, reduced mask lifespan, increased bacterial resistance, and ozone pollution. Furthermore, most countries primarily use incineration as a means of disposing of discarded masks. Globally, over 200 million masks are consumed daily, and most are made from non-biodegradable polypropylene (PP) nonwovens. Incineration also generates large amounts of CO2 and toxic gases, increasing the greenhouse effect and causing serious environmental pollution. Due to the numerous shortcomings in the development and production of traditional masks, there is an urgent need to develop a new, multifunctional mask filter element that offers high antibacterial properties, filtering capabilities, and is reusable and biodegradable.

[0004] Photosensitizers (PSs) have become a key player in antimicrobial applications, leveraging their controllable light, virtually no resistance to drug resistance, and broad-spectrum bacterial activity to achieve highly effective antibacterial activity. PSs can perform photocatalytic antibacterial activities under illumination. When absorbing light of a certain wavelength, electrons or holes generated by electronic transitions interact with electron acceptors or electron donors adsorbed on the surface of the photocatalytic material, generating toxic reactive oxygen species (ROS). These ROS can rapidly react with a broad spectrum of microorganisms (including Gram-positive and Gram-negative bacteria, fungi, and capsid and lipid-encapsulated viruses), disrupting the cell walls and membranes of microbial cells, leading to leakage of cellular contents and subsequent cell death. Furthermore, photothermal agents (PTAs) have also demonstrated significant antibacterial activity in recent years. In PTA-based photothermal therapy (PTT), PTAs rapidly heat up upon irradiation with light of a certain wavelength, physically killing bacteria through elevated temperatures and preventing the emergence of drug-resistant bacteria. PTT offers a new therapeutic option for the clinical treatment of drug-resistant bacteria in today's rapidly resistant world. Nowadays, mankind is facing an increasingly severe energy crisis. Actively utilizing solar energy is often considered a promising strategy. When preparing mask filters, if sunlight-excited PSs and PTAs can be developed, the practicality and convenience of such materials will be greatly improved. Summary of the Invention

[0005] The purpose of the present invention is to provide a mask filter core material and a preparation method based on sunlight-driven synergistic antibacterial. The prepared mask filter core material can perform high-efficiency antibacterial under the synergistic action of photocatalysis and photothermal energy, and the mask filter core material can achieve self-degradation after use, avoiding the problem of environmental pollution caused by incineration.

[0006] To achieve the above objectives, the present invention provides a mask filter element based on sunlight-driven synergistic antibacterial, comprising multifunctional antibacterial nanofibers loaded with nanoparticles, wherein the nanoparticles are ZIF-90 and MoO 3-x Nanocomposite ZIF-90@MoO formed by in situ growth method 3-x The nanofiber is polylactic acid PLA fiber, and the nanocomposite material ZIF-90@MoO 3-x Multifunctional antibacterial nanofiber PLA@ZIF-90 / MoO was prepared by solution blowing method by mixing with polylactic acid (PLA) fiber. 3-x .

[0007] Preferably, the nanocomposite material ZIF-90@MoO 3-x Contains the construction of Z-type heterojunction.

[0008] A method for preparing a mask filter element material based on sunlight-driven synergistic antibacterial properties comprises the following steps:

[0009] S1 Preparation of MoO 3-x powder;

[0010] Molybdenum metal powder was dispersed in ethanol solution and stirred at room temperature, and then H2O2 was added to obtain a yellow solution. After heating and reaction, it was cooled to room temperature, washed, and vacuum dried to obtain MoO 3-x powder;

[0011] S2 will MoO 3-x Powder modification

[0012] Will MoO 3-x The powder was dispersed in methanol containing polyvinylpyrrolidone (PVP) and stirred evenly by magnetic stirring to obtain PVP-modified MoO 3-x ;

[0013] S3 preparation of ZIF-90 / MoO 3-x nanocomposites;

[0014] Dissolve imidazole-2-carboxaldehyde and PVP in solvent 1 and stir evenly to obtain solution A. Dissolve zinc nitrate hexahydrate in solvent 2 to obtain solution B. 3-x Disperse into solution B and stir for 24 h to obtain a mixed solution. Then, solution A was added to the above mixed solution, stirred at room temperature for 30 min, washed repeatedly with methanol, and vacuum dried to obtain ZIF-90 / MoO 3-x nanocomposites;

[0015] Preparation of PLA@ZIF-90 / MoO by S4 3-x Nanocomposite fibers

[0016] ZIF-90 / MoO 3-x The nanocomposite material was dissolved in 1,4-dioxane and ultrasonicated for 30 min, then polylactic acid (PLA) particles were added and magnetically stirred to obtain ZIF-90 / MoO 3-x The PLA spinning solution was dispersed evenly, and the obtained spinning solution was obtained by solution blowing to obtain PLA@ZIF-90 / MoO 3-x Nanocomposite fibers.

[0017] Preferably, the heating reaction in S1 is to transfer the solution into a polytetrafluoroethylene container, seal it in a stainless steel autoclave, and heat it at 160° C. and maintain it for 12 hours.

[0018] Preferably, the washing in S1 is performed by washing with ethanol and water three times respectively; and the vacuum drying is performed by vacuum drying at 60° C. overnight.

[0019] Preferably, after magnetic stirring for 13 hours in S2, the mixture is centrifuged, the supernatant is discarded, and the precipitated product is retained, and the precipitated product is washed three times with methanol.

[0020] Preferably, the solvent one in S3 is a mixed solvent of glycerol and water 1:1, and the solvent two is a mixed solvent of tert-butyl alcohol and water 1:1.

[0021] Preferably, the vacuum drying in S3 is drying at 60℃ for 12h.

[0022] The beneficial effects of the present application:

[0023] (1) The present application provides a mask filter material based on sunlight-driven synergistic antibacterial effect, which uses degradable polylactic acid (PLA) as the base material, and incorporates ZIF-90 / MoO 3-x nanocomposite material, PLA@ZIF-90 / MoO 3-x nanocomposite fiber is prepared by solution blowing technology. ZIF-90 / MoO 3-x The nanocomposite material reduces the recombination efficiency of electrons and holes through the construction of Z-type heterojunction, enhances the sunlight-driven ROS generation capacity of the nanomaterial, and improves the photocatalytic ability of the fiber membrane. MoO 3-x The fiber membrane has a certain photo-thermal effect, and the PLA@ZIF-90 / MoO 3-x nanocomposite fiber produces local heat, and the photocatalysis / photo-thermal synergistic effect makes the mask achieve high-efficiency antibacterial effect. 3-x

[0024] (2) The mask filter material based on sunlight-driven synergistic antibacterial effect provided by the present application has a dense fiber structure, so that the mask has high interception efficiency for PM 2.5 has high interception efficiency, and also ensures good air permeability of the mask.

[0025] (3) The used mask can utilize the photocatalytic performance of the nanomaterial to generate ROS to degrade antibiotics in medical wastewater and organic dyes in industrial wastewater, achieving the purpose of water purification and realizing the reuse of the discarded mask; using PLA as the mask filter base material can realize self-degradation of the discarded mask, avoiding the environmental pollution problem caused by incineration.

[0026] The technical solutions of the present application will be further described in detail below through the accompanying drawings and examples. BRIEF DESCRIPTION OF DRAWINGS

[0027] Figure 1 is a preparation method flowchart of the mask filter material of the present application;

[0028] Figure 2 is a characterization diagram of the ZIF-90 nanoparticles prepared in Example 2 of the present application;

[0029] Figure 3 is MoO 3-x ​Structural characterization of the powder;

[0030] Figure 4 MoO prepared in Example 3 of the present invention 3-x Powder performance characterization diagram;

[0031] Figure 5 The ZIF-90 / MoO prepared in Example 3 of the present invention 3-x Structural characterization diagram of nanocomposites;

[0032] Figure 6 The ZIF-90 / MoO prepared in Example 3 of the present invention 3-x Performance characterization diagram of nanocomposites;

[0033] Figure 7 The PLA fiber and PLA@ZIF-90 / MoO 3-x Physical picture of nanocomposite fiber;

[0034] Figure 8 The PLA@ZIF-90 / MoO 3-x Structural characterization of nanocomposite fibers;

[0035] Figure 9 The PLA@ZIF-90 / MoO 3-x Performance characterization diagram of nanocomposite fibers;

[0036] Figure 10 The PLA@ZIF-90 / MoO 3-x Schematic illustration of the antibacterial properties of nanocomposite fibers;

[0037] Figure 11 The PLA@ZIF-90 / MoO 3-x Schematic diagram of the photocatalytic degradation performance and zeta potential of nanocomposite fibers for TCHC;

[0038] Figure 12 The PLA@ZIF-90 / MoO 3-x Schematic illustration of the photocatalytic degradation performance of nanocomposite fibers toward organic dyes. DETAILED DESCRIPTION

[0039] The present invention is further described below with reference to the accompanying drawings and examples. Unless otherwise defined, technical or scientific terms used herein shall have the same meanings as those commonly understood by persons of ordinary skill in the art to which the present invention pertains. The above-mentioned features or features described in the specific examples of the present invention may be combined in any manner. These specific examples are intended only to illustrate the present invention and are not intended to limit the scope of the present invention.

[0040] Example 1

[0041] A mask filter material based on sunlight-driven synergistic antibacterial properties, comprising multifunctional antibacterial nanofibers loaded with nanoparticles, wherein the nanoparticles are ZIF-90 and MoO 3-x Nanocomposite ZIF-90@MoO formed by in situ growth method 3-x , nanocomposite material ZIF-90@MoO 3-x The nanofiber is polylactic acid (PLA) fiber, and the nanocomposite material ZIF-90@MoO 3-x Multifunctional antibacterial nanofiber PLA@ZIF-90 / MoO was prepared by solution blowing method by mixing with polylactic acid (PLA) fiber. 3-x .

[0042] Example 2

[0043] Figure 1 The figure is a flow chart of the preparation method of the mask filter material of the present invention. As shown in the figure, a preparation method of the mask filter material based on sunlight-driven synergistic antibacterial performance comprises the following steps:

[0044] S1 Preparation of ZIF-90 Nanoparticles

[0045] 0.48 g of imidazole-2-carboxaldehyde and 0.125 g of polyvinylpyrrolidone (PVP) were dissolved in a 1:1 mixed solvent of glycerol and water, and the above suspension was stirred at 70°C for 30 minutes to obtain a clear and transparent brown-yellow solution A; 0.7438 g of zinc nitrate hexahydrate was dissolved in a 1:1 mixed solvent of tert-butanol and water to obtain solution B; solution A was quickly poured into the stirred solution B to obtain a yellow-white suspension, which was stirred at room temperature for 30 minutes, then repeatedly washed with methanol three times, and dried in a vacuum at 60°C for 12 hours to obtain ZIF-90 nanoparticles.

[0046] Preparation of MoO by S2 3-x powder;

[0047] 2 mmol of molybdenum metal powder was dispersed in 24 mL of ethanol solution and stirred at room temperature, and then H2O2 (3 mL, 30%) was added to obtain a yellow solution. The solution was then transferred to a polytetrafluoroethylene container, sealed in a stainless steel autoclave, heated at 160 ° C and maintained for 12 h. After cooling to room temperature, it was washed with ethanol and water three times respectively, and dried in vacuum at 60 ° C overnight to obtain MoO 3-x powder.

[0048] S3 will MoO 3-x Powder modification

[0049] Will MoO 3-x(46 mg) was dispersed in methanol containing 93 mg of PVP and magnetically stirred for 13 h to prepare PVP-modified MoO 3-x The product was then separated by centrifugation, washed three times with methanol, and the supernatant was discarded to retain the precipitated product.

[0050] S4 Preparation of ZIF-90 / MoO 3-x nanocomposites;

[0051] ZIF-90 / MoO was prepared by in situ growth method. 3-x Composite material, 0.48g imidazole-2-carboxaldehyde and 0.125g PVP were dissolved in a 1:1 mixed solvent of glycerol and water, and the suspension was stirred at 70°C for 30min to prepare solution A, 0.7438g zinc nitrate hexahydrate was dissolved in a 1:1 mixed solvent of tert-butyl alcohol and water to obtain solution B, and then the PVP-modified MoO 3-x Disperse into solution B and stir for 24 h. Add solution A to the above solution, stir at room temperature for 30 min, wash repeatedly with methanol 3 times, and dry in vacuum at 60 °C for 12 h to obtain ZIF-90 / MoO 3-x Composite materials.

[0052] Preparation of PLA@ZIF-90 / MoO by S5 3-x (P@ZM) nanocomposite fibers

[0053] Weigh 0.27g ZIF-90 / MoO 3-x The nanomaterials were dissolved in 30 mL of 1,4-dioxane and ultrasonicated for 30 min. Then, 3 g of polylactic acid (PLA) particles were added and magnetically stirred for 12 h to prepare ZIF-90 / MoO 3-x A uniformly dispersed PLA spinning solution was prepared. Finally, the resulting spinning solution was used to produce P@ZM nanocomposite fibers using a solution jet spinning method. The specific parameters for solution jet spinning were: needle gauge: 30G, propulsion rate: 10mL / h, receiving roller speed: 300rpm, receiving distance: 30cm, and air pressure: 120MPa.

[0054] Example 3

[0055] Based on Example 1, the volume ratios of the oxidant (30%, H2O2) and the reducing agent (ethanol) in Example S2 are 2:1, 4:1, 6:1, 8:1, and 10:1, respectively, and the rest are the same as in Example 1.

[0056] Comparative Example 1

[0057] 3g of polylactic acid (PLA) pellets were dissolved in 30mL of 1,4-dioxane, ultrasonicated for 30 minutes, and magnetically stirred for 12 hours to obtain a uniformly dispersed PLA spinning solution. The resulting spinning solution was then used to produce PLA nanofibers using a solution jet spinning method. The specific parameters for solution jet spinning were: needle gauge: 30G, propulsion rate: 10mL / h, receiving roller speed: 300rpm, receiving distance: 30cm, and air pressure: 120MPa.

[0058] Comparative Example 2

[0059] Weigh 0.27g MoO 3-x The nanomaterials were dissolved in 30 mL of 1,4-dioxane and ultrasonicated for 30 min. Then, 3 g of polylactic acid (PLA) particles were added and magnetically stirred for 12 h to prepare MoO 3-x The PLA spinning solution was evenly dispersed. Finally, the obtained spinning solution was obtained by solution jet spinning to obtain PLA@MoO 3-x (P@M) nanocomposite fibers. The specific parameters for solution jet spinning are: needle gauge: 30G, propulsion rate: 10 mL / h, receiving roller speed: 300 rpm, receiving distance: 30 cm, and air pressure: 120 MPa.

[0060] Characterization experiments

[0061] Characterization of the ZIF-90 nanoparticles prepared in Example 2

[0062] The morphology of ZIF-90 nanoparticles was obtained by scanning electron microscopy (SEM), and its crystal structure was verified by X-ray powder diffractometer (XRD). Figure 2 is a characterization diagram of ZIF-90 nanoparticles prepared in Example 2 of the present invention, Figure 2 a in the figure is the SEM image of ZIF-90 nanoparticles. Figure 2 b in FIG is the XRD pattern of ZIF-90 nanoparticles; Figure 2 As shown in a in FIG, the obtained ZIF-90 has a rhombic dodecahedral structure and a particle size of about 400 nm. Figure 2 As shown in Figure 2(b), the XRD pattern of the obtained ZIF-90 corresponds to that of simulated ZIF-90, indicating that ZIF-90 was successfully prepared.

[0063] The MoO prepared in Example 2-3 3-x Characterization of the powder structure

[0064] MoO was obtained by scanning electron microscopy (SEM). 3-x The powder morphology was analyzed and its crystal structure was verified by X-ray powder diffractometer (XRD). Figure 3The MoO prepared in Example 2-3 of the present invention 3-x Structural characterization of the powder, Figure 3 a in the equation is MoO 3-x SEM images of powder materials, Figure 3 b in the equation is MoO 3-x The XRD pattern of the powder material is given by Figure 3 The a in MoO 3-x It is a sheet-like nanomaterial with a crystal size of about 800nm. Figure 3 As can be seen from b in Example 2 and Example 3, the MoO 3-x The XRD peaks of the nanosheets are consistent with those reported in the literature. 3-x The nanosheet crystal structure is consistent, confirming that MoO 3-x Successful synthesis of nanosheets.

[0065] And by Figure 3 As can be seen from the figure b, the samples synthesized under different ratios of oxidant and reducing agent prepared in Example 3 are all orthorhombic molybdenum trioxide phases. 3-x The three-dimensional structural framework of MoO2 was largely retained, which indicates that the reduction of ethanol did not destroy the original crystal structure. As the ratio of reducing agent decreased, the intensity of the characteristic peak of molybdenum trioxide was significantly weakened. When the ratio reached C2H5OH:H2O2=2:1, the characteristic peak disappeared. This may be due to the 3-x The orthorhombic phase has been transformed into amorphous MoO2.

[0066] The MoO prepared in Example 3 3-x Characterization of powder properties

[0067] The MoO prepared in Example 3 was evaluated by ultraviolet diffuse reflectance (UV-Vis-DRS). 3-x The photocatalytic performance of different products was tested by electrochemical impedance spectroscopy (ESI) in terms of light absorption capacity in the UV-visible region. Figure 4 MoO prepared in Example 3 of the present invention 3-x Powder performance characterization diagram, Figure 4 a in the equation is MoO 3-x UV-Vis-DRS diagram of powder, Figure 4 b in the equation is MoO 3-x ESI images of powders, such as Figure 4 As shown in cd, the ratio of oxidant to reducing agent is 3-x The photocatalytic activity of MoO was greatly affected by the reaction of C2H5OH:H2O2=8:1. 3-x Compared with the products under other conditions, the photocatalytic performance is better and it has stronger visible light absorption ability, while the electron and hole recombination efficiency is low.

[0068] The ZIF-90 / MoO prepared in Example 2 3-x Characterization of the structure of nanocomposites

[0069] Figure 5 The ZIF-90 / MoO prepared in Example 3 of the present invention 3-x Structural characterization of nanocomposites, Figure 5 a in ZIF-90 / MoO 3-x SEM images of nanocomposites. Figure 5 b in the figure is ZIF-90 / MoO 3-x Elemental mapping of nanocomposites; e.g. Figure 5 As shown in a, ZIF-90 nanoparticles are densely loaded on MoO 3-x On the nanosheet, the crystal size is about 900nm. Figure 5 As shown in b, it shows the presence of Mo, O, Zn, C and N elements, and ZIF-90 has a strong affinity with MoO 3-x Uniform distribution on the nanosheets.

[0070] Figure 5 c in ZIF-90 / MoO 3-x XRD spectrum of nanocomposite materials, Figure 5 d in ZIF-90 / MoO 3-x Fourier transform infrared spectrometer (FTIR) diagram of nanocomposites, such as Figure 5 As shown in Figure c, the characteristic peaks of the composite material are consistent with those of the single-component nanomaterial, confirming that ZIF-90 / MoO 3-x The successful preparation of nanocomposites. Figure 5 As shown in (d), compared with the individual components, the composite material has all the characteristic peaks of the single components, further indicating the successful preparation of the nanocomposite material.

[0071] The ZIF-90 / MoO prepared in Example 2 3-x Characterization of the properties of nanocomposites

[0072] The ultraviolet diffuse reflectance (UV-Vis-DRS) spectra of ZIF-90 / MoO 3-x The light absorption ability of the composite material was studied by photoluminescence (PL) spectroscopy to investigate the ZIF-90 / MoO 3-x The photogenerated charge separation ability of ZIF-90 and ZIF-90 was detected by electron spin resonance spectroscopy (ESR). 3-x The types of ROS generated by nanocomposites were analyzed, and the effects of ZIF-90 and MoO on the ROS generation were analyzed. 3-xThe band gap and valence band of ZIF-90 / MoO were tested to calculate the conduction band and obtain the 3-x Band structure of the composite material.

[0073] Figure 6 The ZIF-90 / MoO prepared in Example 3 of the present invention 3-x Performance characterization diagram of nanocomposites, Figure 6 a in ZIF-90 / MoO 3-x UV-Vis-DRS images of nanocomposites, Figure 6 b in the figure is ZIF-90 / MoO 3-x PL spectra of nanocomposites, Figure 6 c in ZIF-90 / MoO 3-x The generation of ·OH in nanocomposites under light and darkness, Figure 6 d in ZIF-90 / MoO 3-x Nanocomposites under light and darkness 2- The occurrence of Figure 6 e in ZIF-90 / MoO 3-x Energy band structure diagram of nanocomposites, Figure 6 f in ZIF-90 / MoO 3-x Schematic diagram of the temperature of nanocomposites changing with visible light power. Figure 6 As shown in a, ZIF-90 doped with MoO 3-x After that, the light absorption range is extended from the ultraviolet region to the visible light region, and the light utilization efficiency is improved. Figure 6 As shown in b, ZIF-90 / MoO 3-x The fluorescence intensity of the nanocomposite material is significantly lower than that of the ZIF-90 single material, indicating that the recombination efficiency of photogenerated electrons and holes is reduced, the photocatalytic ability is improved, and the heterojunction is successfully constructed.

[0074] like Figure 6 As shown in cd, ZIF-90 / MoO 3-x No ROS are produced in the dark, but superoxide anions (·O 2- ) and hydroxyl radicals (·OH), and the ROS intensity generated by the composite material is stronger than that of the single material, which further verifies the successful construction of the heterojunction and the improvement of the photocatalytic ability. Figure 6 As shown in e, ZIF-90, MoO 3-x The two can form a Z-type heterojunction, that is, the composite material can produce ROS. Figure 6 As shown in f, ZIF-90 / MoO 3-xThe photothermal properties of nanocomposites in aqueous solution show a certain dependence on visible light power. When the power reaches 1000W / m 2 The material temperature can reach 45°C.

[0075] The structure of the P@ZM nanocomposite fiber prepared in Example 2 was characterized

[0076] Figure 7 The PLA fiber and PLA@ZIF-90 / MoO 3-x Actual picture of nanocomposite fiber,7 Figure 7 As shown, PLA nanofibers are ZIF-90 / MoO 3-x Provides a supporting platform for ZIF-90 / MoO 3-x Evenly fixed on its surface, enhancing the photocatalytic and photothermal effects.

[0077] Figure 8 The PLA@ZIF-90 / MoO 3-x Structural characterization of nanocomposite fibers. Figure 8 a in the figure is the SEM image of PLA fiber. Figure 8 b in the figure is PLA@ZIF-90 / MoO 3-x SEM images of nanocomposite fibers. Figure 8 c in the figure is a schematic diagram of the contact angle of PLA fibers. Figure 8 d in the equation is PLA@ZIF-90 / MoO 3-x Schematic diagram of the contact angle of nanocomposite fibers. Figure 8 As shown in Figures a and b, the PLA nanofibers present a uniform, continuous, and smooth fiber structure. 3-x The ZIF-90 / MoO nanocomposite fibers can be clearly seen attached to the nanofiber surface. 3-x Nanoparticles. Figure 8 As shown in cd, the contact angle of PLA fiber membrane is about 122°, which has high hydrophobicity. 3-x Afterwards, its hydrophobicity increases to about 142°. The hydrophobicity of P@ZM nanofibers can ensure a certain antibacterial effect.

[0078] The properties of the P@ZM nanocomposite fibers prepared in Example 2 were characterized.

[0079] The light absorption capacity of the nanofiber membrane was evaluated by ultraviolet diffuse reflectance. Figure 9 The PLA@ZIF-90 / MoO 3-x Performance characterization diagram of nanocomposite fibers, Figure 9a in the figure is the UV-Vis-DRS of PLA@ZIF-90 / MoO 3-x UV-Vis-DRS of the nanocomposite fiber, Figure 9 b in the figure is the UV-Vis-DRS of PLA@ZIF-90 / MoO 3-x The schematic diagram of the photo-thermal performance evaluation of the nanocomposite fiber, from Figure 9 As can be seen from a in the figure, after 9% ZIF-90 / MoO 3-x was doped into PLA, the light absorption capacity was improved, and at the same time, as shown in b in the figure, the photo-thermal capacity was also improved, and about 50℃ can be reached in 5 min. Figure 9

[0080] Antibacterial performance test

[0081] The P@ZM nanocomposite fiber prepared in Example 2, the PLA nanofiber prepared in Comparative Example 1, and the P@M nanocomposite fiber prepared in Comparative Example 2 were subjected to antibacterial performance test.

[0082] The inactivation capacity of the PLA nanofiber, the P@M nanocomposite fiber, and the P@ZM nanocomposite fiber on E. coli was directly observed by using the plate coating method.

[0083] Figure 10 The figure is the antibacterial performance of the P@ZM nanocomposite fiber of the present application, Figure 10 a in the figure is the photo of the plate coating bacterial colony, Figure 10 b in the figure is the quantitative schematic diagram of the bacterial survival rate, as shown in Figure 10 a-b, the killing effect of the PLA nanofiber on the bacteria can be ignored under visible light irradiation or without visible light irradiation, and the P@M and the P@ZM also have almost no killing effect on the bacteria under dark conditions. Under the irradiation of 1000 W / m 2 After 30 min of visible light (one sun) irradiation, the P@M has about 35% antibacterial rate, which is because the photo-thermal effect of MoO 3-x can quickly heat up to high temperature to kill bacteria under light irradiation, and the P@ZM can achieve 99.99% antibacterial rate, which is because of the synergistic antibacterial effect of the photo-catalysis and the photo-thermal effect of the ZIF-90 / MoO3-x nanocomposite material.

[0084] The antibacterial performance of the PLA nanofiber, the P@M nanocomposite fiber, and the P@ZM nanocomposite fiber was detected by using the bacterial live / dead staining method.

[0085] In the live / dead bacterial activity kit, green nucleic acid dye (SYTO 9) and red fluorescent nucleic acid dye propidium iodide (PI) were used to stain the bacteria treated by each group of materials, wherein the live bacteria were dyed green and the dead bacteria were dyed red.

[0086] ​The experimental results showed that under dark and visible light conditions, E. coli treated with PLA nanofibers showed almost all green fluorescence. Under light conditions, the fluorescence images of the P@ZM group treated with PLA nanofibers showed almost all red fluorescence, indicating that the P@ZM composite nanofibers had a significant antibacterial effect. 2 , 30 min), the red signal observed in the P@ZM group was the strongest compared with other groups, which indicates that the synergistic antibacterial effect of photocatalysis and photothermal is better than that of a single antibacterial effect.

[0087] Recyclable properties of P@ZM fibers

[0088] Tetracycline hydrochloride (TCHC), a typical representative of antibiotics in medical wastewater, and rhodamine B (RhB), methyl blue (MB) and methyl orange (MO), typical representatives of organic dyes in industrial wastewater, were used to evaluate the photocatalytic degradation ability of P@ZM fibers on pollutants in medical wastewater and industrial wastewater.

[0089] The effect of the initial solution pH on the photocatalytic degradation of TCHC by composite fibers was investigated. Initial solutions with a pH range of 3-9 were selected and degraded using P@ZM fibers. The potential of the P@ZM fibers at different pH levels was also measured using a Malvern zeta potential meter.

[0090] Figure 11 The PLA@ZIF-90 / MoO 3-x Schematic diagram of the photocatalytic degradation performance and zeta potential of nanocomposite fibers for TCHC. Figure 11 a in the figure is a schematic diagram of photocatalytic degradation performance. Figure 11 b in the figure is a schematic diagram of zeta potential. Figure 11 As shown in Figures ab, when the initial solution is in a strong acidic state (pH = 3), the P@ZM fibers have little effect on TCHC degradation. This is likely due to the destruction of the nanomaterial structure under strong acidic conditions, which reduces its adsorption capacity. Furthermore, TCHC exists primarily in a cationic form, while the fiber itself has a positive potential, resulting in weak electrostatic adsorption between the two. As the pH increases from 5 to 9, the material assumes a negative potential, leading to increased electrostatic adsorption of TCHC by the P@ZM and higher degradation. This indicates that the P@ZM fibers have a wide pH range for the photocatalytic degradation of tetracycline hydrochloride.

[0091] Figure 12 The PLA@ZIF-90 / MoO 3-x Schematic diagram of the photocatalytic degradation performance of nanocomposite fibers for organic dyes. Figure 12It can be seen that the degradation rate of P@ZM fiber membrane for three organic dyes RhB, MB, and MO can reach more than 90%. Therefore, P@ZM fiber has great reuse value in the purification of medical wastewater and industrial wastewater.

[0092] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention rather than to limit the same. Although the present invention has been described in detail with reference to the preferred embodiments, those skilled in the art should understand that they can still modify or replace the technical solutions of the present invention with equivalents, and these modifications or equivalent replacements cannot cause the modified technical solutions to deviate from the spirit and scope of the technical solutions of the present invention.

Claims

1. A mask filter element material based on sunlight-driven synergistic antibacterial properties, characterized by: Multifunctional antibacterial nanofibers loaded with nanoparticles, wherein the nanoparticles are ZIF-90 and MoO 3-x Nanocomposite ZIF-90 / MoO formed by in situ growth method 3-x The nanofiber is polylactic acid PLA fiber, and the nanocomposite material ZIF-90 / MoO 3-x Multifunctional antibacterial nanofibers PLA@ZIF-90 / MoO were prepared by solution blowing method by mixing with polylactic acid PLA particles. 3-x Nanocomposite material ZIF-9 / MoO 3-x Contains the construction of Z-type heterojunction.

2. A method for preparing a mask filter element material based on sunlight-driven synergistic antibacterial according to claim 1, characterized in that: The following steps are involved: S1 Preparation of MoO 3-x powder Molybdenum metal powder was dispersed in ethanol solution and stirred at room temperature, and then H2O2 was added to obtain a yellow solution. After heating and reaction, it was cooled to room temperature, washed, and vacuum dried to obtain MoO 3-x powder; S2 will MoO 3-x Powder modification Will MoO 3-x The powder was dispersed in methanol containing polyvinylpyrrolidone (PVP) and stirred evenly by magnetic stirring to obtain PVP-modified MoO 3-x ; S3 preparation of ZIF-90 / MoO 3-x Nanocomposites Dissolve imidazole-2-carboxaldehyde and PVP in solvent 1 and stir evenly to obtain solution A. Dissolve zinc nitrate hexahydrate in solvent 2 to obtain solution B. 3-x The mixture was dispersed into solution B and stirred for 24 h to obtain a mixed solution. Solution A was then added to the mixed solution, stirred at room temperature for 30 min, washed repeatedly with methanol, and dried in vacuum to obtain ZIF-90 / MoO 3-x nanocomposites; Preparation of PLA@ZIF-90 / MoO by S4 3-x Nanocomposite fibers ZIF-90 / MoO 3-x The nanocomposite was dissolved in 1,4-dioxane and ultrasonicated for 30 min, then PLA particles were added and magnetically stirred to obtain ZIF-90 / MoO 3-x The PLA spinning solution was dispersed evenly, and the obtained spinning solution was obtained by solution blowing to obtain PLA@ZIF-90 / MoO 3-x Nanocomposite fibers.

3. The method for preparing a mask filter element material based on sunlight-driven synergistic antibacterial according to claim 2, characterized in that: The heating reaction in S1 was performed by transferring the solution into a polytetrafluoroethylene container, sealing it in a stainless steel autoclave, and heating it at 160 °C for 12 h.

4. The method for preparing a mask filter element material based on sunlight-driven synergistic antibacterial according to claim 2, characterized in that: The washing in S1 was performed by washing with ethanol and water three times respectively; the vacuum drying was performed by vacuum drying at 60° C. overnight.

5. The method for preparing a mask filter element material based on sunlight-driven synergistic antibacterial according to claim 2, characterized in that: After magnetic stirring for 13 h in S2, the mixture was centrifuged and the supernatant was discarded to retain the precipitated product, which was then washed three times with methanol.

6. The method for preparing a mask filter element material based on sunlight-driven synergistic antibacterial according to claim 2, characterized in that: In S3, solvent 1 is a mixed solvent of glycerol and water in a ratio of 1:1, and solvent 2 is a mixed solvent of tert-butanol and water in a ratio of 1:

1.

7. The method for preparing a mask filter element material based on sunlight-driven synergistic antibacterial according to claim 2, characterized in that: The vacuum drying in S3 was carried out at 60° C. for 12 h.

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