Process for the preparation of zinc-aluminum oxide powder by non-hydrolytic sol-gel and plasma flash

Abstract

The application belongs to the technical field of antibacterial materials, and provides a preparation method of zinc-aluminum oxide powder prepared by non-hydrolytic sol-gel and plasma flash, atomic uniform doping of aluminum in zinc-oxygen network is realized through anhydrous polycondensation reaction, a nano skeleton structure is maintained by supercritical drying, and oxygen vacancy concentration is precisely locked by millisecond high-temperature quenching, so that controllable preparation of the material and significant enhancement of infrared LSPR effect are realized. The zinc-aluminum oxide powder prepared by the application does not depend on an external light source, and only utilizes environmental blackbody radiation to realize efficient antibiosis in a completely light-free environment, and overcome the defect of light failure of traditional photocatalytic materials; the LSPR physical destruction and Zn 2+ The two mechanisms of ion chemical inactivation are synergistic, the sterilization efficiency is improved, the biological toxicity is reduced, and the environment is friendly.

Description

Technical Field

[0001] This invention belongs to the field of antibacterial materials technology, and particularly relates to a method for preparing zinc aluminum oxide powder by non-hydrolyzable sol-gel and plasma flash calcination. Background Technology

[0002] Existing mainstream antibacterial materials include traditional photo-excited inorganic antibacterial agents, ion-releasing inorganic antibacterial agents, organic antibacterial agents, and natural antibacterial agents, but most of them have limitations: Traditional photo-excited inorganic antibacterial agents include titanium dioxide and zinc oxide, but they rely on ultraviolet / visible light and are basically ineffective in light-free environments such as cold chain, warehouse, and dark room. Ion-releasing inorganic antibacterial agents include silver-based and copper-based agents. These antibacterial agents rely on the continuous release of metal ions to exert their effects, which poses problems such as cytotoxicity, environmental accumulation, and high cost. Organic antibacterial agents include quaternary ammonium salts and phenols, but they easily induce bacterial resistance; they have poor chemical stability, are not heat-resistant, and some pose environmental and health risks. Natural antibacterial agents include chitosan and essential oils, but they are expensive, have a narrow antibacterial spectrum, are easily oxidized and degraded, and require stringent storage conditions. Summary of the Invention

[0003] The purpose of this invention is to provide a method for preparing zinc aluminum oxide powder using non-hydrolyzable sol-gel and plasma flash calcination, thereby addressing the problems mentioned in the background art.

[0004] To achieve the above objectives, the present invention provides the following technical solution: On one hand, the present invention provides a method for preparing zinc aluminum oxide powder by non-hydrolyzable sol-gel and plasma flash calcination, comprising the following steps: S1. Preparation of non-hydrolyzable precursor sol: Dissolve anhydrous zinc chloride in anhydrous tetrahydrofuran, add acetylacetone, and stir to obtain zinc precursor solution; dissolve aluminum ethoxide in anhydrous tetrahydrofuran to obtain aluminum precursor solution; under vigorous stirring, slowly drop the aluminum precursor solution into the zinc precursor solution, and transfer the mixed solution to a high-pressure reactor with a polytetrafluoroethylene liner. S2. Controlled gelation and aging: The high-pressure reactor is placed in an oven, heated and kept at a constant temperature to induce a non-hydrolytic condensation reaction, forming a gel, which is then aged in a sealed environment. S3, Solvent replacement: After cooling, the gel is subjected to thorough solvent replacement with anhydrous tetrahydrofuran and anhydrous n-hexane in sequence; S4. Supercritical CO2 drying: The replaced gel is placed in a supercritical drying vessel and dried under supercritical CO2 conditions. Then the pressure is released to atmospheric pressure to obtain zinc aluminum oxide dry gel that maintains a high specific surface area nanoframework. S5. Radio frequency thermal plasma flash calcination: The zinc aluminum oxide dry gel is ground and sieved to obtain a precursor fine powder, which is then fed into a radio frequency inductively coupled plasma system for flash calcination to obtain a non-hydrolyzable sol-gel and plasma-calcined zinc aluminum oxide powder.

[0005] On the other hand, the present invention provides a non-hydrolyzable sol-gel and plasma flash zinc aluminum oxide powder, which is prepared by the above preparation method.

[0006] On the other hand, the present invention provides an application of non-hydrolyzable sol-gel and plasma flash-calcined zinc aluminum oxide powder in the preparation of antibacterial materials in dark environments.

[0007] Compared with the prior art, the specific beneficial effects of the present invention are as follows: This invention abandons the traditional high-temperature hot injection method and hydrolysis sol-gel method, and provides a non-hydrolysis sol-gel coupled supercritical drying and radio frequency thermal plasma flash calcination process. This process fundamentally achieves atomic-level homogeneous doping of aluminum in the zinc-oxygen network, and can precisely control the oxygen vacancy concentration through the plasma atmosphere to enhance the localized surface plasmon resonance (LSPR) effect of the material. The non-hydrolysis sol-gel path completely avoids component segregation caused by the difference in hydrolysis rates between zinc and aluminum during hydrolysis, achieving atomic-level homogeneous doping from the source. Supercritical CO2 drying eliminates the damage to the nanoframework caused by capillary forces during drying, retaining extremely high specific surface area and porosity, providing an ideal precursor for subsequent flash calcination. Plasma flash calcination instantly completes densification and crystallization, and the rapid cooling process "freezes" the high-temperature homogeneous solid solution, effectively suppressing second-phase precipitation and grain growth (average grain size controlled at 15-30). (nm); Through the in-situ pyrolysis and reduction of aluminum ethoxylate, combined with the precise control of the O2 ratio in the plasma atmosphere, the oxygen vacancy concentration in the product can be quantitatively adjusted, thereby allowing for customization of the LSPR absorption intensity of the material; it does not use high-boiling-point ligands such as oleic acid and octadecene required by traditional hot injection methods, and the post-processing is simple and environmentally friendly. The zinc-aluminum oxide powder prepared by this invention has the following characteristics: Overcoming light limitations, synergistic effects, and safety with low toxicity: It achieves highly efficient antibacterial activity in completely dark environments by utilizing only ambient blackbody radiation, without relying on external light sources, thus overcoming the shortcomings of traditional photocatalytic materials that fail without light; LSPR physical destruction and Zn 2+ The synergistic effect of iontophoresis and chemical inactivation enhances bactericidal efficiency, reduces biotoxicity, and is environmentally friendly; its antiviral and antibacterial mechanisms are as follows: Figure 1As shown, in a dark environment, zinc aluminum oxide powder first absorbs blackbody radiation from the environment and excites the LSPR effect. The localized enhanced electromagnetic field generated by this effect can not only directly physically destroy the bacterial cell membrane, but also significantly synergize and enhance the chemical antibacterial effect of the trace amounts of zinc and aluminum ions slowly released by the material itself. This novel mechanism of "infrared physical synergistic ion chemistry" is different from the traditional single ion dissolution antibacterial or photocatalytic antibacterial. Powder form facilitates application: It can be easily processed into coatings, films, composite materials, etc. through spraying, dipping, blending, etc., solving the problems of uneven dispersion and poor adhesion of liquid antibacterial agents on solid surfaces; Uniform doping and batch stability: The non-hydrolytic sol-gel combined plasma flash calcination process achieves atomic-level uniform substitutional doping of aluminum at the molecular level, avoiding component segregation and significantly improving product consistency and repeatability. Customizable performance: By adjusting the aluminum doping ratio, plasma oxygen partial pressure and flash burning parameters, the grain size, LSPR absorption peak position and intensity can be independently controlled to meet the differentiated antibacterial needs of different scenarios. Attached Figure Description

[0008] Figure 1 This is a schematic diagram illustrating the mechanism of the zinc aluminum oxide powder's antiviral and antibacterial effects provided in an embodiment of the present invention. Figure 2 A flowchart illustrating the preparation of non-hydrolyzable sol-gel and plasma flash zinc aluminum oxide powder provided in this embodiment of the invention; Figure 3 The images are scanning electron microscope (SEM) images of four sample powders provided in the embodiments of the present invention. A is zinc oxide powder, and B and D are zinc aluminum oxide powders with Zn / Al molar ratios of 1:0.05, 1:0.15, and 1:0.25, respectively. Figure 4 The following are the absorption spectra of four sample powders in the infrared region provided in the embodiments of the present invention; Figure 5 The diagram shows the anti-Escherichia coli effect provided in the embodiment of the present invention. A represents zinc oxide powder, and B represents three zinc aluminum oxide powders with different doping ratios. Figure 6 The images shown are SEM images of Escherichia coli provided in the embodiments of the present invention. A is a SEM image of normal Escherichia coli, and B is a SEM image of Escherichia coli whose cell membranes have been damaged by zinc aluminum oxide powder. Figure 7 The ion release test results provided in the embodiments of the present invention; Figure 8 The antiviral effect diagram provided in the embodiment of the present invention; Figure 9The images shown are transmission electron microscopy (TEM) images of the SARS-CoV-2 virus provided in the embodiments of the present invention. A is a TEM image of a normal SARS-CoV-2 virus, and B is a TEM image of a virus destroyed by zinc aluminum oxide powder. Detailed Implementation

[0009] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the invention.

[0010] The specific implementation of the present invention will be described in detail below with reference to specific embodiments.

[0011] Example 1: A non-hydrolyzable sol-gel and plasma flash calcination zinc aluminum oxide powder, the preparation method of which is as follows: Figure 2 As shown, the specific steps include: S1. Preparation of non-hydrolyzable precursor sol (operated entirely in an anhydrous and oxygen-free glove box): Dissolve 13.63 g of anhydrous zinc chloride (ZnCl2) in 250 mL of anhydrous tetrahydrofuran (THF), add 4.5 mL of acetylacetone (Hacac) as a reaction rate stabilizer, and stir for 2 hours to obtain a zinc precursor solution; Weigh aluminum ethoxide (Al(OEt)3) at Zn / Al molar ratios of 1:0.00, 1:0.05, 1:0.15, and 1:0.25 respectively, dissolve in 120 mL of anhydrous THF under slight heating, and obtain an aluminum precursor solution after cooling; Under vigorous stirring at 25 °C, the aluminum precursor solution is slowly dripped into the zinc precursor solution through a constant pressure dropping funnel for at least 60 minutes to ensure uniform polycondensation reaction. The mixed solution is then transferred to a high-pressure reactor with a polytetrafluoroethylene liner, sealed, and removed from the glove box. S2. Controlled gelation and aging: The high-pressure reactor was placed in an oven and heated to 100 ℃ at a rate of 0.5 ℃ / min and held for 36 hours. During this process, ZnCl2 and Al(OEt)3 underwent a non-hydrolytic condensation reaction to form a Zn-O-Al bonded network. The byproduct chloroethane escaped. After the gel was formed, it was aged in situ at 100 ℃ for 48 hours to strengthen the inorganic network framework. S3, Solvent replacement: After cooling, the gel is immersed in excess anhydrous THF and fresh THF is replaced every 12 hours for a total of 6 times to remove unreacted monomers and byproducts. Then, anhydrous n-hexane is used for solvent replacement, which is replaced every 8 hours for a total of 4 times, so that the liquid in the gel pores is completely replaced with n-hexane that is compatible with supercritical CO2. S4. Supercritical CO2 drying: The displaced gel was quickly transferred into a supercritical drying vessel, sealed, and repeatedly rinsed and soaked with liquid CO2 (10℃, 6 MPa) to fully displace the n-hexane in the gel. The temperature was then raised to 40℃ and the pressure was increased to 10 MPa to enter the supercritical CO2 state. The temperature and pressure were maintained for 2 hours. Then, the pressure was released to atmospheric pressure at 40℃ at a rate of 0.08 MPa / min. After that, it was purged with dry N2, cooled, and taken out to obtain zinc aluminum oxide dry gel with a high specific surface area nanoframework. S5. Radio Frequency Thermal Plasma Flash Calcination: Zinc-aluminum oxide dry gel was lightly ground and sieved in a glove box to obtain a fine precursor powder. The radio frequency inductively coupled plasma (RF-ICP) system was started, with the center gas being an Ar / O2 mixture (Ar 15 slm, O2 3 slm) and the sheath gas being an Ar / O2 mixture (Ar 40 slm, O2 5 slm). The operating power was 25 kW. The dry gel powder was injected into the high-temperature-rapid cooling interface region of the plasma tail flame along with the carrier gas (Ar, 3 slm) at a rate of 1.5 g / min. The powder remained at approximately 5000 K for 10-50 milliseconds, instantly completing the organic matter removal, crystallization, and Al substitution doping activation processes. Subsequently, it was cooled at an extremely high rate (10... 5 -10 6 The product was quenched at K / s and collected by a cyclone separator and an electrostatic precipitator. The adsorbed water was removed by vacuum drying at 150 °C for 6 hours to obtain zinc aluminum oxide powder sample (when the Zn / Al molar ratio is 1:0.00, zinc oxide powder sample is obtained).

[0012] Performance Analysis: 1. The zinc oxide powder sample prepared above and three groups of zinc aluminum oxide powder samples with different doping ratios were analyzed, and the scanning electron microscope (SEM) images are shown below. Figure 3 As shown (scale bar 50 nm), it can be seen that when the molar ratio of zinc to aluminum increases from 1:0.00 to 1:0.05, the morphology of the sample gradually changes from an irregular sphere to a hexagonal pyramid, and the content of hexagonal pyramid-shaped nanoparticles also increases continuously. When the molar ratio reaches 1:0.25, most of the synthesized zinc-aluminum-oxygen nanoparticles are hexagonal pyramid-shaped, and the resulting lattice fringes are more regular.

[0013] 2. Test the infrared spectrum of the sample to obtain the absorption spectrum in the infrared region, as shown below. Figure 4 As shown in the figure (where 1:0.00, 1:0.05, 1:0.15, and 1:0.25 represent the Zn / Al molar ratios), it can be seen that when the zinc to aluminum molar ratio is 1:0.00, the sample shows no significant absorption in the infrared region, while when the zinc to aluminum molar ratio is 1:0.05, it shows significant absorption at 1500 cm⁻¹. -1There is obvious absorption in the vicinity, and zinc aluminum oxide powders of other molar ratios also have obvious infrared absorption, indicating that the infrared spectrum also supports the LSPR mechanism.

[0014] 3. Antibacterial performance test (under light-protected conditions): The testing process includes the following steps: S1. Preparation of beef extract peptone solid culture medium: Weigh 3 g of beef extract, 10 g of peptone, 5 g of NaCl, and 15-20 g of agar. Make up to 1000 mL with deionized water and adjust the pH to 7.0-7.2. Seal the conical flask and place it in an autoclave. Sterilize at 121 °C for 20 min. Open the flask in a clean bench and pour the plates. After pouring, set aside to solidify. After solidification, invert the plates for later use. Preparation of S2 and LB liquid culture media: Weigh 10 g of peptone, 5 g of yeast powder, 10 g of NaCl and 2 g of glucose, make up to 1000 mL with deionized water, adjust the pH to 7.4, sterilize at 121 ℃ for 20 min, cool to room temperature and set aside. S3. Weigh 40 mg of the four sample powders prepared in Example 1 and press them into antibacterial tablets with a diameter of 6 mm and uniform thickness. S4. Bacterial culture (Escherichia coli (ATCC25922) Generation 2, purchased from Beijing TransGen Biotech Co., Ltd.): Measure 150 mL of LB liquid culture base into a 250 mL Erlenmeyer flask. Accurately pipette 1.5 mL of E. coli culture medium that has been cultured for 18 hours into the Erlenmeyer flask using a 5 mL sterile pipette. Shake to mix thoroughly. Place the inoculated Erlenmeyer flask on a shaker and incubate at 37 ℃. Take samples every two hours to determine the concentration. Once the bacterial concentration reaches the required concentration for the experiment, it can be used for subsequent experiments.

[0015] S5. Antibacterial zone test under light-protected conditions: On a sterile laminar flow hood, 100 μL of a concentration of 1.5 × 10⁻⁶ μL was taken. 6 The bacterial suspension of CFU / mL was evenly spread on the surface of solid agar medium. After even spreading, the antibacterial tablets were placed on the surface of the medium covered with bacterial suspension. The tablets were incubated at 37 ℃ in the dark for 24 h and then photographed. The diameter of the inhibition zone was measured with a ruler to compare the antibacterial performance of the materials under different doping ratios. Using pure zinc oxide powder tablets as a control, the results are as follows: Figure 5 As shown in the figure (where 1:0.00, 1:0.05, 1:0.15, and 1:0.25 represent the Zn / Al molar ratios), the scanning electron microscope image of E. coli being destroyed by zinc aluminum oxide powder is shown below. Figure 6 As shown (scale bar 1μm); according to Figure 5It can be seen that aluminum-doped zinc oxide powder has a better antibacterial zone effect than zinc oxide powder, indicating that aluminum doping is beneficial to improving the antibacterial effect of the material. according to Figure 6 It can be seen that aluminum-doped zinc oxide nanoparticles have a significant destructive effect on the cell membrane of Escherichia coli, further demonstrating that zinc-aluminum oxide powder has an antibacterial effect, and that the antibacterial mechanism is to destroy the cell membrane of Escherichia coli, leading to the death of Escherichia coli.

[0016] 4. Ion release test: The ion content released by the zinc-aluminum oxide powder (zinc to aluminum molar ratio of 1:0.25), which exhibited the best antibacterial effect, in the inhibition zone was tested using inductively coupled plasma mass spectrometry (ICP-MS). After coating *E. coli*, paper discs were first placed on the paper, and then 10 μL of different concentrations of solutions (AlCl3: 31.16 mg / mL, ZnCl2: 14.09 mg / mL, AlCl3 + ZnCl2: 31.16 mg / mL + 14.09 mg / mL) were dropped onto the filter paper and incubated statically to mimic the antibacterial effect of ion diffusion. The results are as follows: Figure 7 ; according to Figure 7 It can be seen that there is no significant difference between the antibacterial zone generated by the release of pure zinc ions and the antibacterial zone generated by the release of ions after the addition of aluminum, indicating that the enhanced antibacterial effect of the prepared zinc-aluminum oxide powder is not generated by ion release.

[0017] 5. Antiviral performance test: Five groups were set up: three groups with different proportions of zinc-aluminum-oxygen powder and a pure zinc oxide control group, which were mixed with SARS-CoV-2 virus suspension (Beyotime Biotechnology Co., Ltd.). A blank control group (only SARS-CoV-2 virus cultured) was also set up. Each sample was measured in triplicate. The samples of each group were transferred to opaque centrifuge tubes (wrapped in aluminum foil throughout) and incubated in a dark chamber at 37°C for 30 min, 120 min and overnight (16 h). After each time point, the samples were immediately taken under red light illumination, centrifuged at 12000 r / min and 4 °C for 10 min, and the supernatant was taken for 10-fold serial dilution. The diluted solution was then inoculated into host cells in the logarithmic growth phase (the plate density was pre-calibrated to 1×10⁻⁶). 5 Cells / well), covered with medium containing 2% low-melting-point agarose, and incubated in the dark for 30 and 120 minutes. The number of plaques was counted after each incubation, and the virus recovery rate (i.e., "actual sample titer ÷ initial virus titer × 100%)" was calculated. Results are as follows: Figure 8 As shown in the figure (where 1:0.00, 1:0.05, 1:0.15, and 1:0.25 represent the Zn / Al molar ratios), the transmission electron microscope (TEM) images of the virus being destroyed by zinc aluminum oxide powder are as follows. Figure 9 As shown (scale bar 50 nm); according to Figure 8 It can be seen that the pure zinc oxide control group has a certain antiviral effect compared with the blank control group, but the effect is not obvious. In contrast, the zinc aluminum oxide powder (zinc to aluminum molar ratio of 1:0.25) has a significant antiviral effect compared with the blank control group, and the antibacterial effect is more obvious with time. This indicates that the zinc aluminum oxide powder provided in the embodiments of the present invention has a good and long-lasting antiviral effect. according to Figure 9 It can be seen that the structural integrity of the virus with zinc aluminum oxide powder added was significantly disrupted, indicating that the zinc aluminum oxide powder provided in this embodiment of the invention has an antiviral effect.

[0018] Comprehensive Appendix Figure 3-9 The results show that as the aluminum doping ratio increases from 0 to 0.25, the morphology of the zinc-aluminum oxide powder gradually changes from an irregular spherical shape to a hexagonal pyramidal shape, and the lattice fringes become more regular. Simultaneously, the infrared absorption is significantly enhanced, indicating that aluminum doping induces a localized surface plasmon resonance effect. Regarding antibacterial performance against *E. coli*, the aluminum-doped sample exhibits a more pronounced inhibition zone compared to the undoped sample, and the sample with an aluminum doping ratio of 0.25 can significantly disrupt the *E. coli* cell membrane. Ion release testing shows no significant difference in the inhibition zones produced by pure zinc ions and aluminum-containing ions, and the antibacterial effect is very weak, confirming that the enhanced antibacterial effect does not originate from ion release. In terms of antiviral performance, the sample with an aluminum doping ratio of 0.25 can significantly reduce the SARS-CoV-2 virus recovery rate compared to the blank control group, and the effect increases with time. Transmission electron microscopy further confirms that the powder can directly disrupt the structural integrity of the virus. The zinc-aluminum oxide powder prepared in this embodiment of the invention exhibits good antiviral performance at 24°C. After h, all samples showed obvious transparent inhibition zones with significantly larger diameters than the pure zinc oxide group. The sample with a doping ratio of 1:0.25 exhibited the best antibacterial effect. This proves that in a completely dark environment, the material provided by the embodiments of the present invention has a long-lasting and efficient synergistic antibacterial ability, while the pure zinc oxide group has a weak antibacterial effect due to the lack of a strong LSPR synergistic effect.

[0019] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A method for preparing zinc aluminum oxide powder by non-hydrolyzable sol-gel and plasma flash calcination, characterized in that, Includes the following steps: S1. Preparation of non-hydrolyzable precursor sol: Dissolve anhydrous zinc chloride in anhydrous tetrahydrofuran, add acetylacetone, and stir to obtain zinc precursor solution; dissolve aluminum ethoxide in anhydrous tetrahydrofuran to obtain aluminum precursor solution; under vigorous stirring, slowly drop the aluminum precursor solution into the zinc precursor solution, and transfer the mixed solution to a high-pressure reactor with a polytetrafluoroethylene liner. S2. Controlled gelation and aging: The high-pressure reactor is placed in an oven, heated and kept at a constant temperature to induce a non-hydrolytic condensation reaction, forming a gel, which is then aged in a sealed environment. S3, Solvent replacement: After cooling, the gel is subjected to thorough solvent replacement with anhydrous tetrahydrofuran and anhydrous n-hexane in sequence; S4. Supercritical CO2 drying: The replaced gel is placed in a supercritical drying vessel and dried under supercritical CO2 conditions. Then the pressure is released to atmospheric pressure to obtain zinc aluminum oxide dry gel that maintains a high specific surface area nanoframework. S5. Radio frequency thermal plasma flash calcination: The zinc aluminum oxide dry gel is ground and sieved to obtain a precursor fine powder, which is then fed into a radio frequency inductively coupled plasma system for flash calcination to obtain a non-hydrolyzable sol-gel and plasma-calcined zinc aluminum oxide powder.

2. The method for preparing zinc aluminum oxide powder by non-hydrolyzable sol-gel and plasma flash calcination according to claim 1, characterized in that, In S1, the molar ratio of acetylacetone to zinc is 0.4-0.5:1; The molar ratio of zinc to aluminum is 1:0.05-0.

25.

3. The method for preparing zinc aluminum oxide powder by non-hydrolyzable sol-gel and plasma flash calcination according to claim 1, characterized in that, In S2, the specific process of heating and holding the temperature is as follows: the temperature is increased to 100 ℃ at a rate of 0.5 ℃ / min and held for 36 hours; The conditions for sealed aging are: sealed aging at 100 ℃ in situ for 48 hours.

4. The method for preparing zinc aluminum oxide powder by non-hydrolyzable sol-gel and plasma flash calcination according to claim 1, characterized in that, In S3, the process of fully replacing the gel with anhydrous tetrahydrofuran and anhydrous n-hexane in sequence is as follows: the gel is soaked in excess anhydrous tetrahydrofuran, and fresh anhydrous tetrahydrofuran is replaced every 12 hours for a total of 6 times; then anhydrous n-hexane is used for solvent replacement, and fresh anhydrous n-hexane is replaced every 8 hours for a total of 4 times.

5. The method for preparing zinc aluminum oxide powder by non-hydrolyzable sol-gel and plasma flash calcination according to claim 1, characterized in that, In S4, the drying process under supercritical CO2 conditions is as follows: the temperature is increased to 40 ℃ and the pressure is increased to 10 MPa to enter the supercritical state of CO2, and the temperature and pressure are maintained for 2 hours. The process of depressurizing to atmospheric pressure is as follows: depressurize slowly to atmospheric pressure at a rate of 0.08 MPa / min.

6. The method for preparing zinc aluminum oxide powder by non-hydrolyzable sol-gel and plasma flash calcination according to claim 1, characterized in that, In S5, the parameters of the radio frequency inductively coupled plasma system are: center gas Ar 15 slm, O2 3 slm; sheath gas: Ar 40 slm, O2 5 slm; power 25 kW.

7. A non-hydrolyzable sol-gel and plasma flash calcination zinc aluminum oxide powder, characterized in that, It is prepared using the preparation method described in any one of claims 1-6.

8. The application of the non-hydrolyzable sol-gel and plasma-flamed zinc aluminum oxide powder as described in claim 7 in the preparation of dark-environment antibacterial materials.

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