Synthesis method of high catalytic and antibacterial activity nano-zno multi-level structure material

Abstract

The application discloses a method for synthesizing high-catalysis and high-antibacterial-activity nano ZnO multi-level structure material, and belongs to the field of preparation of nano inorganic materials. The application provides a new method for preparing nano ZnO multi-level structure material with different morphologies in a one-step method by using ethylene glycol and an organic solvent as mixed solvents at normal pressure and in a low temperature range, and high-activity bowl-shaped multi-level structure of nano ZnO self-assembled is obtained in a simple system for the first time, without additional additives or strong alkali, so that the convenient, controllable and green synthesis of high-activity nano ZnO multi-level structure is realized. The prepared nano ZnO multi-level structure material has the performance of photocatalytic degradation of organic dyes and excellent antibacterial performance.

Description

TECHNICAL FIELD

[0001] The present application belongs to the field of preparation of nano-inorganic materials, and particularly relates to a synthesis method of nano ZnO multi-level structure material with high catalytic and antibacterial activity. BACKGROUND

[0002] Nano ZnO material has received extensive attention due to its unique properties and more extensive potential applications resulting from size effect, different morphologies and porosity, which are obviously different from ordinary size ZnO. So far, various nano ZnO with different morphologies (such as nanowires, nanobands, nanocombs, nano springs, tetragonal nanostructures, nanotubes, nanonails and nanohelices, etc.) have been synthesized in existing research work and patents. Due to this diversity of ZnO morphology size, it can be suitable for multifunctional applications in electronics, photonics and even bioelectronics technology, especially in ultraviolet light shielding, photocatalysis, antibiosis, gas and biological sensing, solar dye cells, biological medicine, etc. There have been extensive related research and applications. However, the size effect of nano materials brings high activity, but also causes agglomeration, nano toxicity, etc. due to the change of use conditions, thereby limiting its application. The ZnO multi-level structure formed by nano substructure assembly has a large specific surface area and high porosity, which can retain the activity of nano materials, and has better biocompatibility, is not easy to agglomerate and is easy to separate, thereby having an irreplaceable advantage over other morphology materials in the above applications. The synthesis method expansion and the control of crystal growth parameters in the synthesis process are the key to explore and develop new morphology structure and application function of nano ZnO material.

[0003] At present, the wet chemical method is more widely used in the synthesis of nano ZnO multi-level structure due to its synthesis process being easy to control, synthesis conditions being relatively mild, cost being relatively low, etc. Mainly includes high-pressure solvothermal, sol-gel, microwave-assisted method, etc. For example, the flower-like ZnO multi-level structure (the overall structure size is about 1.5 μm) obtained by high-pressure hydrothermal reactor at 120 ℃ for 24 h has better photocatalytic degradation efficiency of methylene blue [1] . The ZnO double-layer microsphere multi-level structure can be obtained by co-precipitation method, and then sintered at high temperature, which has good selectivity and sensitivity (detection limit is as low as 1 PPM) to ethanol as a gas sensing material [2] . The flower-like ZnO multi-level structure obtained by nano ZnO prepared by cetyltrimethylammonium bromide assisted high-pressure hydrothermal method and sintered at 500 ℃ has very good photocatalytic activity to rhodamine B [3]However, based on the demand for multi-level structure growth control, the material preparation in the above research work needs to add strong alkali and organic template agent, or needs high temperature and high pressure, and through multi-step reaction for a long reaction time to obtain the final material. This is not conducive to cost control, reduction of environmental pollution, etc. High-performance material controllable preparation and cost control, clean synthesis often cannot be achieved. In the process of preparing nano-ZnO by wet chemical method, the interaction between solvent or other additives and Zn 2+ is the key to affecting the nucleation and growth of ZnO, especially the hydroxyl group in the solvent system, which has an important regulating effect on the nucleation and oriented growth of ZnO due to its strong coordination with Zn 2+ , and by regulating the interaction between the hydroxyl group in the solvent and Zn 2+ , controllable preparation of nano-ZnO in a simple system is expected. However, the current research work using alcohol solvents to obtain nano-ZnO all need to obtain the material in a high-pressure hydrothermal reactor, and the pressure in the reaction condition and the morphology of the material are not easy to control. Among them, the research on nano-ZnO multi-level structure currently only uses different chain length alcohols as solvents to obtain nanospheres (secondary structure size less than 50 nm) [4] in a high-pressure hydrothermal reactor at 170°C for 4h. And there are few reports on the synthesis under mild conditions, therefore, the present invention, by taking advantage of the formation characteristics of ZnO in alcohol solvent system, realizes one-step synthesis of nano-ZnO multi-level structure with different morphologies under mild conditions without the need for additional additives and strong alkali, by adjusting the type and concentration of hydroxyl group in the solvent system, and explores its photocatalytic and antibacterial properties. Thus, while maintaining the high activity of ZnO and improving the practicability of nano-ZnO materials, the present invention also realizes cost reduction and environmental pollution reduction, which has important significance for the practical application of ZnO materials.

[0004] [1] Xiaofang Qin, Honglan Cai, Feng Wang, Ping Yin, Xiaofeng Zhang. Facile morphology-controllable synthesis and growth mechanism of ZnO nanostructures with excellent photocatalytic activity [J]. Applied Physics A, 2022, 128(12): 1093.

[0005] [2] Bin Jiang, Wei Tao, Liupeng Zhao, Tianshuang Wang, Xiaomin Liu, Fangmeng Liu, Xu Yan, Yanfeng Sun, Geyu Lu, Peng Sun. Double-shell zno hollow microspheres prepared by template-free method for ethanol detection [J]. Sensors and Actuators B: Chemical, 2023, 385: 133626.

[0006] [3] T.V. Arsha Kusumam, Thasleena Panakkal, T. Divya, M.P. Nikhila, M. Anju, K. Anas, N.K. Renuka. Morphology controlled synthesis and photocatalytic activity of zinc oxide nanostructures [J]. Ceramics International, 2016, 42(3): 3769-3775.

[0007] [4] Ankica Ines Goran Alcoholic solvent influence on zno synthesis: A joint experimental and theoretical study [J]. The Journal of Physical Chemistry C, 2019, 123(48): 29394-29407. SUMMARY

[0008] In order to realize the convenient and controllable green synthesis of high-activity nano ZnO multi-level structure, the formation characteristics of ZnO are utilized, a new method for preparing nano ZnO multi-level structure materials with different morphologies by one-step method in a simple green system of ethylene glycol-monohydric alcohol-water as a mixed solvent at normal pressure and in a lower temperature range is provided, and high-activity bowl-shaped multi-level structure of nano ZnO self-assembled is obtained for the first time in a simple system which is mild and does not need additional additives or strong alkali.

[0009] The technical scheme adopted by the present application is:

[0010] The application provides a high-catalytic and antibacterial activity nano ZnO multi-level structure material synthesis method, which comprises the following steps:

[0011] Step 1: taking zinc acetate as raw material, dissolving it in a solvent at room temperature;

[0012] Step 2: adding deionized water drop by drop under heating and refluxing;

[0013] Step 3: centrifuging while hot, and washing and drying to obtain the nano ZnO multi-level structure material with high catalytic and antibacterial activity.

[0014] The nano ZnO multi-level structure material is used as a photocatalyst or antibacterial activity material.

[0015] The nano ZnO multi-level structure material is a multi-level structure with different sizes and is assembled by nano ZnO secondary structures with a wurtzite structure, wherein the average particle size of the nano ZnO multi-level structure material is 100-800 nm, and the average particle size of the secondary structure of the nano ZnO multi-level structure material is 5-50 nm.

[0016] In step 1, the zinc acetate is one of anhydrous zinc acetate and zinc acetate containing crystal water; the concentration of the dissolved zinc acetate is 0.01-0.1 mol / L, and is preferably 0.02-0.05 mol / L; and the dissolving is magnetic stirring until complete dissolution.

[0017] In step 1, the solvent is a mixed solution of ethylene glycol and an organic reagent, wherein the organic reagent is selected from one of methanol, ethanol, n-propanol, isopropanol, n-butanol, n-pentanol, phenol and acetone, and is preferably one of methanol, ethanol and phenol; and the volume ratio of the ethylene glycol to the organic reagent is 1:0-0:1, and preferably the volume ratio of the ethylene glycol to methanol is 1:2-2:1.

[0018] In step 2, the temperature is raised to a refluxing temperature, the refluxing temperature is 50-90 ℃, and is preferably 60-80 ℃; and the refluxing time is 0.5-24 h, and is preferably 1-9 h.

[0019] In step 2, the volume ratio between the solvent and the deionized water is 3:1-12:1, and is preferably 6:1-10:1.

[0020] In step 3, the centrifugal speed is 8000-10000 rpm, and the centrifugal time is 2-4 min; the washing is washing with methanol or ethanol for 3-5 times; and the drying is drying in air at 40-60 ℃ for 6-12 h.

[0021] The nano ZnO material is one of a bowl-shaped structure, a cauliflower-shaped structure, a hemispherical structure and a donut-shaped structure, and is preferably one of a bowl-shaped structure and a cauliflower-shaped structure.

[0022] The specific surface area of the nano-ZnO material is 6-100 m 2 / g, preferably the specific surface area is 60-100 m 2 / g; the bowl diameter of the semi-bowl-shaped nano-ZnO material is 300-500 nm.

[0023] The nano-ZnO material has the characteristics of photocatalytic degradation of organic dyes and drug waste as a photocatalyst, is a catalyst for photodegradation of methylene blue and rhodamine B, and the catalytic efficiency is 95% or more, and the catalytic efficiency does not decrease significantly after 5-9 times of reuse.

[0024] The nano-ZnO material has the characteristics of antibacterial activity as an antibacterial active material, is a broad-spectrum bacteriostatic agent for inhibiting Escherichia coli and Staphylococcus aureus, wherein the minimum bacteriostatic concentration is 0.1 mg / mL and the minimum bactericidal concentration is 0.1 mg / mL as an Escherichia coli bacteriostatic agent, the minimum bacteriostatic concentration is 0.025 mg / mL and the minimum bactericidal concentration is 0.4 mg / mL as a Staphylococcus aureus bacteriostatic agent. As an Escherichia coli bacteriostatic agent, the bactericidal rate is 96% or more at the minimum bactericidal concentration; as a Staphylococcus aureus bacteriostatic agent, the bactericidal rate is 98% or more at the minimum bactericidal concentration.

[0025] Compared with the prior art, the beneficial effects of the present application are:

[0026] (1) The bowl-shaped structure, cauliflower-shaped structure, semi-spherical structure or doughnut-shaped structure of the ZnO multi-level structure material is obtained by a one-step method under mild conditions using a mixed solvent system for the first time.

[0027] (2) The preparation method is simple, green and environmentally friendly, the reaction temperature is only 60-90 DEG C, no strong alkali or organic template is introduced to increase environmental pollution, and high-temperature sintering is not required, so that the final nano-ZnO material can be obtained.

[0028] (3) The obtained nano-ZnO material has excellent photocatalytic degradation of organic dyes and excellent antibacterial properties. The nano-ZnO material has the characteristics of photocatalytic degradation of organic dyes and drug waste as a photocatalyst, is a catalyst for photodegradation of methylene blue and rhodamine B, and the catalytic efficiency is 95% or more, and the catalytic efficiency does not decrease significantly after 5-9 times of reuse. The ZnO material has the characteristics of antibacterial activity as an antibacterial active material, is a broad-spectrum bacteriostatic agent for inhibiting Escherichia coli and Staphylococcus aureus, wherein the minimum bacteriostatic concentration is 0.1 mg / mL and the minimum bactericidal concentration is 0.1 mg / mL as an Escherichia coli bacteriostatic agent, the minimum bacteriostatic concentration is 0.025 mg / mL and the minimum bactericidal concentration is 0.4 mg / mL as a Staphylococcus aureus bacteriostatic agent. As an Escherichia coli bacteriostatic agent, the bactericidal rate is 96% or more at the minimum bactericidal concentration; as a Staphylococcus aureus bacteriostatic agent, the bactericidal rate is 98% or more at the minimum bactericidal concentration. BRIEF DESCRIPTION OF DRAWINGS

[0029] Figure 1X-ray powder diffraction pattern (XRD) of sample 1;

[0030] Figure 2 Scanning electron microscope (SEM) image of bowl-like ZnO hierarchical structure of sample 1;

[0031] Figure 3 Scanning electron microscope (SEM) image of hemispherical ZnO hierarchical structure of sample 9;

[0032] Figure 4 Scanning electron microscope (SEM) image of flower-like ZnO hierarchical structure of sample 13;

[0033] Figure 5 Scanning electron microscope (SEM) image of doughnut-like ZnO hierarchical structure of sample 15;

[0034] Figure 6 Adsorption-desorption isotherm of sample 1 under N2 atmosphere;

[0035] Figure 7 Experimental data of photodegradation of methylene blue of sample 1;

[0036] Figure 8 Experimental data of photodegradation of rhodamine B of sample 1;

[0037] Figure 9 Plate growth during minimum bactericidal concentration determination of sample 1 against E. coli. DETAILED DESCRIPTION

[0038] The application will be further described below in conjunction with the drawings and specific examples, but the application is not limited to these examples.

[0039] Unless otherwise specified, the raw materials in the examples of the application are purchased through commercial channels. Unless otherwise specified, the test methods are conventional methods.

[0040] The analysis methods in the examples of the application are as follows:

[0041] The structure of the sample is analyzed by X-ray powder diffraction, and the instrument is SmartLab SE of Japan Rikagaku Co., Ltd.

[0042] The morphology of the sample is analyzed by scanning electron microscopy, and the instrument is SAPPHIRE series SUPRA 55 of Germany ZEISS Co., Ltd., and the test conditions are 10-90°, 10° / min.

[0043] The specific surface area of the sample is analyzed by BET, and the instrument is BSD-660S A6 full-automatic specific surface and porosity analyzer, and the test conditions are N2, 77.3K / 1.8(mm / H)

[0044] Example 1

[0045] A certain amount of anhydrous zinc acetate was dissolved in 90 mL of a mixed solvent of ethylene glycol-methanol (volume ratio of 2:1) at room temperature under magnetic stirring to obtain a zinc acetate solution with a concentration of 0.06 mol / L. The solution was heated to 70°C under magnetic stirring, 10 mL of deionized water was added dropwise at a rate of 1 drop per second, refluxed for 3 h, centrifuged at 8000 rpm for 4 min while hot, washed with methanol for 3 times, and dried at 40°C for 12 h to obtain bowl-shaped nano-ZnO multi-level structures, which were recorded as sample 1. Figure 2

[0046] Example 2

[0047] A certain amount of anhydrous zinc acetate was dissolved in 90 mL of a mixed solvent of ethylene glycol-methanol (volume ratio of 1.5:1) at room temperature under magnetic stirring to obtain a zinc acetate solution with a concentration of 0.03 mol / L. The solution was heated to 80°C under magnetic stirring, 10 mL of deionized water was added dropwise at a rate of 1 drop per second, refluxed for 2 h, centrifuged at 8000 rpm for 4 min while hot, washed with methanol for 3 times, and dried at 40°C for 12 h to obtain bowl-shaped nano-ZnO multi-level structures, which were recorded as sample 2.

[0048] Example 3

[0049] A certain amount of anhydrous zinc acetate was dissolved in 90 mL of a mixed solvent of ethylene glycol-methanol (volume ratio of 1.5:1) at room temperature under magnetic stirring to obtain a zinc acetate solution with a concentration of 0.06 mol / L. The solution was heated to 60°C under magnetic stirring, 10 mL of deionized water was added dropwise at a rate of 1 drop per second, refluxed for 3 h, centrifuged at 8000 rpm for 4 min while hot, washed with ethanol (or methanol) for 3 times, and dried at 40°C for 12 h to obtain bowl-shaped nano-ZnO multi-level structures, which were recorded as sample 3.

[0050] Example 4

[0051] A certain amount of anhydrous zinc acetate was dissolved in 90 mL of a mixed solvent of ethylene glycol-methanol (volume ratio of 2:1) at room temperature under magnetic stirring to obtain a zinc acetate solution with a concentration of 0.01 mol / L. The solution was heated to 90°C under magnetic stirring, 10 mL of deionized water was added dropwise at a rate of 1 drop per second, refluxed for 1 h, centrifuged at 8000 rpm for 4 min while hot, washed with methanol for 3 times, and dried at 40°C for 12 h to obtain bowl-shaped nano-ZnO multi-level structures, which were recorded as sample 4.

[0052] Example 5

[0053] ​A certain amount of zinc acetate with two crystal water was weighed, and dissolved in 90 mL of ethylene glycol-methanol (volume ratio of 1.5:1) mixed solvent at room temperature under magnetic stirring to obtain a zinc acetate solution with a concentration of 0.04 mol / L. The solution was heated to 80°C under magnetic stirring, and 9 mL of deionized water was added dropwise at a rate of 1 drop per second. After refluxing for 2 h, the solution was centrifuged at 8000 rpm for 4 min while hot, and washed with methanol for 3 times. The bowl-shaped nano-ZnO multi-level structure was obtained after drying at 40°C for 12 h, and was recorded as sample 5.

[0054] Example 6

[0055] A certain amount of anhydrous zinc acetate was weighed, and dissolved in 90 mL of ethylene glycol-ethanol (volume ratio of 3:1) mixed solvent at room temperature under magnetic stirring to obtain a zinc acetate solution with a concentration of 0.05 mol / L. The solution was heated to 80°C under magnetic stirring, and 10 mL of deionized water was added dropwise at a rate of 1 drop per second. After refluxing for 2 h, the solution was centrifuged at 8000 rpm for 4 min while hot, and washed with ethanol for 3 times. The bowl-shaped nano-ZnO multi-level structure was obtained after drying at 40°C for 12 h, and was recorded as sample 6.

[0056] Example 7

[0057] A certain amount of anhydrous zinc acetate was weighed, and dissolved in 50 mL of ethylene glycol-methanol (volume ratio of 1.5:1) mixed solvent at room temperature under magnetic stirring to obtain a zinc acetate solution with a concentration of 0.01 mol / L. The solution was heated to 90°C, and 10 mL of deionized water was added dropwise at a rate of 1 drop per second. After refluxing for 3 h, the solution was centrifuged at 8000 rpm for 4 min while hot, and washed with methanol for 3 times. The cauliflower-shaped nano-ZnO multi-level structure was obtained after drying at 40°C for 12 h, and was recorded as sample 7.

[0058] Example 8

[0059] A certain amount of anhydrous zinc acetate was weighed, and dissolved in 50 mL of ethylene glycol-methanol (volume ratio of 1:1) mixed solvent at room temperature under magnetic stirring to obtain a zinc acetate solution with a concentration of 0.03 mol / L. The solution was heated to 60°C, and 9 mL of deionized water was added dropwise at a rate of 1 drop per second. After refluxing for 3 h, the solution was centrifuged at 8000 rpm for 4 min while hot, and washed with methanol for 3 times. The cauliflower-shaped nano-ZnO multi-level structure was obtained after drying at 40°C for 12 h, and was recorded as sample 8.

[0060] Example 9

[0061] A certain amount of anhydrous zinc acetate was dissolved in 90 mL of ethylene glycol-n-propanol (volume ratio of 1.5:1) mixed solvent at room temperature under magnetic stirring to obtain a zinc acetate solution with a concentration of 0.06 mol / L. The solution was heated to 80°C, 10 mL of deionized water was added dropwise at a rate of 1 drop per second, refluxed for 3 h, and then centrifuged at 8000 rpm for 4 min while hot, and washed with ethanol for 3 times, and dried at 40°C for 12 hours to obtain cauliflower-like nano-ZnO multi-level structures, which are denoted as sample 9. Figure 3

[0062] Example 10

[0063] A certain amount of anhydrous zinc acetate was dissolved in 90 mL of ethylene glycol-n-propanol (volume ratio of 1.5:1) mixed solvent at room temperature under magnetic stirring to obtain a zinc acetate solution with a concentration of 0.06 mol / L. The solution was heated to 80°C, 10 mL of deionized water was added dropwise at a rate of 1 drop per second, refluxed for 3 h, and then centrifuged at 8000 rpm for 4 min while hot, and washed with ethanol for 3 times, and dried at 40°C for 12 hours to obtain cauliflower-like nano-ZnO multi-level structures, which are denoted as sample 9.

[0064] Example 11

[0065] A certain amount of anhydrous zinc acetate was dissolved in 90 mL of ethylene glycol-n-propanol (volume ratio of 1.5:1) mixed solvent at room temperature under magnetic stirring to obtain a zinc acetate solution with a concentration of 0.06 mol / L. The solution was heated to 80°C, 10 mL of deionized water was added dropwise at a rate of 1 drop per second, refluxed for 3 h, and then centrifuged at 8000 rpm for 4 min while hot, and washed with ethanol for 3 times, and dried at 40°C for 12 hours to obtain cauliflower-like nano-ZnO multi-level structures, which are denoted as sample 9.

[0066] Example 12

[0067] A certain amount of anhydrous zinc acetate was dissolved in 90 mL of ethylene glycol-n-propanol (volume ratio of 1.5:1) mixed solvent at room temperature under magnetic stirring to obtain a zinc acetate solution with a concentration of 0.06 mol / L. The solution was heated to 80°C, 10 mL of deionized water was added dropwise at a rate of 1 drop per second, refluxed for 3 h, and then centrifuged at 8000 rpm for 4 min while hot, and washed with ethanol for 3 times, and dried at 40°C for 12 hours to obtain cauliflower-like nano-ZnO multi-level structures, which are denoted as sample 9.

[0068] Example 13

[0069] ​A certain amount of zinc acetate with two crystal water was weighed, and was dissolved in 80 mL of ethylene glycol solvent under magnetic stirring at room temperature to obtain a zinc acetate solution with a concentration of 0.05 mol / L. The solution was heated to 80°C, and 9 mL of deionized water was added dropwise at a rate of 1 drop per second. The solution was refluxed for 3 h, and was centrifuged at 10,000 rpm for 4 min while hot, and was washed with ethanol for 3 times, and was dried at 40°C for 12 h to obtain hemispherical nano-ZnO multi-structures, which were marked as sample 13. Figure 4 ).

[0070] Example 14

[0071] A certain amount of anhydrous zinc acetate was weighed, and was dissolved in 90 mL of ethylene glycol-ethanol (volume ratio of 3:1) solvent under magnetic stirring at room temperature to obtain a zinc acetate solution with a concentration of 0.03 mol / L. The solution was heated to 80°C, and 9 mL of deionized water was added dropwise at a rate of 1 drop per second. The solution was refluxed for 3 h, and was centrifuged at 8,000 rpm for 4 min while hot, and was washed with ethanol for 3 times, and was dried at 40°C for 12 h to obtain hemispherical ZnO multi-structures, which were marked as sample 14.

[0072] Example 15

[0073] A certain amount of anhydrous zinc acetate was weighed, and was dissolved in 90 mL of methanol solvent under magnetic stirring at room temperature to obtain a zinc acetate solution with a concentration of 0.01 mol / L. The solution was heated to 80°C, and 9 mL of deionized water was added dropwise at a rate of 1 drop per second. The solution was refluxed for 6 h, and was centrifuged at 10,000 rpm for 4 min while hot, and was washed with ethanol for 3 times, and was dried at 40°C for 12 h to obtain donut-shaped nano-ZnO, which were marked as sample 15. Figure 5 ).

[0074] Example 16

[0075] A certain amount of anhydrous zinc acetate was weighed, and was dissolved in 90 mL of methanol solvent under magnetic stirring at room temperature to obtain a zinc acetate solution with a concentration of 0.06 mol / L. The solution was heated to 80°C, and 9 mL of deionized water was added dropwise at a rate of 1 drop per second. The solution was refluxed for 6 h, and was centrifuged at 10,000 rpm for 4 min while hot, and was washed with ethanol for 3 times, and was dried at 40°C for 12 h to obtain donut-shaped nano-ZnO, which were marked as sample 16.

[0076] The bowl-shaped nano-ZnO multi-structure was taken as a typical example, and sample 1 was taken as an example for structural characterization. The X-ray powder diffraction pattern thereof is shown in Figure 1 as shown, which is consistent with the ZnO standard card PDF #99-0111, and it can be seen that the material is a high-purity hexagonal wurtzite structure.

[0077] The bowl-shaped nano-ZnO multi-structure was taken as a typical example, and sample 1 was taken for morphology characterization. The scanning electron microscope characterization thereof is shown in Figure 2As shown, the bowl-like multi-level structure formed by the assembly of nanosphere substructures with size less than 10 nm, the overall size is about 500-600 nm affected by local concentration, and the caliber of the bowl is about 300-400 nm.

[0078] The specific surface area test was performed on sample 1, and the adsorption-desorption isotherm under N2 atmosphere was as shown in Figure 6 The measured specific surface area was 63.935 m 2 / g.

[0079] The photocatalytic degradation of methylene blue was tested on sample 1, taking the bowl-like nano-ZnO multi-level structure as an example. 20 mg of sample 1 was placed in 40 mL of 20 ppm methylene blue aqueous solution, and ultrasonic was performed for 10 min in the dark. After the dye molecules on the surface of the catalyst reached adsorption-desorption equilibrium, it was placed in a self-made photocatalytic reaction device equipped with a 250 W mercury lamp (λ ax ≈365 nm) and a magnetic stirrer. 2 ml of the above mixture was taken at different time points (0-180 min, every 30 min) and added to 2 ml of methanol, mixed well, and then centrifuged at 10000 rpm for 5 min. The supernatant was taken and the absorbance value at wavelength 664 nm was measured using a UV-visible spectrophotometer. The absorbance change curve is as shown in Figure 7 The results show that the degradation efficiency is as high as 96.9% in 2 h and close to 100% in 3 h.

[0080] The photocatalytic degradation of rhodamine B was tested on sample 1, taking the bowl-like nano-ZnO multi-level structure as an example. 20 mg of sample 1 was placed in 40 mL of 5 ppm rhodamine B aqueous solution, and ultrasonic was performed for 10 min in the dark. After the dye molecules on the surface of the catalyst reached adsorption-desorption equilibrium, it was placed in a self-made photocatalytic reaction device equipped with a 250 W mercury lamp (λ ax ≈365 nm) and a magnetic stirrer. 2 ml of the above mixture was taken at different time points (0-180 min, every 30 min) and added to 2 ml of methanol, mixed well, and then centrifuged at 10000 rpm for 5 min. The supernatant was taken and the absorbance value at wavelength 553 nm was measured using a UV-visible spectrophotometer. The absorbance change curve is as shown in Figure 8 The results show that the degradation efficiency is as high as 97.9% in 2 h and close to 100% in 3 h.

[0081] The above-mentioned sample is subjected to antibacterial performance test, and sample 1 (bowl-shaped zinc oxide) is taken as an example. The mother liquor sample added with a certain amount of culture medium is subjected to gradient dilution (0.4 mg / ml, 0.2 mg / ml, 0.1 mg / ml, 0.05 mg / ml, 0.025 mg / ml, 0.0125 mg / ml) by using double dilution method, and the result is judged after incubation for 16-20 h in a common air incubator at 35 ℃. When the bacteria in the sample 1 solution-free hole grow obviously, the corresponding concentration in the hole in which no colony is obviously grown is the minimum inhibitory concentration (MIC) of sample 1.

[0082] The minimum bactericidal concentration of sample 1 is determined by coating method counting method. 0.1 mL of solution with different ZnO concentrations is taken from the clear tube and coated on the surface of the culture medium, and the number of colonies is counted after incubation for a certain time. The lowest dilution sample concentration in which the number of colonies is less than 5 is determined as the minimum bactericidal concentration (MBC).

[0083] The results are shown in Table 1. Figure 9 The minimum inhibitory concentration of sample 1 on Escherichia coli is 0.1 mg / mL, and the minimum bactericidal concentration is 0.1 mg / mL; the minimum inhibitory concentration of sample 1 on Staphylococcus aureus is 0.025 mg / mL, and the minimum bactericidal concentration is 0.4 mg / mL.

[0084] The nano-ZnO multi-level structure material in the application has a large specific surface area, high light conversion efficiency and surface active sites, and thus has excellent photocatalytic and antibacterial properties.

[0085] The above are only several embodiments of the application, and do not limit the application in any form. Although the application is disclosed with the preferred embodiments, it is not intended to limit the application. Any skilled person in the art can make some changes or modifications to the disclosed technical content without departing from the scope of the application, and the equivalent embodiments are equivalent to the equivalent embodiments, which are within the scope of the technical solution.

Claims

1. A method for synthesizing a high-catalytic and antibacterial activity nano-ZnO multi-level structure material, characterized in that, The nano-ZnO multi-level structure material as a photocatalyst or antibacterial active material, the synthesis method comprises the following steps: Step 1: taking zinc acetate as raw material, dissolving it in a solvent at room temperature; Step 2: heating, adding deionized water dropwise, refluxing; Step 3: centrifuging, washing, drying to obtain the nano-ZnO multi-level structure material with high catalytic and antibacterial activity; The nano-ZnO multi-level structure material is a multi-level structure of different sizes, which is assembled by nano-ZnO secondary structures of wurtzite structure, wherein the average particle size of the secondary structure in the nano-ZnO multi-level structure material is 5-50 nm, and the average particle size of the multi-level structure is 100-800 nm; The solvent is methanol, or a mixed solution of ethylene glycol and an organic reagent, wherein the organic reagent is selected from any one of methanol, ethanol, n-propanol, isopropanol, n-butanol, n-pentanol and phenol; the volume ratio of ethylene glycol to the organic reagent is 1:0-1:1; In step 2, the temperature is raised to the refluxing temperature, the refluxing temperature is 50-90 DEG C, and the refluxing time is 0.5-24 h; the deionized water is added dropwise at a speed of 1 drop per second; the ratio between the solvent and the deionized water is 3:1-12:1 in volume ratio; In step 3, the centrifugation is hot centrifugation, the centrifugal speed is 8000-10000 rpm, and the centrifugation time is 2-4 minutes; The nano ZnO multi-level structure material is one of a bowl structure, a cauliflower structure, a semi-spherical structure and a doughnut structure; and the specific surface area of the nano ZnO multi-level structure material is 6-100 m 2 / g.

2. The method according to claim 1, wherein the method is characterized by, In step 1, the zinc acetate is any one of anhydrous zinc acetate and zinc acetate containing crystal water, and the concentration of the dissolved zinc acetate is 0.01-0.1 mol / L; The dissolution is magnetic stirring until complete dissolution.

3. The method according to claim 2, wherein the method is characterized by, The concentration of the dissolved zinc acetate is 0.02-0.05 mol / L; The organic reagent is selected from any one of methanol, ethanol and phenol.

4. The method according to claim 2, wherein the method is characterized by, The organic reagent is selected from methanol, and the volume ratio of ethylene glycol to methanol is 2:1-1:

1.

5. The method of claim 1, wherein the method is characterized by, The refluxing temperature is 60-80 DEG C; The ratio between the solvent and the deionized water is 6:1-10:1 in volume ratio; The refluxing time is 1-9 h.

6. The method of claim 1, wherein the method is characterized by, The washing is washing with methanol or ethanol for 3-5 times; The drying is drying in air at 40-60 DEG C for 6-12 h.

7. The method according to claim 1, wherein the method is characterized by, The nano ZnO multi-level structure material is one of a bowl-shaped structure and a semi-spherical structure, and the specific surface area is 60-100 m 2 / g.

8. The method according to claim 1, wherein the method is characterized by, The nano-ZnO multi-level structure material as an antibacterial active material has antibacterial properties, and is a broad-spectrum bacteriostatic agent for inhibiting escherichia coli and staphylococcus aureus; when used as an escherichia coli bacteriostatic agent, the minimum bacteriostatic concentration is 0.1 mg / mL, the minimum bactericidal concentration is 0.1 mg / mL, and the bactericidal rate is more than 96% at the minimum bactericidal concentration; when used as a staphylococcus aureus bacteriostatic agent, the minimum bacteriostatic concentration is 0.025 mg / mL, the minimum bactericidal concentration is 0.4 mg / mL, and the bactericidal rate is more than 98% at the minimum bactericidal concentration.

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