阅读说明：本技术 一种可见光催化纳米抗菌材料及其制备方法 (Visible light catalytic nano antibacterial material and preparation method thereof ) 是由 冷冰 郭澍 张兴来 于 2020-12-21 设计创作，主要内容包括：本发明属于纳米抗菌材料和环境保护领域,特别是指一种可见光催化纳米抗菌材料及其制备方法。该抗菌材料是以GaN为主晶格、ZnO固溶的GaN:ZnO四元合金纳米颗粒。其中,ZnO的固溶度为23～30at％,禁带宽度在2.3～2.6eV之间。该纳米抗菌材料有着很大的比表面积、合适的能带结构,在保证较强氧化还原能力的同时还兼具优异的可见光吸收性能。Zn～(2+)和Ga～(3+)离子的释放以及光照下所产生的·OH共同导致了细菌细胞壁的破坏,从而可以有效杀死细菌。本发明通过控制形核温度、气流场以及反应物获得了高结晶质量、单相的四元合金材料,解决了目前光催化抗菌材料光响应波段窄、抗菌效率低、抗菌普适性差,以及光催化降解有机物效果差等问题。(The invention belongs to the field of nano antibacterial materials and environmental protection, and particularly relates to a visible light catalytic nano antibacterial material and a preparation method thereof. The antibacterial material is GaN-ZnO quaternary alloy nano particles which take GaN as a main crystal lattice and ZnO is in solid solution. Wherein the solid solubility of ZnO is 23-30 at%, and the forbidden band width is 2.3-2.6 eV. The nano antibacterial material has a large specific surfaceThe product and the proper energy band structure have excellent visible light absorption performance while ensuring stronger oxidation reduction capability. Zn 2+ And Ga 3+ The release of ions and OH generated under illumination cause the destruction of bacterial cell walls, thereby effectively killing bacteria. The invention obtains the single-phase quaternary alloy material with high crystallization quality by controlling the nucleation temperature, the airflow field and the reactant, and solves the problems of narrow photoresponse waveband, low antibacterial efficiency, poor antibacterial universality, poor organic matter photocatalytic degradation effect and the like of the existing photocatalytic antibacterial material.)

1. The visible light catalytic nanometer antibiotic material features that the antibiotic material is GaN-ZnO quaternary alloy nanometer grain with GaN as main crystal lattice and ZnO as solid solution.

2. The visible-light-catalyzed nano antibacterial material as claimed in claim 1, wherein the solid solution amount of ZnO is 23 to 30 at%, the forbidden bandwidth of GaN: ZnO quaternary alloy nanoparticles is 2.3 to 2.6eV, and the particle size is 6 to 120 nm.

3. The preparation method of the visible light catalytic nano antibacterial material of claim 1 or 2, which is characterized by comprising the following steps:

step 1: ga (NO)₃)₃·xH₂O and Zn (CH)₃COO)₂·2H₂Mixing O into ethylene glycol monomethyl ether solution, adding ethanolamine as a stabilizer, stirring for 1-3 hours at 50-70 ℃ to form transparent colloid, and placing the colloid in a tube furnace to heat for 8-12 hours at 400-500 ℃ to form Zn-Ga-O precursor powder;

step 2: physically mixing and grinding Zn-Ga-O precursor powder and ZnO powder, placing the mixture in a first corundum crucible, placing the first corundum crucible filled with the mixed powder in a quartz tube with the diameter smaller than that of a cavity of the tubular furnace, and placing the quartz tube filled with the first corundum crucible in the center of the tubular furnace; placing another second corundum crucible filled with ZnO powder and carbon powder on the side surface of the first corundum crucible and positioned at NH₃Upstream in the direction of gas flow; an empty third corundum crucible was placed on the side of the second corundum crucible at the NH position₃Upstream in the direction of gas flow; then, introducing inert atmosphere into the tube furnace to remove the tube furnace chamberResidual oxygen in the body;

and step 3: heating the cavity of the high-temperature tube furnace, closing the inert atmosphere when the temperature rises to 1000-1100 ℃, and introducing NH₃Gas; keeping the temperature for 20-25 min, reducing the temperature to 800-900 ℃, and continuing to react for 35-40 min; NH shut off₃And naturally cooling the tubular furnace to room temperature by gas, and obtaining the GaN-ZnO quaternary alloy nano particles in the first corundum crucible.

4. The method for preparing visible light catalytic nano antibacterial material according to claim 3, wherein in step 1, Ga (NO) is calculated according to weight portion₃)₃·xH₂9 to 10 parts of O and Zn (CH)₃COO)₂·2H₂8-9 parts of O, 80-120 parts of ethylene glycol monomethyl ether solution and 4-5 parts of ethanolamine.

5. The preparation method of the visible-light-catalyzed nano antibacterial material as claimed in claim 3, wherein in the step 2, the molar ratio of the Zn-Ga-O precursor powder to the ZnO powder is 1:2 to 1: 5.

6. The method for preparing visible light catalytic nano antibacterial material according to claim 3, wherein in the step 2, one section of the quartz tube is sealed, the other end is opened, and the sealed end is located at NH₃Downstream in the direction of gas flow, open end at NH₃Upstream in the direction of flow of the gas.

7. The preparation method of the visible light catalytic nano antibacterial material according to claim 3, wherein in the step 2, the molar ratio of ZnO powder to carbon powder in the second corundum crucible is 2-4: 1.

8. The method for preparing a visible light catalytic nano antibacterial material according to claim 3, characterized in that in step 2, the distance between the second corundum crucible and the first corundum crucible is 0-1 cm, and the distance between the third corundum crucible and the second corundum crucible is 0.5-2 cm.

9. The method for preparing the visible light catalytic nano antibacterial material according to claim 3, wherein in the step 3, NH is added₃The gas flow is 2 to 10 sccm.

10. The method for preparing the visible light catalytic nano antibacterial material according to claim 3, wherein in the step 3, the inert atmosphere is argon or nitrogen.

Technical Field

The invention belongs to the field of nano antibacterial materials and environmental protection, and particularly relates to a visible light catalytic nano antibacterial material and a preparation method thereof.

Background

The rapid development of industrial modernization brings about serious environmental pollution problems, and the solution of the environmental pollution problems is a necessary condition for realizing sustainable development of human society, wherein the pollution problem of drinking water seriously affects human health and living standard. Harmful microorganisms in drinking water can cause the prevalence of various diseases, particularly infectious diseases. The traditional method for disinfecting drinking water is to add a disinfectant, but some disinfection byproducts generated in the process also have different degrees of influence on the long-term health of human beings.

In order to overcome the defects of the traditional drinking water disinfection method, researches on sterilization and disinfection by a photocatalysis technology gradually enter the field of people. Matsunaga et al first reported TiO in 1985₂The research results related to the photocatalytic inactivation of escherichia coli open the way for the application of the photocatalytic technology in the disinfection field. The active groups generated in the photocatalysis process can kill bacteria, can not generate byproducts, and effectively avoids the problem of secondary pollution. However, with TiO₂And ZnO and the like are the most widely researched photocatalytic materials at present, but the spectral response range of the metal oxide is narrow, and the metal oxide can only absorb ultraviolet light, and only 3 percent of sunlight is ultraviolet light. Therefore, the utilization rate of solar energy is improved, and the development of efficient visible light response photocatalyst has very important significance for promoting the application of the photocatalytic technology.

GaN: ZnO quaternary alloys have received much attention because of their tunable bandgaps. As the content of ZnO increases, the band gap of the GaN ZnO quaternary alloy can be continuously adjusted from 3.4eV to 2.2 eV. Although GaN: ZnO nanoparticles have been prepared by Maida in 1994 for a long time and show good photocatalytic properties, hetero-phases are easily introduced during the preparation process, and Zn is easily volatile at high temperature to cause low solid solubility of ZnO. Meanwhile, the antibacterial agent has no application in the antibacterial field.

Disclosure of Invention

In order to solve the problems in the prior art, the invention aims to provide a visible light catalytic nano antibacterial material which is wide in visible light absorption range, good in antibacterial performance and low in cost, a preparation method thereof and an application field thereof is widened.

In order to achieve the purpose, the technical scheme of the invention is as follows:

a visible light catalytic nano antibacterial material is prepared from GaN as main lattice and ZnO as solid solution of GaN-ZnO quaternary alloy nanoparticles.

According to the visible light catalytic nano antibacterial material, the solid solution amount of ZnO is 23-30 at%, the forbidden band width of GaN-ZnO quaternary alloy nano particles is 2.3-2.6 eV, and the particle size is 6-120 nm.

The preparation method of the visible light catalytic nano antibacterial material specifically comprises the following steps:

step 1: ga (NO)₃)₃·xH₂O and Zn (CH)₃COO)₂·2H₂Mixing O into ethylene glycol monomethyl ether solution, adding ethanolamine as a stabilizer, stirring for 1-3 hours at 50-70 ℃ to form transparent colloid, and placing the colloid in a tube furnace to heat for 8-12 hours at 400-500 ℃ to form Zn-Ga-O precursor powder;

step 2: physically mixing and grinding Zn-Ga-O precursor powder and ZnO powder, placing the mixture in a first corundum crucible, placing the first corundum crucible filled with the mixed powder in a quartz tube with the diameter smaller than that of a cavity of the tubular furnace, and placing the quartz tube filled with the first corundum crucible in the center of the tubular furnace; placing another second corundum crucible filled with ZnO powder and carbon powder on the side surface of the first corundum crucible and positioned at NH₃Upstream in the direction of gas flow; an empty third corundum crucible was placed on the side of the second corundum crucible at the NH position₃Upstream in the direction of gas flow; then, introducing inert atmosphere into the tube furnace to remove residual oxygen in the cavity of the tube furnace;

and step 3: heating the cavity of the high-temperature tube furnace, closing the inert atmosphere when the temperature rises to 1000-1100 ℃, and introducing NH₃Gas; keeping the temperature for 20-25 min, reducing the temperature to 800-900 ℃, and continuing to react for 35-40 min; closing deviceClosed NH₃And naturally cooling the tubular furnace to room temperature by gas, and obtaining the GaN-ZnO quaternary alloy nano particles in the first corundum crucible.

The preparation method of the visible light catalytic nano antibacterial material comprises the step 1 of adding Ga (NO) in parts by weight₃)₃·xH₂9 to 10 parts of O and Zn (CH)₃COO)₂·2H₂8-9 parts of O, 80-120 parts of ethylene glycol monomethyl ether solution and 4-5 parts of ethanolamine.

In the preparation method of the visible light catalytic nano antibacterial material, in the step 2, the molar ratio of Zn-Ga-O precursor powder to ZnO powder is 1: 2-1: 5.

In the step 2, one section of the quartz tube is sealed, the other end of the quartz tube is opened, and the sealed end is positioned at NH₃Downstream in the direction of gas flow, open end at NH₃Upstream in the direction of flow of the gas.

In the preparation method of the visible light catalytic nano antibacterial material, in the step 2, the molar ratio of ZnO powder to carbon powder in the second corundum crucible is 2-4: 1.

In the step 2, the distance between the second corundum crucible and the first corundum crucible is 0-1 cm, and the distance between the third corundum crucible and the second corundum crucible is 0.5-2 cm.

The preparation method of the visible light catalytic nano antibacterial material comprises the step 3 of NH₃The gas flow is 2 to 10 sccm.

In the preparation method of the visible light catalytic nano antibacterial material, in the step 3, the inert atmosphere is argon or nitrogen.

The design idea of the invention is as follows:

on one hand, the invention can ensure that the alloy takes GaN as a main crystal lattice and can also improve the content of ZnO through the cooling preparation process and the addition of ZnO in the initial reactant. The appropriate ZnO content can ensure that the appropriate band gap absorbs visible light, and has higher oxidation-reduction potential, which is beneficial to generating active oxygen and further killing bacteria. In another aspect, the invention isNH can also be adjusted by placing the sealed quartz tube and the hollow corundum crucible₃The gathering time of gas in the reactant and the gas flow field are favorable for forming high-quality GaN-ZnO quaternary alloy. Finally, two antibacterial ions (Zn) are simultaneously contained in one material²⁺，Ga³⁺) The antibacterial efficiency of the material can be greatly improved by dissolving the material in an aqueous solution.

Compared with the prior art, the visible light catalytic nano antibacterial material and the preparation method thereof have the advantages and beneficial effects that:

1) the invention uses large pipe sleeved with small pipe, and the corundum crucible is placed in a quartz pipe with a diameter smaller than that of the cavity of the pipe furnace and is arranged in NH₃An empty corundum crucible is added at the upstream of the gas flow, so that NH can be effectively controlled₃Gas flow field, and quartz tube in NH₃The gas downstream end is sealed to allow NH to flow₃The gas is gathered in the quartz tube for a longer time, so that the nitriding is more sufficient and the intermediate phase is not easy to appear.

2) Because Zn is extremely easy to volatilize at high temperature, in order to ensure the doping amount of ZnO and improve the Zn content in the alloy, ZnO is additionally added into reactants to be used as a Zn source, and NH is added₃ZnO and carbon powder are additionally added at the upstream end to supplement the Zn content so as to obtain higher ZnO content and further obtain narrower optical band gap.

3) The invention adopts a cooling twice growth method, can ensure that GaN is taken as a main crystal lattice for nucleation at high temperature, and can ensure solid solution of ZnO at low temperature to prevent Zn²⁺And (4) volatilizing the ions.

4) The GaN-ZnO quaternary alloy prepared by the invention has very proper forbidden bandwidth, not only ensures effective visible light absorption, but also ensures that the alloy material has very strong oxidation-reduction capability.

5) The GaN-ZnO quaternary alloy prepared by the invention can completely inactivate staphylococcus aureus in 90min, inactivate 94% escherichia coli in 120min and completely degrade methylene blue in 120min under the irradiation of visible light, and shows excellent photocatalytic antibacterial and degradation performances.

In a word, the nano antibacterial material has large specific surface area and proper energy band structure, and ensures stronger oxidation-reduction capabilityAnd simultaneously has excellent visible light absorption performance. Zn²⁺And Ga³⁺The release of ions and OH generated under illumination cause the destruction of bacterial cell walls, thereby effectively killing bacteria. The invention obtains the single-phase quaternary alloy material with high crystallization quality by controlling the nucleation temperature, the airflow field and the reactant, and solves the problems of narrow photoresponse waveband, low antibacterial efficiency, poor antibacterial universality, poor organic matter photocatalytic degradation effect and the like of the existing photocatalytic antibacterial material. Meanwhile, the nano antibacterial material not only shows excellent photocatalytic antibacterial effect under illumination, but also still has antibacterial capability under a dark state. The photocatalyst has the advantages of good sterilization effect, simple preparation method, low cost and easy industrial application.

Drawings

FIG. 1 is a flow chart of preparation of GaN ZnO quaternary alloy nanoparticles.

Fig. 2 is a Scanning Electron Microscope (SEM) image of nanoparticles of a GaN: ZnO quaternary alloy.

FIG. 3 is an X-ray diffraction (XRD) pattern of GaN ZnO quaternary alloy nanoparticles. In the figure, the abscissa 2 θ represents the diffraction angle (degree) and the ordinate Intensity represents the relative Intensity (a.u.).

In FIG. 4, (a) is a Transmission Electron Microscope (TEM) image of GaN: ZnO quaternary alloy nanoparticles; (b) is a High Resolution Transmission Electron Microscope (HRTEM) image of GaN: ZnO quaternary alloy nanoparticles; (c) is the Fast Fourier Transform (FFT) map of figure (d); (d) is a Scanning Transmission Electron Microscope (STEM) image of GaN: ZnO quaternary alloy nanoparticles; (e) - (h) the distribution of elements Ga, Zn, N, O, respectively; (i) is the X-ray Energy spectrum (EDS) of ZnO quaternary alloy nanoparticles, with Energy on the abscissa representing Energy (KeV) and Intensity on the ordinate representing relative Intensity (a.u.).

FIG. 5 is an ultraviolet-visible absorption spectrum of GaN ZnO quaternary alloy nanoparticles, a GaN thin film, and ZnO nanoparticles, with the abscissa wavelet representing Wavelength (nm) and the ordinate Normalized abs representing Normalized absorption intensity (a.u.).

In FIG. 6, (a) is a nitrogen adsorption-desorption isotherm curve of nanoparticles of a GaN: ZnO quaternary alloy, the abscissaRelative pressure represents Relative pressure (P/P)₀) The ordinate Absorbed Volume represents the amount of absorption (cm)³(iv)/g); (b) is the corresponding Pore size distribution curve, the abscissa Pore diameter represents the Pore diameter (nm) and the ordinate dV/dD represents the Pore area (10)^-3cm³/g)。

In FIG. 7, (a) is 0.5mg/mL ZnO and various concentrations of GaN: ZnO quaternary alloy nanoparticles in visible light (. lamda.) (A)>400nm，80mW/cm²) The degradation curve of the lower pair of methylene blue; (b) is a degradation stability curve of GaN ZnO quaternary alloy nano particles repeatedly used for 5 times. In the figure, the abscissa Time represents the illumination Time (min), and the ordinate C represents the illumination Time (min)_t/C₀Represents the concentration ratio of methylene blue after photocatalytic treatment to that before photocatalytic treatment.

FIG. 8 shows salicylic acid in the presence/absence of visible light (. lamda.)>400nm，80mW/cm²) Absorbance at 510nm under irradiation and treatment with different concentrations of GaN: ZnO nanoparticles. In the figure, the abscissa Time represents the light irradiation Time (min), and the ordinate Absorbance represents the relative intensity of Absorbance (a.u.).

FIG. 9 shows that GaN: ZnO quaternary alloy nanoparticles are visible light (lambda)>400nm，80mW/cm²) Photocatalytic antibacterial performance curves under irradiation for (a) escherichia coli and (b) staphylococcus aureus. In the figure, the abscissa Time represents the light irradiation Time (min), and the ordinate Antibacterial rate represents the Antibacterial ratio (%).

FIG. 10 is a photograph showing the plate-coating optical image of the bacterial solution after coculture of GaN ZnO quaternary alloy nanoparticles and Escherichia coli. In the figure, Blank control represents a Blank control group, namely, bacterial liquid is only subjected to illumination treatment without participation of a GaN-ZnO quaternary alloy; the Dark control group is represented by Dark control, namely, only the GaN-ZnO quaternary alloy is added into the bacterial liquid without illumination treatment.

FIG. 11 is a plate-coated optical photograph of a bacterial solution after cocultivation of GaN ZnO quaternary alloy nanoparticles and Staphylococcus aureus. In the figure, Blank control represents a Blank control group, namely, bacterial liquid is only subjected to illumination treatment without participation of a GaN-ZnO quaternary alloy; the Dark control group is represented by Dark control, namely, only the GaN-ZnO quaternary alloy is added into the bacterial liquid without illumination treatment.

FIG. 12Is Zn (a) dissolved in deionized water under different concentrations and soaking time of GaN-ZnO quaternary alloy nano particles²⁺And (b) Ga³⁺The concentration of the ions. In the figure, the abscissa Time represents Time (min), and the ordinate Concentration represents the Concentration (mg/L) of ions dissolved in an aqueous solution.

In FIG. 13, (a) and (b) are SEM images of E.coli cells irradiated with only visible light but not treated with GaN: ZnO nanoparticles; (c) and (d) is an SEM image of E.coli cells not only irradiated with visible light but also treated with GaN: ZnO nanoparticles; (e) and (f) is an SEM image of staphylococcus aureus cells irradiated with visible light only but not treated with GaN: ZnO nanoparticles; (g) and (h) is an SEM image of Staphylococcus aureus cells treated not only with visible light irradiation but also with GaN: ZnO nanoparticles.

FIG. 14 is an antibacterial mechanism diagram of GaN ZnO quaternary alloy nanoparticles.

The specific implementation mode is as follows:

the invention is further described with reference to the following figures and specific examples.

Example (b):

referring to fig. 1, in this embodiment, a method for preparing a visible light catalytic nano antibacterial material includes the following specific steps:

1) 9.59g of Ga (NO)₃)₃·xH₂O (in this example, x is 2) and 8.23g of Zn (CH)₃COO)₂·2H₂O was mixed to 100mL of ethylene glycol monomethyl ether solution, and 4.5mL of ethanolamine was added as a stabilizer, and stirred at 60 ℃ for 2 hours to form a transparent colloid. And placing the colloid in a tube furnace, and heating for 10 hours at 500 ℃ to form Zn-Ga-O precursor powder with the granularity of 10-130 nm.

2) Taking 2g of ZnO powder with the granularity of 20-40 nm, physically mixing and grinding Zn-Ga-O precursor powder and ZnO powder with the molar ratio of 1:3, and then placing the mixture in a first corundum crucible 1. The first corundum crucible 1 filled with the mixed powder is placed in a quartz tube with the diameter smaller than that of the cavity of the tube furnace, and one end of the quartz tube is opened and the other end is sealed. Open end at NH₃Upstream in the direction of gas flow, with the closed end at NH₃Downstream of the flow, a quartz tube equipped with a first corundum crucible 1 was placed in the center of the tube furnace.

ZnO powder with the granularity of 20-40 nm is taken, uniformly mixed with ZnO powder with the molar ratio of 3:1 and carbon powder with the granularity of 6-10 mu m, and then placed in a second corundum crucible 2. Placing a second corundum crucible 2 filled with ZnO powder and carbon powder on the side surface of the first corundum crucible 1 and at NH₃The distance between the first corundum crucible 1 and the second corundum crucible 2 is 0.5cm at the upstream of the air flow direction; an empty third corundum crucible 3 is placed on the side of the second corundum crucible 2 at NH₃The distance between the third corundum crucible 3 and the second corundum crucible 2 is 1cm at the upstream of the air flow direction; then, introducing Ar gas into the tubular furnace to remove residual oxygen in the cavity of the tubular furnace;

3) heating the cavity of the high-temperature tube furnace, closing Ar gas and introducing NH when the temperature rises to 1050 DEG C₃Gas, NH₃The gas flow rate is 7 sccm; keeping the temperature for 25min, reducing the temperature to 800 ℃, and continuing to react for 35 min. NH shut off₃And (3) naturally cooling the tube furnace to room temperature by using gas, and obtaining the GaN-ZnO quaternary alloy nano particles in the first corundum crucible 1.

Referring to fig. 2, it can be seen from SEM images of the GaN ZnO quaternary alloy nanoparticles that the nanoparticles are approximately spherical in morphology and approximately several tens of nanometers in diameter.

Referring to FIG. 3, it can be seen from the XRD pattern of the GaN ZnO quaternary alloy nanoparticles that the nanoparticles are single-phase, the diffraction peak is located between GaN and ZnO, and GaN, ZnO or ZnGa is not found₂O₄The phase (c). The method proves that the single-phase GaN-ZnO quaternary alloy nano particles are successfully prepared.

Referring to fig. 4, it can be seen from TEM image (a) of the GaN: ZnO quaternary alloy nanoparticles that the nanoparticles have uniform morphology and diameters of about several tens of nanometers. Through further analysis of the HRTEM image (b) and FFT (c), the obtained nano-particles have high crystalline quality and are of single crystal structures. And, from the stem (d) and the element distributions (e) to (h), Ga, Zn, N and O elements are uniformly distributed in the nanoparticles. From the EDS spectrum (i), the ZnO content of the GaN-ZnO quaternary alloy nano-particles is about 26 at%, and the forbidden bandwidth of the GaN-ZnO quaternary alloy nano-particles is 2.47 eV.

Referring to fig. 5, it can be seen from the absorption spectra of the GaN: ZnO quaternary alloy nanoparticles, the GaN thin film, and the ZnO nanoparticles that the absorption band edges of pure GaN and ZnO are in the ultraviolet region, while the GaN: ZnO quaternary alloy nanoparticles can absorb visible light below 550 nm. The GaN-ZnO quaternary alloy nano particles prepared by the invention have excellent visible light absorption characteristics.

Referring to FIG. 6, from the nitrogen adsorption-desorption isothermal (a) curve of GaN: ZnO quaternary alloy nanoparticles, it can be seen that the nanoparticles have a macroporous and mesoporous composition, and the specific surface area is as high as 30.1m²(ii) in terms of/g. As can be seen from the pore size distribution curve (b), the diameter distribution of the pores is in the range of 6 to 120nm, and the average pore size and pore volume are about 24.5nm and 0.2cm³/g。

Referring to FIG. 7, from the curve (a) of photocatalytic degradation of methylene blue by GaN ZnO quaternary alloy nanoparticles, it can be seen that 20mg/mL of methylene blue can be completely degraded by 2mg/mL of nanoparticles within 120 min. And, after 5 times of repeated use (b), no significant degradation was observed.

Referring to fig. 8, salicylic acid is used as a molecular probe to detect the presence of OH in the aqueous solution of the GaN: ZnO quaternary alloy nanoparticles. As can be seen, with the increase of the soaking time and the illumination time of the GaN ZnO quaternary alloy nanoparticles in the aqueous solution, the absorption peak of salicylic acid hydroxyl compounds generated by the reaction of salicylic acid and OH at 510nm is gradually increased, and the GaN ZnO quaternary alloy nanoparticles can generate OH with strong oxidizing property in the aqueous solution after being irradiated by visible light.

Referring to FIG. 9, from the photocatalytic antibacterial performance curve of GaN: ZnO quaternary alloy nanoparticles to Escherichia coli (a) and Staphylococcus aureus (b) under visible light (λ >400nm) irradiation, it can be seen that 2mg/mL GaN: ZnO nanoparticles can inactivate 94% of Escherichia coli within 120min under visible light irradiation (see FIG. 10 for a plate coating optical photograph of the co-cultured bacterial solution). Whereas 100% of Staphylococcus aureus was inactivated within 90min (see FIG. 11 for plate-coating photo of co-cultured bacterial suspension). Moreover, even without light, 2mg/mL of nanoparticles inactivated 46.5% of E.coli and 96.7% of S.aureus within 120 min. The prepared GaN-ZnO quaternary alloy nano-particles are proved to have excellent antibacterial performance.

Referring to FIG. 12, from Zn²⁺And Ga³⁺The dissolution curve shows that as the concentration and the soaking time of the GaN-ZnO quaternary alloy nano particles are increased, Zn is added²⁺And Ga³⁺The dissolution concentration of the ions also increases. And Zn²⁺And Ga³⁺The prepared nano-particles have good antibacterial performance, and the simultaneous action of the two ions leads to excellent antibacterial performance of the prepared nano-particles under the conditions of illumination or no illumination.

Referring to fig. 13, both escherichia coli and staphylococcus aureus showed a smooth cell surface and an intact cell wall under only visible light irradiation. Once the GaN-ZnO quaternary alloy nanoparticles are added into the bacterial liquid, no matter Escherichia coli or Staphylococcus aureus shows cell sap loss and severe cell wall damage.

Referring to fig. 14, it can be seen from the antibacterial mechanism diagram of the GaN ZnO quaternary alloy nanoparticles that a large number of electrons and holes are generated inside the nanoparticles when visible light is irradiated to the nanoparticles. The cavity will be associated with H in the bacterial liquid₂O or OH^-The reaction produces OH with strong oxidizing property. Meanwhile, the nano particles soaked in the bacteria liquid can release Zn with antibacterial property²⁺And Ga³⁺Ions. In OH, Zn²⁺And Ga³⁺Under the combined action of ions, the cell wall of the bacteria can be seriously damaged, so that the apoptosis of the bacteria is caused.

The example results show that the GaN-ZnO quaternary alloy nanoparticles prepared by the invention have large specific surface area and strong visible light absorption, and can dissolve out Zn simultaneously²⁺And Ga³⁺The two antibacterial ions show excellent antibacterial performance under both the illumination and the non-illumination conditions. Moreover, the preparation process is simple, the cost is low, and the preparation method is beneficial to application in the fields of environment and medical treatment.

The above description is only an embodiment of the present invention, but the scope of the present invention is not limited thereto, and any modifications or substitutions that can be easily conceived by those skilled in the art within the technical scope of the present invention are included in the scope of the present invention. Therefore, the protection scope of the present invention shall be subject to the protection scope of the claims.