Controllable Growth And Formation Mechanism Of ZnO Microstructure

Zinc oxide(ZnO)is a semiconductor material with a band gap of 3.37 ev and an intrinsic conductivity type of n-type.The material itself is non-toxic,low preparation cost and has large exciton binding energy(60 MeV).It is widely used in solar cells,photocatalysis,light emitting diodes,piezoelectric devices,acoustooptic devices,gas sensors,antibacterial materials and other fields.The characteristics of ZnO semiconductor material are closely related to its microstructure.When the specific surface area is large,its photoelectric characteristics are more ideal.Therefore,it is of great significance for the application of ZnO in the semiconductor field to study the formation mechanism of ZnO micro nano structure and realize its controllable growth.In recent years,a variety of metal antibacterial products have appeared in the market,most of which take silver as the main antibacterial material,including antibacterial textiles,antibacterial coatings,antibacterial plastics and so on.When metal is prepared into nano metal powder,its properties have changed greatly.Nano sized metal particles can easily enter bacteria and greatly improve the antibacterial property of metal.Therefore,all metals with nano particle size have a certain degree of antibacterial property.Nano metal powder has broad application prospects in the field of antibacterial materials.With the further study of the characteristics of ZnO micro nanostructures,it is found that there is great room for progress in antibacterial properties.ZnO can also be used as antibacterial materials in the field of medical care.The research shows that these properties can be improved by constructing ZnO composites.This paper obtained ZnO micro and nanomaterials with different morphologies by chemical vapor deposition(CVD)and hydrothermal methods.They were modified in different ways,and the growth mechanism and antibacterial properties of ZnO micro and nanomaterials were studied.The main research contents include the following aspects:(1)Using the CVD method,ZnO micro nanorods were prepared by a redox reaction between ZnO powder and carbon powder under different oxygen concentration and nitrogen concentration ratios.The controllable growth and formation mechanism of the ZnO micro nanostructure were studied.The results show that the surface of ZnO micro nanorods becomes smooth with the increase of oxygen concentration.When the oxygen concentration is 30 sccm,the reaction environment is thermodynamic equilibrium.The morphology of ZnO micro nanorods is better and has a hexagonal wurtzite structure;When the concentration of oxygen and nitrogen is 1:2,hexagonal wurtzite micro nanorods with a more acceptable diameter and smoother surface are formed.(2)The surface of ZnO micro nanorods prepared by CVD was plated with copper by hydrothermal method.Comparing the differences between copper doped and noncopper doped samples,it can be seen from the material selections that the zinc oxide micro nanorods after copper plating show that there are blue particles.Using SEM to characterize the morphology of the samples obtained from the experiment,it can be seen that the surface structure of zinc oxide micro nanorods after copper plating changes obviously,there are many wrinkled walls,and the specific surface area of zinc oxide micro nanorods is increased.(3)In the sterilization experiment of zinc oxide micro nanorods,four typical representative strains were selected: Escherichia coli,Staphylococcus aureus,Bacillus subtilis,and Bacillus cereus.During the investigation,the optimal conditions for the sterilization performance of ZnO micro nanostructures were explored by changing the type of sterilization agent,sterilization light environment,and sterilization temperature environment.The experimental results show that the more advanced the bactericide material is,the better the bactericidal effect is.This is because its diameter is between micro and nano;it has a large specific surface area and can better contact the reactants to maximize the reaction of the bactericide.The bactericidal effect of copper-doped ZnO micro nanorods is significantly improved,indicating that metal ion doping can optimize material properties.In addition,light significantly impacts the bactericidal performance of zinc oxide micro nanorods.As a semiconductor material,the characteristics of photocatalysis significantly improve its bactericidal ability under different light conditions.Due to the particular wavelength of mercury light(wavelength 491.60nm)and sodium light(wavelength 589.6nm),the sterilization rate of ZnO micro nanorods is increased to more than 95%.