Preparation And Properties Of Zinc Oxide Based Multifunctional Composites

Zinc oxide（ZnO）is a semiconductor material with a wide band gap and large laser binding energy.Due to its special physical,chemical and photoelectric properties,its broad application prospects have stimulated the research interest of many scholars.So far,ZnO materials have been widely used in semiconductor devices,photocatalysis,antibacterial,medical and health fields.It is well known that the properties of materials are related to the composition,structure,particle size and surface morphology of materials.In this paper,graphite phase carbon nitride（g-C₃N₄）materials were introduced to modify and modify ZnO from zinc oxide with different morphologies,and the properties of the materials were investigated.The work of this paper is carried out from the following four aspects:1.Multi-morphology nano-ZnO materials were prepared by precipitation method.Sodium lignosulfonate（CMN）was used as a structure-directing agent,zinc acetate（Zn AC）and sodium hydroxide（Na OH）were used as raw materials.The effects of CMN dosage,Na OH concentration,calcination temperature and calcination time on the purity and morphology of the prepared nano-ZnO were investigated by controlling variable method.The experimental results show that the optimum conditions for the preparation process are as follows:the amount of CMN is 0.33 g/m L,the amount of Zn AC is 0.33 g/m L,the molar concentration of Na OH is 4 mol/L,the calcination temperature is 450℃,and the calcination time is 2 h.2.The antibacterial properties of multi-morphology nano-ZnO were evaluated by microbial culture experiments.The results of the inhibition zone experiment showed that the nano-ZnO prepared under the optimal process conditions had a good inhibitory effect on Bacillus subtilis.The comparative determination of the growth curve showed that the nano-ZnO added to the medium could effectively kill and inhibit the growth of bacteria with the migration of time.3.The monodisperse spherical ZnO was prepared by two-step method,and the photocatalytic properties of spherical,flower and rod ZnO were studied.The results of photocatalytic degradation experiments show that spherical ZnO can achieve full degradation;the degradation rate of flower-like ZnO was 86.6%,and the degradation rate of rod-like ZnO was 71.8%.The mechanism experimental results show that the performance of ZnO photocatalytic system comes from the combined action of·OH,O₂^-·and h⁺.The results of photocatalytic stability experiments showed that the removal rate of Rh B was still above 87%after 6 cycles.The spherical ZnO/g-C₃N₄gel was prepared by one-pot method to improve the photocatalytic properties of ZnO.The photocatalytic degradation experiment confirmed the excellent removal effect of spherical ZnO/g-C₃N₄gel on organic dyes and antibiotics,and the photocatalytic activity of the material was stable.The mechanism experimental results show that the excellent performance of ZnO/g-C₃N₄gel photocatalytic system comes from the combined action of·OH,O^2-·,h⁺and ¹O₂.