Study On Preparation And Application Of Visible-light Response TiO₂ Photocatalysts

In recent years,bacteria,viruses,pathogens and other harmful microorganisms bring many adverse effects to human life;TiO₂material as a new type of environmental protection and antibacterial materials,due to its high efficiency,stability,no pollution and broad applicability of various aspects,has been widely used in people’s lives.This paper first introduces the photocatalytic status of TiO₂ photocatalytic materials,and the current preparation methods and how to improve its photocatalytic performance were introduced,after modification of TiO₂ material is two points;finally,through a series of experiments to explore the mechanism of photocatalytic sterilization of photocatalytic sterilization.The main contents are as follows:1.By solvothermal synthesis of mesoporous TiO₂ microspheres is simple,the carbonate incorporated into mesoporous TiO₂ microspheres by low temperature heat treatment method,modified TiO₂ materials after the light absorption range from UV extended to visible light,the photocatalytic activity has been well improved.Under visible light irradiation,the preparation of carbonate doped TiO₂ microspheres prepared,more than 95% methyl orange can be degraded in 150 min,killing over 71% of Escherichia coli in 160 min.The photocatalytic activity was significantly higher than that of the pure TiO₂ catalyst.2.By in situ precipitation process for the preparation of a series of Ti O₂ / Ag₃PO₄ heterojunction composite.The composite modified visible light absorption enhancement and photogenerated electron hole can be effectively separated,so compared with the TiO₂ and Ag₃PO₄ materials,under the condition of visible light photocatalytic inactivation of Escherichia coli was obviously enhanced.In addition,the composite anti fungus（Fusarium graminearum）on photocatalytic,under the visible light,TiO₂ / Ag₃PO₄ composite material can make the Fusarium graminearum macroconidia survival rate decrease to about 2% in 100 min.ESR measurements showed that the hydroxyl radical and superoxide radical.The base plays a major role in the photocatalytic bactericidal activity in the experiment.Research on photocatalytic mechanism demonstrated by fluorescence staining: cell wall,reactive oxygen species produced by photocatalytic destruction of fungus spore membrane,leading to cell death.The results of this study for photocatalytic materials for the prevention and control of agricultural plant pathogens to provide a great help.