| Nanostructured TiO2 photocatalytic antibacterial ceramics have received considerable interest because of their advantages, such as wide antibacterial pedigree, sterilization and mineralization bacteria remains, good antimicrobial durability, no toxic to human body, no harm to environment. They can be used as the substitute for the conventional Ag-series antibacterial cermics, although the low photocatalytic activity of TiO2 antibacterial agents at high temperature has limited their application. In the thesis, to improve the heat-durability and photocatalytic activity of TiO2 antibacterial agents, TiO2 composite nanocrystals have been prepared by a nanocomposite method using Al2O3, SO42-, ZnO, SnO2, La2O3 as heterogeneous composite agents. The influences of heterogeneous composite agents on TiO2 phase transition, particle growth and optical absorbance in UV and visible region, antibacterial effect are investigated. The composite structures are studied, and the structure model of uniform surface adsorption of heterogeneous composite agents on the surface of TiO2 nanocrystal and the mechanism of chemical bonding between construction units of TiO2 and that of heterogeneous composite agents are proposed . The main results are as follows:Solution-based coprecipitation method is simple and effective to obtain the composite structure, i.e. the structure of heterogeneous composite agents well dispersed on TiO2 surface. In the synthesis, the properties of TiO2 nanocrystal at high temperature are influenced by many synthetic factors, such as the reaction mode, reactants concentration, the dehydration approach of reaction product, reaction temperature, species of precipitators, reactants solution agitation rate, etc.The crystal structure of TiO2 nanocrystal compounded by Al2O3 are anatase after calcined at 700-900℃, Moreover, mixed crystalline structures of TiO2 are formed at 950-1050℃, and the proportion of anatase and rutile can be adjusted from 80:20 to...
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