Property And Preparation Of Self-cleaning Nano-sized Tio₂Film Ceramic

With the progress of our society and the advancement of living standard, People’sconsciousness of environmental protection is gradually strengthened. Especially in recentyears, the ravages of the SARS virus and the avian influenza make people to know that thepurification of home environment, cleaning outside air and protecting water resources arevery important. So, people put forward higher request to the traditional building and sanitaryproducts, mainly in properties such as the stain-proofing, self-cleaning etc. TiO₂nanopowderpossesses high photocatalysis activity, superhydrophilic and chemical stability, and it hasbeen applied in the fields of environmental protection, indoor air cleaning and self-cleaningcoating etc., and has been one of the hot researches in photoehemistry and photocatalysisfields.In this thesis, nano-TiO₂, TiO₂-ZnTiO₃and TiO₂-Zn2TiO₄sols were prepared fromTi（OC₄H₉）4as raw material in alcohol-water system by sol-gel process, and self-cleaningceramics of the nano-TiO₂, TiO₂-ZnTiO₃and TiO₂-Zn2TiO₄films were fabricated withnormal glazed ceramic as substrate by the direct coating method. The samples werecharacterized with modern testing means, such as the thermal analysis （TG-DSC）, fouriertransform infrared spectrometer （FT-IR）, X-ray diffraction （XRD）, atomic force microscope（AFM） and scanning electron microscopy （SEM） etc. to determine their formation process,phase, particle size and morphology.The preparation of single composition of TiO₂sol and its thin film was researched in thisthesis. The result showed that the amount of CH₃COOH had a great influence on the stabilityof TiO₂sol. When CH₃COOH: Ti（OC4H9）4moral ratio for13:1, the stability of TiO₂solwas better and the pH value was2.4. The heat treatment temperature primarily influenced thecrystalline structure of TiO₂. It was a kind of amorphous when the heat treatment temperaturebelow300℃and it could generate anatase TiO₂at400℃. At600℃, the anatase TiO₂andthe rutile TiO₂coexisted, and the rutile TiO₂is about14%, whose hydrophilicity andphotocatalytic activity were the best. The influences including the light source type, UVirradiation time and thickness on the property of film were also discussed.According to the preparation parameters of TiO₂sol, the TiO₂-ZnTiO₃/TiO₂-Zn2TiO₄nanocomposite films were prepared and researched, the results showed that the crystaltransition temperature from anatase to rutile was increased from600℃to800℃due to Zndoping. It means that the Zn doping can restrain anatase to rutile transition. At the same time,the XRD intensity of anatase TiO₂decreased and its peaks broadened with the increase of the Zn doping content, which indicated the Zn doping can inhibit the TiO₂crystals from growingup.In addition, the related performances of single composition nano-TiO₂thin film,TiO₂-ZnTiO₃and TiO₂-Zn2TiO₄nano-composite films were examined in this thesis, theperformances included superhydrophilic and its influencing factors. Meanwhile, thephotocatalysis degradation properties of organic matter for the films were researched with the5wt%of methylene blue solution as the target degradation organic matter. The experimentalresults showed that for different component films, TiO₂-ZnTiO₃film properties were betterthan that of TiO₂-Zn2TiO₄film, and TiO₂-Zn2TiO₄film properties were superior to that ofsingle component TiO₂film. That is to say, the performance of compound film is superior tothat of single film, and the perovskite ZnTiO₃can effectively improve superhydrophilic andphotocatalysis activity of TiO₂film.