A Study Of Forming Mechanism And Properties Of Doped-TiO₂ Thin Films

Titanium dioxide has been studied extensively as its special physicochemical and phocatalytic properties.But the research,development and application of TiO₂ photoca-talyst are faced with some problems that are in need of immediate settlement:the immobilization methods of TiO₂ photocatalyst,the modifided TiO₂ photocatalyst by doped,the preperation technology of TiO₂ photocatalyst.Our researches mainly resolve these problems.The TiO₂ thin films were deposited on glass substrates by sol-gel method.And the surface structural shape,surface feature and spectual property have been researched by such physicochemical methods as SEM, XRD and UV-Vis.The photocatalytic activity has been characterization by the photo-decomposition of methyl orange,and their photocatalytic performance has been tested in terms of the rising temprature speed,calcining temprature,calcining time and the film thickness etc,and fixed the best preparation process.The research showed that when the molar pecent between T(OC₄H₉ⁿ)a:C₂H₅OH: H₂O:DEA is1:23.5:3.7:1 and the ageing temprature is 40℃we can get the stable collidal.When the film under calcining temprature 500℃for 2h,the TiO₂ thin films were firmly deposited on glass substrates and the crystal type of the films is anatase.The photocatalytic activity is best when the thin films of five coating cycles.It was found that the photocatalytic activity of TiO₂ thin films was enhanced after CH₃COOH treatment,and doping Fe³⁺into TiO₂ can change the characterisitic of photocatalytic of TiO₂.The experiments of methyl orange degradation showed that the photocatalytic activity had something to do with the molar ration of Fe³⁺and Ti.When the molar ration of Fe³⁺and Ti was 0.25%the photocatalytic activity was best,but when the molar ration of Fe³⁺and Ti was than 0.75%the photocatalytic activity coule be decreased.