Study On The Control Of Phase Transformation And Photocatalytic Properties Of Composite Photocatalysts

Ti-Sn composite oxides with different amounts of SnO2 were prepared from industrial TiOSO4 by fractional precipitation and coating method respectively. XRD,TEM and BET were used to characterize the crystalline phase,appearance and specific surface area separately, diameters of the particles were calculated from the specific surface area. This paper primarily deals with the effects of SnO2 doping and heat treatment on phase transformation of TiO2 from anatase to rutile. The results show that doping of SnO2 favored formation of the rutile phase and the amounts of SnO2 do influence the ratio of anatase to rutile.The influence of Ti-Sn composite oxides with different amounts of rutile phase and SnO2 doping on the photocatalytic degradation of methyl orange has been studied. The highest decoloration of methyl orange (η4h=88.4%) can be achieved using fractional precipitation prepared nanocrystlline particles (22.75% rutile phase) which was doped with 16% SnO2 and calcined under 600℃ for 30min.TiO2 thin films were prepared from sol-gel process. TiOSO4 and Ti(OBu)4 were used as precursors while glass fiber cloth and glass plates were used as substrates respectively. The results show that TiO2 thin films demonstrate better photocatalytic properties than supported TiO2 compound powders. The thin films prepared from Ti(OBu)4 demonstrate better properties than the other one. After degradation for 4 hours, the decoloration of methyl orange solution was 92.1%.