| Abstract: The Nanometer TiO2 thin film was prepared by sol method with titanic acid precursor from industrial TiOSO4 solution. The characters of the sol and the factors affecting sol formation were investigated by ζ electricity potential. The crystalline structure, particle size, appearance shape and photo-catalytic activity were characterized by XRD, SEM, TEM and spectrophotometer. The study show: (1) pH value and HNO3concentration effected importantly on the forming process and stability of the sol. The thermodynamic condition for forming sol is pH=0.5～1.5. The lower the HNO3concentration,the more stable the sol. The ζ electricity potential of the sol, with 5% HNO3as gluing reagent, was up to 48 mV, and shelf life of the sol could more than 10 months. (2) The film, made from the sol and crystallized at 400 ℃, had the characters of anatase structure and crystal size of 18.5 nm by XRD analysis. The SEM imagines show that TiO2 film was with the characteristics of tight surface structure, The TEM imagine showed the mean particle size is about 20 nm. The photo-degrading test data indicate that the photo-degrading rate to methyl orange solution of 20 mg·L-1 was more than 84% in 5 hours. |
