Preparation of TiO_2 Thin Films with Self-cleaning and Antibacterial Properties by Colloidal Chemical Method

The anatase sol was synthesized by colloidal chemical method and the nanocrystalline TiO2 films were then prepared on glass substrates by the dip-coating method from the anatase sol.XRD,TEM,SEM,AFM and water contact angle were used to characterize the microstructure of TiO2 sol and films.The results showed that the TiO2 sol was anatase with high crystallinity.The TiO2 crystals were needle like and average crystallite size was about 8 nm.The surface of TiO2 flims were smooth and diameter of particles was 86 nm in average.The thickness of three-layer film is approximately 150 nm.Moreover,coating layers had little influence on morphology.The degradation of methylene blue reached 93.6% when the films prepared at ambient temperature were irradiated by UV light for 80 min,and the photocatalytic activity increased as heat treatment temperature raised.The TiO2 films possessed self-cleaning and antibacterial properties,as well as super hydrophilicity.