PREPARATION AND CHARACTERIZATION OF NANOCRYSTALLINE TiO2 FILM BY ULTRAVIOLET IRRADIATION INDUCED SOL-GEL METHOD

摘要

High photocactive nanocrystalline TiO2 film was prepared by using sol-gel method through ultraviolet irradiation duration the form stage of nuclei. The TiO2 film with photocatalysis was characterized with SEM, XRD and FT-IR. The photoactivity of the TiO2 film as photocatalyst was evaluated by degradation of methylene blue as model objection. It was showed that the remnant organic solvent and organic groups were removed mostly by the induction of ultraviolet irradiation. Simultaneously, the TiO2 on the substrate converted to anatase from amorphous in relative low temperature which could effective avoid the conglomeration. The photocatalysis of the TiO2 film was higher than that of conventional furnace treatment film. It was demonstrated that the form of nuclei were faster than their growth because ultraviolet light afforded sufficient energy as soon as the hydrolyzation occurred, so the crystal size of TiO2 on substrate was finer and narrower distributing. In the formation stage of framework, ultraviolet irradiation induced gel network rearrangement,resulted in Ti-O-Ti bond broke off and the active sites of Ti 3+ ions were formed on the surface of TiO2. The photoactivity of the prepared film was evaluated by degradation of methylene blue. It was showed that ultraviolet irradiation induced sol-gel method is an effective method to enhance the photocatalysis of TiO2 film.