Preparation of Nanocrystalline TiO_2 by Sol-Gel-Method at Room Temperature

Nanocrystalline titania(TiO2) particles were obtained at room temperature by a modified sol-gel method starting from a solution with large amount of water. The nanocrystalline TiO2 particles prepared with large amount of water at room temperature were characterized by IR, TEM and XRD. Comparing with conventional sol-gel method, the present system offers quick and complete hydrolysis of titanium precursor before polycondensation, thus resulting in [TiO6] units, and the formation of nanocrystalline TiO2 particles with an average grain size of 3.5 nm. Moreover, the as-prepared nanocrystalline TiO2 powders exhibit a better photocatalytic activity than both of the powders prepared by conventional sol-gel method and the commercial photocatalyst Degussa P25.