Photocatalytic Degradation of Acetaldehyde on Mesoporous TiO2: Effects of Surface Area and Crystallinity on the Photocatalytic Activity

Abstract

Mesoporous TiO2 powder and films with worm-like channels were synthesized by an evaporation-induced self-assembly approach. The as-prepared samples were calcined at different temperature to investigate the effect of calcined temperature on the mesostructure and the photocatalytic activity. Acetaldehyde photodegradation in gas phase was employed to evaluate the photocatalytic activity of mesoporous TiO2. Results showed that all the calcined powder samples exhibited higher photocatalytic activities than that of Degussa P25. The sample calcined at 400C, which showed higher activity than other samples, possessed a homogeneous pore diameter of about 6.0 nm and an 11.0 nm crystalline anatase pore wall, as well as large surface area of 117 m2/g. It was speculated that two factors of surface area and crystallinity affected the photocatalytic activity of mesoporous TiO2 photocatalyst. The mesoporous TiO2 films fabricated by spin-coating also had high photocatalytic activities.