Kinetic Investigation of Photocatalytic TiO2 Films Prepared by the Sol-Gel Method and Low Temperature Treatments

Abstract

Films of TiO 2 photocatalyst were fabricated using a sol-gel method and processed with low temperature treatments. The TiO 2 sample films were prepared using the sol-gel solution coated on glass substrates. After drying, the coated films were carried out by different thermal treatments. These treatments, including hot water, water-vapor exposure, and sintering, were applied on fabricating the films to evaluate their effects on the photocatalytic activity of the prepared TiO 2 films. The photocatalytic activity of these sample films were demonstrated by a dye degradation test with lighting of UV wavelength at 385 nm. A first order kinetic equation was utilized to estimate the effects of these thermal treatments on the photocatalytic activity of the treated films. Results show that the photocatalytic activity and surface geometry can be observed quite differently by these thermal treatments. The water-vapor exposure method can greatly improve the photocatalytic abilities of the TiO 2 films, although the adhesion was in ill-condition. However, hot water and sintering treatments can improve the adhesion of the films on the glass substrate. In addition, the surface images of the films were obtained by SEM photos to illuminate the influences of these thermal treatments on the surface geometry.