Effect of Calcination Temperature on the Photocatalytic Activity of Porous TiO₂ Film

To obtain porous TiO2 film, the precursor sol was prepared by hydrolysis of Ti isopropoxide and then complexed with trehalose dihydrate. The porous TiO2 film was fabricated by dip-coating method on quartz glass substrates using this sol. The TiO2 films were calcined at 500-900 °C. The photocatalytic activities of the films were evaluated by examining decomposition of methylene blue in aqueous solution under UV light irradiation. The photocatalytic activity of the porous TiO2 film showed a different tendency according to the irradiation wavelength of UV light. The activity of the film evaluated under UV light irradiation with a wavelength of 254 nm was not affected a great deal by the clacination temperature. In the case of UV light irradiation with a wavelength of 365 nm, the activity of the film increased with increasing calcination temperature and that of the film calcined at 800 °C was the highest.