Interfacial Structure of Ta2O5/Si Film and Photoactivity

Tantalum oxide (Ta2O5) thin film photocatalysts were prepared on single crystal Si(110) substrates via sol-gel and spin coating methods. Ta2O5 crystallinity was improved, and the crystal size became larger with the increase of heat-treating temperature. The interface diffusion and reaction of the film were studied by using Auger electron spectroscopy (AES) depth profile and line shape analysis. Diffusion was dominant at the interface layer when the calcination temperature was below 700 °C. When the temperature reached 800 °C, both interface diffusion and reaction occurred. The photocatalytic activity was studied using aqueous salicylic acid as a degradation probe molecule under UV-light irradiation. It was found that Ta2O5/Si film showed a photocatalytic activity similar to that of TiO2/Si film.