Structural study of SiO2-TiO2 sol-gel films by X-ray absorption and photoemission spectroscopies

摘要

Sol-gel derived silica-titania films, containing 0-30 mol% TiO2, were prepared by spin-coating and heat treated at temperatures up to 900 degrees C. They were studied by X-ray photoemission (XPS) and near-edge X-ray absorption fine structure (NEXAFS) spectroscopy. The number of oxygen atoms in Si-O-Ti and Ti-O-Ti bonds was found to vary from 0 to 25% as the TiO2, content increased from 0-30 mol%. The fraction of these oxygen atoms also increased with heat-treatment temperature, to 700 degrees C, for the 80SiO(2)-20TiO(2) base composition, showing a continuous increase in both Si-O-Ti hetero-condensation and Ti-O-Ti home-condensation bonding sequences. (C) 1997 Elsevier Science B.V.