Formation of silica nanolayer on titania surface by photocatalytic reaction

Silica nanolayers were formed as adsorbents on anatase-type titania particles immersed in tetraethyl orthosilicate (TEOS) solutions during UV irradiation. The concentration of the basic OH groups on the titania surface increased during the UV irradiation. The basicity promoted hydrolysis and subsequent polymerization of the TEOS on the titania surface on which the silica layers were deposited. The titania particles loading a small amount of the thin silica layers exhibited a higher photocatalytic activity for organic molecule degradation and photofuel cell performance than the original titania. The silica-modified titania particles efficiently adsorbed, then degraded the molecules on the surface. Therefore, the photocatalyzed surface modification in this study was significantly useful to activate the titania surface.