Preparation of Titanium Oxide Photocatalysts Anchored on Porous Silica Glass by a Metal Ion-Implantation Method and Their Photocatalytic Reactivities for the Degradation of 2-Propanol Diluted in Water

Highly dispersed titanium oxide photocatalysts anchored onto transparent plates of porous silica glass were successfully prepared by metal ion implantation, and their photocatalytic reactivity for the liquid-phase photocatalytic degradation of an aqueous 2-propanol solution was compared with that in an aqueous TiO2 dispersion. The titanium ions implanted into the porous silica glass are found to be present on the surface layer as isolated tetrahedral titanium oxide moieties by diffuse reflectance absorption, SIMS, XPS, and XAFS analyses. The specific photocatalytic reactivity of the anchored catalyst was much higher than that for TiO2 powder, which may be attributed to the tetrahedrally coordinated titanium oxide moieties. Metal ion implantation is one of the novel and useful techniques to prepare highly efficient photocatalysts on glass plates.