THE SURFACE-STRUCTURE OF TITANIUM-DIOXIDE THIN-FILM PHOTOCATALYST

The surface structure of TiO2 thin film photocatalyst was successfully controlled by the sol-gel method with a polymer doped dip-coating pro cess. The thin films prepared were either transparent or translucent d epending on the molecular weight of the polymer doped. The surface of the transparent thin films looked plain consisting of uniformly aggreg ated nanometer size TiO2 particles, while the translucent thin film wa s formed with cubic-like crystalline TiO2 at a micrometer level, The s pecific surface area of the transparent thin film was almost the same as that of the translucent one. All the thin film photocatalysts had a n anatase structure with similar crystallinity. Both the transparent a nd translucent films showed catalytic activity for NOx elimination fro m air. The activity was almost equal to the commercial photocatalyst P 25. (C) 1997 Elsevier Science B.V.