Immobilization of highly active titanium(IV) oxide particles - A novel strategy of preparation of transparent photocatalytic coatings

Titanium(IV) oxide (TiO2) powders synthesized by HyCOM (hydrothermal crysta llization in organic media) method, which had been proved to exhibit ultra- high photocatalytic activity in several reaction systems, were used as star ting material for fabrication of transparent TiO2 thin films. HyCOM-TiO2 po wders were dispersed in aqueous sol of nitric acid to yield a TiO2 sol stab le for more than 90 days. Transparent TiO2 thin films were successfully pro duced by dip-coating from the TiO2 sol and used for photocatalytic decompos ition of malachite green (MG) in an aqueous sol under aerated conditions. T hese films exhibited much higher rate of MO decomposition compared with tho se prepared from a commercially available TiO2 sol developed for photocatal ytic use (Ishihara STS-01), indicating that the excellent photocatalytic ac tivity of original HyCOM-TiO2 particles was preserved after immobilization on glass substrates by the present method. (C) 2001 Elsevier Science B.V. A ll rights reserved.