A New Electrochemical Method to Prepare Mesoporous Titanium(IV) Oxide Photocatalyst Fixed on Alumite Substrate

A TiO₂ film was deposited onto alumite using an electrochemical technique, where the initial electrodeposition was carried out by ac electrolysis in (NH₄)₂[TiO(C₂O₄)₂] solution, followed by pulse electrolysis in TiCl₃. This is a new method to prepare a mesoporous TiO₂ photocatalyst film consisting of nanosized particles and to directly fix them onto the alumite substrate (Al/Al₂O₃). The sizes of the TiO₂ particles in the prepared film were about 5 nm, and they consisted of mixtures of the anatase, rutile, and amorphous phases. This film had a high catalytic activity for the decomposition of acetaldehyde even under fluorescent lamp illumination. Moreover, the preparation cost is very low compared with other methods. Therefore, the prepared Al/Al₂O₃/ TiO₂ plate is very useful for the practical photodecomposition of chemical contaminants in the atmosphere. The mechanisms of the TiO₂ deposition and the photocatalysis are discussed.