TiO2 coating films prepared from alkoxy-derived nanocrystalline anatase suspensions

摘要

Nanocrystalline anatase suspensions with various formative ratioof anatase (Af in mass%) were synthesized through hydrolysis andhydrothermal treatment of titanium tetraisopropoxide, and wereused for preparation of coating films. Films were dip-coated onglass plates with a withdrawal speed of 50 cm/min, followed byheating at 500°C for 1h. Crack-free and transparent TiO2 filmscould be prepared from the suspensions with about 85% Af. Howeverbelow about 85% Af, cracks and island texture were observed in thefilms. It was found that the area shrinkage of films proportionallydecreases with increasing Af. The critical thickness for obtainingcrack-free films from the suspension of about 100% Af wasapproximately 1 μm and porosity of the film was about 55%. Thehigh photocatalytic activity of the prepared films wasdemonstrated from oxidation and removal of NO under UV irradiation.