Preparation of novel titania photocatalysts with high activity

New anatase photocatalysts have been prepared by a hydrothermal technique. The powders have been shown to have a high photocatalytic activity, which i s believed to be derived from their high crystallinity and phase purity res ulting in fewer defects that can allow pre-emptive recombination of the fre e electron and positive hole. Bi-phasic particles containing both the anata se and brookite phases have also been prepared, but these have much lower p hotocatalytic activity. (C) 2001 Kluwer Academic Publishers.