Sonophotocatalytic reaction is a photocatalytic reaction with ultrasonic ir
radiation or the simultaneous irradiation of ultrasound and light with a ph
otocatalyst. The possibility of the effect of hybrid of sonochemical and ph
otocatalytic reactions was examined. Liquid water was hardly decomposed to
H-2 and O-2 by photocatalysis or sonolysis, independently. In order to deco
mpose water, powdered TiO2 photocatalyst suspended in distilled water shoul
d be simultaneously irradiated by light and ultrasound. This sonophotocatal
ytic reaction was effective on the decomposition of water to H-2 and O-2. (
C) 2001 Elsevier Science B.V. All rights reserved.