Overall water splitting by sonophotocatalytic reaction: the role of powdered photocatalyst and an attempt to decompose water using a visible-light sensitive photocatalyst

The role of a photocatalyst in the sonophotocatalytic reaction of water was investigated using TiO2 photocatalysts. Based on this investigation, sonop hotocatalytic water splitting using visible light was attempted. BiVO4 is a visible light-sensitive material and this material is one of the candidate s for O-2 evolution photocatalyst. For example, O-2 is evolved from H2O2 so lution by photocatalytic reaction under visible light irradiation. On the o ther hand, Hz is produced together with H2O2 from water by irradiation of u ltrasound. Thus, it is expected to obtain H-2 and O-2 from water when these two reaction systems are combined. Simultaneous irradiation of visible lig ht and ultrasound was tried to perform. As the result, liquid water was dec omposed to H-2 and O-2 continuously and stoichiometrically. (C) 2001 Elsevi er Science B.V. All rights reserved.