Heterogeneous photocatalysis provides the means not only for utilizing solar energy but also for new synthetic routes1, 2 and pathways of degradation of industrial wastes. 3 Particulate semiconductors suspended in solution or metal-doped semiconductors2 such as TiO2, CdS, ZnO, Fe2O3, WO3, Pt/TiO2, Ag/TiO2, colloidal TiO2, etc., have attracted the attention of many chemists as several reactions which are inaccessible by other means ...