As a consequence, powerful oxidation/reduction methods are required to ensure the complete decolorization and degradation of the organic synthetic dyes and their metabolites present in the waste water effl uents. Over the last two decades, photocatalysis has been the area of rapidly growing interest for the removal organic synthetic dyes from the industrial effl uents, which involves the use of semiconductor particles as photocatalyst for the initiation of the redox chemical reactions on their surfaces [6-9]. When the semiconductor oxide particle is illuminated with the radiation having energy comparable to its band gap energy, it generates highly active oxidizing/reducing sites, which can potentially oxidize/reduce large number of organic wastes. Metal-oxide and metal-sulfi de semiconductors, such as titania (TiO2) [6-9], zinc oxide (ZnO) [10], tin oxide (SnO2) [11], zinc sulfi de (ZnS) [12], and cadmium sulfi de (CdS) [13] have been successfully applied as photocatalyst for the removal of highly toxic and nonbiodegradable pollutants commonly present in air and waste water. Among them, TiO2 is believed to be the most promising one since it is cheaper, environmentally friendly, non-toxic, highly photocatalytically active and stable to chemical and photo-corrosion. However, its effective application as a photocatalyst is hindered due to some of its major limitations. First, TiO2 nanocrystallites trend to aggregate (or agglomerate) into large-sized nanoparticles, which affect its performance as a photocatalyst due to the decreased specifi c surface area. Secondly, it has lower absorption in the visible region, which makes it less effective in using the readily available solar energy. Third, the separation of photocatalyst from the treated effl uent, via traditional sedimentation and coagulation approaches, has been diffi cult and time consuming.