Photocatalytic activity enhancement in doped titanium dioxide by crystal defects

Abstract

Visible light sensitive Fe3+ and Ce4+ co-doped nano TiO2 photocatalyst has been prepared by a modified aqueous sol–gel method and the activity has been measured in terms of degradation of MB dye. Both dopants shifted the absorption profile of TiO2 to the visible region and improved activity. Fe3+ ions trapped the charge carriers due to the stable electronic configuration and improved their separation. Ce4+ ions, which were mainly located at the grain boundaries, cause dislocations by bending the valence and conduction bands of TiO2 and prevent the recombination of photoexcited electrons and holes. The co-doped TiO2 compositions exhibited higher photocatalytic activity than that of pure titania and commercially available Degussa P25 under visible light by utilising the individual and synergistic contributions of Fe3+ and Ce4+ dopants, respectively