Influence of Mn2+ and Mo6+ dopants on the phase transformations of TiO2 lattice and its photo catalytic activity under solar illumination

TiO2 was doped with p-type (Mn2+) and n-type (Mo6+) dopants and their photo catalytic activity was studied under solar light choosing the degradation reaction of amaranth. The photo catalysts were characterized by various analytical techniques. XRD revealed only anatase phase for Mo6+-TiO2 and mixed phase for Mn2+-TiO2 samples. Mo6+-TiO2 sample showed largest red shift in the band gap owing to its higher electronegativity. Mn2+-TiO2 (0.06%) showed better activity due to the synergestic effect of the mixed phase. Further half filled electronic configuration of Mn2+ traps the charge carriers shallowly and detraps the same to the surface of the catalyst which accelerates the interfacial charge transfer processes. (c) 2008 Elsevier B.V. All rights reserved.