Water splitting on Rhodamine-B dye sensitized Co-doped TiO2 catalyst under visible light

An effective rhodamine B (Rh B) dye sensitized Co doped TiO2 (Co/TiO2) materials was prepared by simple physical absorption for photocatalytic water splitting under visible light. The prepared Rh B-Co/TiO2 materials showed a strong absorbance edge band in the range of 450-600 nm (max. absorbance at 550 nm) and estimated a moderate band gap of 2.58 eV, which lowered than that of Co/TiO2 (2.75 eV). Rh B-Co/TiO2 catalysts showed the high activity towards photocatalytic water splitting under visible light irradiation. The reaction with Rh B-Co/TiO2 catalysts achieved a nearly stoichiometic evolution of H-2 and O-2 evolution of similar to 227.3 mu mol/g-catal/h and similar to 98.9 mu mol/g-catal/h, respectively, which is 6 times higher than that of H-2 evolution (similar to 37.67 mu mol/g-catal/h) over Co/TiO2 catalysts. The enhanced water splitting reaction may be facilitated by the absorbed Rh B near to Co atom. This synergic effect between the Rh B and Co is crucial to the water splitting reaction. (C) 2011 Elsevier B.V. All rights reserved.