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 H2 and O2 evolution of ∼227.3 μmol/g-catal/h and ∼98.9 μmol/g-catal/h, respectively, which is 6 times higher than that of H2 evolution (∼37.67 μmol/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.

Figure optionsDownload as PowerPoint slideHighlights
► Rhodamine B (Rh B) dye sensitized Co doped TiO2 (Co/TiO2) materials was prepared for photocatalytic water splitting under visible light.
► Rh B-Co/TiO2 obtains a strong absorbance edge band at max. absorbance 550 nm with lower band gap of 2.58 eV.
► Water splitting with Rh B-Co/TiO2 catalysts achieved nearly stoichiometric evolution of H2 and O2 evolution of ∼227.3 μmol/g-catal/h and ∼98.9 μmol/g-catal/h.
► 6 times higher H2 evolution obtains as compared with Co/TiO2 catalysts.