Modification of Pd and Mn on the Surface of TiO2 with Enhanced Photocatalytic Activity for Photoreduction of CO2 into CH4

The novel Pd-and Mn-comodified TiO2 photocatalyst (TiO2 Pd-Mn) was prepared via a simple sol gel method. The introduced Pd and Mn existed as the -O-Pd-O- and O-Mn-O species on the surface of the photo catalyst. The band structure and density of states are studied by theoretical calculations, which is demonstrated by the experimental results. The modification with Pd and Mn ions results in the strong visible response and efficient separation of photogenerated carriers. Thus, the TiO2-Pd-Mn exhibit improved photocatalytic activity compared with pure TiO2, TiO2 Pd, and TiO2-Mn for photoreduction of CO2 and H2O into CH4. It is an effective method on developing the highly active TiO2-based materials by modification with double elements on the surface.