Efficient Catalytic Fixation Nitrogen Activity Under Visible Light by Molybdenum Doped Mesoporous TiO 2

An efficient photocatalyst capable of forming oxygen defects on the surface of mesoporous TiO 2 was obtained via doping molybdenum ions which can obviously broaden the absorption range of TiO 2 under visible light and reduce the recombination rate of photogenerated electron–hole pairs. The surface oxygen defects (Vo) introduced by metal molybdenum doping will adsorb and activate target molecules on the semiconductor surface. The effect of Vo content, modulated by Mo ions doping, on the photocatalytic NH 3 production rates of the as-obtained samples was investigated. The optimal photocatalytic NH 3 generation rate of Mo-doped TiO 2 could reach 183.02 μmol·g −1 ·h −1 under visible light. PL and photoelectrochemical tests results demonstrated that Mo dopants could promote photogenerated carrier’s separation and restrain the recombination of carriers. Furthermore, the photocatalysts also exhibited good stability in the recycling experiments for 5 runs. The enhanced photocatalytic activity is owing to the Vo defect states, created by the Mo ion-doped, which benefits to the N 2 adsorption and reduction at the Ti 4+ activation center during the nitrogen fixation process. Graphic Abstract