Enhanced visible light photocatalytic activity of novel Pt/C-doped TiO2/PtCl4 three-component nanojunction system for degradation of toluene in air.

C-doped TiO(2) nanoparticles prepared by partial oxidation of TiC were modified with Pt species by impregnation-calcination method in order to enhance the visible light photocatalytic activity. The physicochemical properties of as-prepared samples were characterized by various techniques in detail. The results indicated that a novel Pt/C-doped TiO(2)/PtCl(4) three-component nanojunction system was formed, where C-doped TiO(2) and PtCl(4) behaved as two visible light responsive components, and Pt metal as electron-transfer system. The three-component nanojunctioned photocatalyst system exhibited six times higher visible light activity than that of the pristine C-doped TiO(2) in degradation of toluene in air. The dramatically enhanced activity can be attributed to the increased utilization of visible light, the enhanced charge carrier separation and transfer process. Further more, the band structure and photocatalysis mechanism over the three-component nanojunction system was proposed and discussed. This work may provide new insights into the design of novel multi-component photocatalyst system with efficient visible light activity.