Simple fabrication of rod-like N-doped TiO_2/Ag with enhanced visible-light photocatalytic activity

摘要

Rod-like N-doped TiO_2/Ag composites were successfully synthesized by a modified sol-gel method, without adding any surfactants. The entire preparation differs from the traditional sol-gel synthesis of TiO_2 that the reaction can get controlled by adjusting the flow speed of water vapor and NH_3. Characterization results show that as-prepared samples were uniform nanorods with an average length of ca. 3 μm and a cross section diameter of ca. 150 nm. The rod-like structure was formed during the annealing process. A possible mechanism was proposed to illustrate the formation of rod-like Ag-N-TiO_2. The degradation of methylene blue performed under visible light with the prepared nanorods as the photocatalyst demonstrated the photocatalytic activities of TiO_2 can be improved by the synergistic effect of N doping and Ag modification. In addition, as-prepared TiO_2-based photocatalyst exhibits a significantly enhanced photo-chemical stability after 5 catalytic cycles mainly due to the rod-like morphology. This indicated that they have some potential value in practical application.