Enhanced Visible Light Photocatalytic Activity of V_2O_5 Cluster Modified N-Doped TiO_2 for Degradation of Toluene in Air

摘要

V_2O_5 cluster-modified N-doped TiO_2 (N-TiO_2/V_2O_5) nanocomposites photocatalyst was prepared by a facile impregnation-calcination method. The effects of V_2O_5 cluster loading content on visible light photocatalytic activity of the as-prepared samples were investigated for degradation of toluene in air. The results showed that the visible light activity of N-doped TiO_2 was significantly enhanced by loading V_2O_5 clusters. The optimal V_2O_5 loading content was found to be 0.5 wt.%, reaching a removal ratio of 52.4% and a rate constant of 0.027 min~(-1), far exceeding that of unmodified N-doped TiO_2. The enhanced activity is due to the deposition of V_2O_5 clusters on the surface of N-doped TiO_2. The conduction band (CB) potential of V_2O_5 (0.48 eV) is lower than the CB level of N-doped TiO_2 (-0.19 V), which favors the photogenerated electron transfer from CB of N-doped TiO_2 to V_2O_5 clusters. This function of V_2O_5 clusters helps promote the transfer and separation of photogenerated electrons and holes. The present work not only displays a feasible route for the utilization of low cost V_2O_5 clusters as a substitute for noble metals in enhancing the photocatalysis but also demonstrates a facile method for preparation of highly active composite photocatalyst for large-scale applications.