▎ 摘　　要

Enhanced photocatalytic activity of the graphene-hybridized TiO2 composite by nitrogen anion under the visible light has been reported, where we presented the synthesis of nitrogen-doped graphene/TiO2 (graphene-N/TiO2-xNx) by a hydrothermal method in a solution containing urea. A hybrid photocatalyst consisting of TiO2, nitrogen anion and graphene sheets with excellent solar light-induced photoactivity was demonstrated as compared with graphene/TiO2 and graphene/TiO2-xMx composite. The photocatalytic activity of graphene/TiO2 composite in the presence of nitrogen anion was evaluated by degradation of benzoic acid under solar light, which showed a remarkable enhancing effect. This work determined that nitrogen anion not only expands the visible light absorption region of TiO2, but also accelerates the electron transfer in the graphene network as a highway. (C) 2012 Elsevier B.V. All rights reserved.