Visible light responsive iron-doped TiO2 (Fe3+/TiO2-IL) was synthesized by sol-gel method using 1-vinyl-3-propylimidazolium iodide (VPIM+I-) as a reaction medium. VPIM+I- not only made the morphological and structural changes of Fe3+/TiO2-IL, but also extended its absorption edge to the visible light region. The photocatalytic activity of Fe3+/TiO2-IL was tested in the degradation of 2-nitrophenol under simulated solar light irradiation. The photocatalytic activity of Fe3+/TiO2-IL was higher than the samples prepared in the reaction medium without VPIM+I-. Moreover, the effect of pH and H2O2 on the photocatalytic activity of Fe3+/TiO2-IL was also investigated. Fe3+/TiO2-IL showed high photocatalytic activity in acidic environment, and H2O2 had a dual effect on the photocatalytic activity Fe3+/TiO2-IL. (c) 2012 Elsevier B.V. All rights reserved.