Nitrogen doped mesoporous TiO2 Was prepared via a modified two-step hydrothermal route. In contrast to undoped mesoporous TiO2, nitrogen doped mesoporous TiO2 has superior photocatalytic activity under both UV and visible light irradiation. Photoluminescence spectra reveal that nitrogen doped mesoporous TiO2 possesses abundant surface states, which can play a vital role in trapping photoinduced carriers as evidenced by photoelectrochemical process and prolonging the lifetime of the carriers. The remarkably enhanced photocatalytic activity in nitrogen doped mesoporous TiO2 is attributed to the generated abundant Surface states. (C) 2009 Elsevier Inc. All rights reserved.