Structures and photocatalytic performance of N-doped TiO2 modified by platinum chloride(PtClx/N-TiO2) was investigated. It was found that the PtClx/N-TiO2 forms anatase structure of TiO2 involving nitrogen, chloride species and platinum ions (+IV) as major species, and it exhibits higher photocatalytic activity than either N-TiO2 or PtClx/TiO2 for the decomposition of acetic acid or acetaldehyde in aqueous solutions under visible light irradiation (lambda > 420 nm). An enhancement of the photocatalytic activity on PtClx/N-TiO2 has been proposed as a Z-scheme mechanism for charge separation between platinum chloride and N-TiO2. (C) 2008 Elsevier B.V. All rights reserved.