Carbon-coated Magneli phases TinO2n-1 were prepared by a simple heat treatment of the powder mixture of rutile-type TiO2 with poly(vinyl alcohol) PVA at 1100 degrees C in inert atmosphere. The lower TiO2/PVA ratio in the mixture resulted in TinO2n-1 with the lower n-value. Carbon-coated TinO2n-1 phases thus prepared showed photocatalytic activity under visible light. The TinO2n-1 phases with n-vales of 2 and 3 had higher activity under visible light than those with n-values of more than 4. Carbon coated on the particles was found to reduce the matrix rutile-type TiO2 to Magneli phases TinO2n-1 during the heat treatment, in addition to suppress the sintering and grain growth of TinO2n-1 particles and to enhance the photocatalytic activity by increasing local concentration of the pollutant due to its adsorptivity. (C) 2008 Elsevier B.V. All rights reserved.