A new kind of binary TiO2-Ti2O3 photocatalyst was successfully prepared by a simple photo-assisted sol-gel method. The as-prepared catalyst exhibited remarkable photocatalytic activity in decomposition of many organic dye pollutants, including sulforhodamine B (SRB), eosin, erythrosin B, and rhodamine B (RB) under visible light illumination. The ESR spectrum clearly showed that OHcenter dot radicals were formed. These acted as an active species in the decomposition of organic dyes over as-prepared photocatalyst suspensions under visible light illumination. (c) 2005 Elsevier B.V. All rights reserved.