BACKGROUND: Semiconductor TiO2 has been investigated extensively due to its chemical stability, nontoxicity and inexpensiveness. However, the wide band gap of anatase TiO2 (about 3.2 eV) only allows it to absorb UV light. TiO2 nanoparticles modified by conditional conjugated polymers show excellent photocatalytic activity under visible light. However, these conjugated polymers are not only expensive, but also difficult to process. Polyvinyl chloride (PVC) was heat-treated at high temperature to remove HCl and a C?C conjugated chain structure was obtained. When TiO2 nanoparticles were dispersed into the conjugated polymer film derived from PVC, this composites film exhibited high visible light photocatalytic activity. RESULTS: The photocatalytic activity of TiO2/heat-treated PVC (HTPVC) film was investigated by degrading Rhodamine B (RhB) under visible light irradiation. The photodegradation of RhB follows apparent first-order kinetics. The rate constants of RhB photodegradation in the presence of the TiO2/HTPVC films with different mass content of TiO2 are 1656 and 414 times that obtained in the presence of the pure HTPVC and TiO2/polymethyl methacrylate (PMMA) composite film, respectively. The TiO2/HTPVC film showed excellent photocatalytic activity and stability after 10 cycles under visible light irradiation. CONCLUSION: TiO2/HTPVC film exhibits high visible light photocatalytic activity and stability. Copyright (C) 2012 Society of Chemical Industry