High photocatalytic degradation activity of the polyvinyl chloride (PVC)-vitamin C (VC)-TiO2 nano-composite film

A novel photodegradable polyvinyl chloride (PVC)-vitamin C (VC)-TiO2 nano-composite film was prepared by embedding VC modified nano-TiO2 photocatalyst into the commercial PVC plastic. The solid-phase photocatalytic degradation behavior of PVC-VC-TiO2 nano-composite film under UV light irradiation was investigated and compared with those of the PVC-TiO2 film and the pure PVC film, with the aid of UV-Vis spectroscopy, scanning electron microscopy (SEM), weight loss monitoring, and X-ray diffraction spectra (XRD). The results show that PVC-VC-TiO2 nano-composite film has a high photocatalytic activity: the photocatalytic degradation rate of it is two times higher than that of PVC-TiO2 film and fifteen times higher than that of pure PVC film. The optimal mass ratio of VC to TiO2 is found to be 0.5. The mechanism of enhancing photocatalytic activity is attributed to the formation of a Ti-IV-VC charge-transfer complex with five-member chelate ring structure and a rapid photogenerated charge separation is thus achieved. (C) 2010 Elsevier B.V. All rights reserved.