High photocatalytic degradation activity of the polyvinyl chloride (PVC)-vitamin C (VC)-TiO_2 nano-composite film

摘要

A novel photodegradable polyvinyl chloride (PVC)-vitamin C (VC)-TiO_2 nano-composite film was prepared by embedding VC modified nano-TiO_2 photocatalyst into the commercial PVC plastic. The solid-phase photocatalytic degradation behavior of PVC-VC-TiO_2 nano-composite film under UV light irradiation was investigated and compared with those of the PVC-TiO_2 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-TiO_2 nano-composite film has a high photocatalytic activity; the photocatalytic degradation rate of it is two times higher than that of PVC-TiO_2 film and fifteen times higher than that of pure PVC film. The optimal mass ratio of VC to TiO_2 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.