Enhanced photodegradability of PVC plastics film by codoping nano-graphite and TiO_2

摘要

A novel photodegradable Nano-G/TiO_2/PVC composite film was prepared by codoping nano-graphite (Nano-G) and TiO_2 photocatalyst in Polyvinyl chloride (PVC) plastic. The Characterization tests were performed by using ultraviolet-visible spectroscopy (UV-vis), infrared spectroscopy (FT-IR), scanning electron microscopy (SEM), gel permeation chromatography (GPC) and physical and mechanical properties. Compared with TiO_2/PVC, Nano-G/PVC and PVC film, the Nano-G/TiO_2/PVC composite film showed higher photodegradability. The weight loss rates of Nano-G/PVC (Nano-G 1 wt%), TiO_2/PVC (TiO_2 1 wt%) and Nano-G/TiO_2/PVC (Nano-G 1 wt%, TiO_2 1 wt%) films after the UV irradiation for 30 h were 7.68%, 8.94% and 17.24%, respectively, while that of PVC was only 2.12%. For the Nano-G/TiO_2/PVC composite film, the optimal doping amount of nano-graphite is 1 wt%. The decline rates of Mw and Mn of Nano-G/TiO_2/PVC (Nano-G 1 wt%, TiO_2 1 wt%) composite film were 12.93% and 61.97%, respectively, which were much higher than that of PVC. Nano-graphite can effectively improve the migration and separation of TiO_2 photogenerated electrons, improving the photodegradation rate of PVC. The mechanism of the Nano-G/TiO_2/PVC composite film photocatalytic degradation was proposed. The photocatalytic technology is a feasible and effective way to solve "white pollution".