Abstract:Using titania nanoparticles (TiO2) with anatase-rutile hybrid crystal type as photo-catalyst, the solid-phase photocatalytic degradation of polystyrene (PS) and its blends with TiO2 (PS/TiO2) after irradiating under 250W metal halide lamp were comparably investigated by the measurements of mass loss, TGA, GC, UV-vis, 1H-NMR and GPC. The results show that the pure PS remains stable even after irradiation for 100 h, while, after irradiation for 40 h, PS/TiO2 suffers polymer chain scission (the relative weight average molecular mass decreases from 3.2×105 to 2.2×105), oxidation (the 1H-NMR detects a chemical shift of H belonging to the hydrogen atom connecting with carbonyl groups), and at last mineralization into CO2 and H2O (in PS/TiO2, the more mass loss, the new small molecule compounds and the more CO2 are monitored). The study demonstrates that, in the solid-phase, TiO2 can promote the degradation of PS via light irradiation. This may provides a new idea for the purification of plastic wastes.