Uranyl Photocatalyzed Polystyrene Oxidative Degradation under Visible Light in a Green Solvent

Polystyrene (PS) provides a huge convenience and promotes economic and social development. However, difficulties in recycling and degradation of PS make PS waste hazardous to the environment and organisms. In recent years, up-recycling of PS, which turns PS to oxygenated monomer products with added value such as benzoic acid, has attracted much attention since it turns waste into treasure and offers a reference for pollution treatment. Considering the solubility of PS and the character of a solvent such as toxicity, volatility, and explosiveness, herein, we described a mild, green, and effective PS degradation under uranyl photocatalysis. The main high-value upgrading product, benzoic acid, was obtained. Mechanism of degradation was discussed based on multianalysis such as gas chromatography/mass spectrometry (GC-MS), gel permeation chromatography (GPC), infrared spectrum (IR), isotopic labeling, simulations of small units, and so on. In addition, the successful application on a 20-g scale under sunlight demonstrated the potential of this method for utilizing solar energy for PS degradation.