《Sci. China Chem.》: Fundamentals and Challenges for Indirect and Direct Photocatalytic Conversion of Plastic Wastes into Valuable Fuels

Qinyuan Hu,⁺ Jiawei Xie,⁺ Dongpo He,⁺ Zhixing Zhang, Jinyu Ding, Mengqian Li, Wenya Fan, Piming Ma* & Xingchen Jiao*

Nowadays, plastic wastes have seriously endangered human health and ecological safety. Recycling plastics is a promising ap-proach to achieve multiple uses of carbon resources. In this review, photocatalysis is introduced for the conversion of plastics into various valuable chemicals. The state-of-the-art photocatalytic techniques for plastics conversion are divided into two categories of direct and indirect photoconversion. We summarize in detail the photocatalytic small organic molecules conversion from polyeth-ylene terephthalate (PET), polylactic acid (PLA) and polyethylene (PE) through the alkaline-assistant and hydrothermal pretreat-ments. Then, we overview the effective strategies of direct photoconverting PE, PLA and polyvinyl chloride into chemicals via the two-step process, amination strategy, and single reactive oxygen species-assistant strategy. Finally, we present some outlooks of the current challenges and propose some potential solutions in the future.

Figure 1. Scheme of indirect and direct photocatalytic conversion of various waste plastics into fuels.