Fundamentals and challenges for indirect and direct photocatalytic conversion of plastic wastes into valuable fuels

Abstract

Nowadays, plastic wastes have seriously endangered human health and ecological safety. Recycling plastics is a promising approach 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 plastic conversion are divided into two categories: direct and indirect photoconversion. We summarize in detail the photocatalytic small organic molecules conversion from polyethylene terephthalate, polylactic acid and polyethylene through the alkaline-assistant and hydrothermal pretreatments. Then, we overview the effective strategies of direct photoconverting polyethylene, polylactic acid and polyvinyl chloride into chemicals via the two-step process, amination strategy, and single reactive oxygen species-assistant strategy. Finally, we present some outlook on the current challenges and propose some potential solutions in the future. (Figure presented.)