Beyond mechanical recycling: artificial photosynthesis enables polyester plastic upcycling into valuable chemicals

The accumulation of waste plastics presents a severe environmental challenge. Among plastics, polyester plastics featured with ester-rich backbones are particularly promising for chemical recycling into valuable products. Recently, artificial photosynthesis, one of the well-known chemical methods for plastic disposal, has emerged and been devoted to convert the waste into wealth through partial oxidation of plastic substrates under mild conditions. In this review, we elaborate on various pathways of polyester plastic conversion, including polyester plastic upcycling integrated with water splitting, polyester valorization coupled with CO₂ reduction, and organonitrogen synthesis from polyester. This review begins by discussing the fundamental mechanisms of photoinduced plastic conversion as well as its advantages compared with traditional plastic disposal and biological treatment approaches. We then outline the design principles for the development of high-performance photocatalysts, such as tuning redox potentials, promoting charge separation, enhancing substrate absorption and leveraging photothermal-assisted photocatalysis. Furthermore, we summarize the recent advances in plastic conversion and the underlying mechanisms. In addition, techno-economic assessment and life cycle assessment are used to evaluate the economic viability and environmental impact of solar-driven plastic upcycling, respectively. Finally, future challenges and research perspectives, such as photocatalyst screening, reactor design and the synthesis of multicarbon compounds, are critically discussed. This review presents a blueprint for the development of advanced photocatalysts for polyester plastic conversion, thereby closing the carbon loop for postconsumer polyester plastics.