Coupling Plastic Upgrading and Photocatalysis: Catalytic Mechanisms and Design Principles

Converting plastic wastes into valuable chemicals and fuels provides an attractive alternative solution. However, current catalytic technologies often require rigorous conditions such as high temperature, high pressure, and caustic bases, resulting in high energy costs and secondary environmental contamination. Recently, integrating plastic upgrading with photocatalysis into one reaction system has been proven to be an effective approach that can sufficiently utilize photogenerated electrons and holes to achieve sustainable economic development. In this review, we summarize current advances in coupling plastic upgrading and photocatalysis by focusing on the catalyst selection, design principles of these integrated systems, including photoreforming H2 evolution, photocoupling CO2 reduction, and photo-oxidation, and the underlying catalytic mechanisms, including holes and reactive oxygen species mechanisms. We also assess the economic feasibility and environmental impact of these integrated technologies based on techno-economic analysis and life cycle assessment. The ongoing challenges and future research directions in this field are critically discussed. We believe that this review will inspire more creativity in designing such win–win coupled photoredox reaction systems.