Photocatalysis as a tool for upcycling of polymers

Valorization of waste polymers constitutes an attractive solution for alleviating relevant environmental pollution. Among various strategies for polymer upcycling, photocatalysis has emerged as an environmentally-benign and effective tool for converting polymers into newly functionalized polymers or value-added chemicals. Notable features include mild reaction conditions, high selectivity, and complementary upcycling modes to conventional two-electron pathways. In this review, recent progress on homogeneous photocatalytic modification and degradation of polymers has been summarized based on the types of broken bonds in the starting polymers. The typical mechanism for various photocatalytic systems is elucidated. Finally, the future outlook of this field is also presented. It is anticipated this review will stimulate further development of this newly emerging but certainly promising research area.