Photocatalytic and Electrocatalytic C–H Functionalization: Sustainable Pathways for Polymer Upcycling

Synthetic polymers serve as cornerstones of modern industry, offering exceptional mechanical strength, chemical inertness, and cost‐effectiveness. The continuous pursuit of advanced materials has expanded polymer diversity through innovative synthetic methodologies. Among them, post‐functionalization is one of the most effective strategies, which employs polymers as the substrate for precision modification. Conventional plastic waste management faces dual challenges of energy loss and environmental pollution, while C–H activation enables chemical upgrading of inert polyolefins into value‐added materials. Recent advances in photo‐ and electrocatalytic C–H functionalization offer sustainable pathways for polymer upcycling. These technologies enable precise molecular transformations under mild reaction conditions, circumventing the energy‐intensive processes and poor selectivity inherent to conventional thermal methods. This review critically analyzes current advancements in photo‐ and electrocatalytic C–H activation strategies for polymer functionalization, while outlining emerging frontiers in redox mediator engineering, catalyst design, and electrophotocatalytic systems. This field promises molecular‐level solutions for plastic pollution, accelerating circular material economies under global carbon neutrality goals.