Challenges in radical/nonradical-based advanced oxidation processes for carbon recycling

Advanced oxidation processes (AOPs) have been extensively investigated on catalytic degradation of organics to carbon dioxide as well as synthesis of macromolecules via free radical-initiated polymerization (RP-AOPs). More recently, nonradical oxidation pathways have been reported in AOPs, which can also trigger polymerization (NRP-AOPs) with high selectivity due to the mild oxidative potential and favorable reaction pathways. In this perspective, we present the advances in RP/NRP-AOPs for innovative polymer manufacture for carbon recycling and classify the polymerization of various monomer compounds, including phenolic, aniline, thiophene, and vinyl monomers. The origins and pathways of polymerization reactions are discussed. We particularly highlight the recent discoveries of NRP-AOPs and the reaction parameters of RP/NRP-AOPs to synthesize various value-added polymers in water, featured by an easy-to-handle system with mild reaction conditions and low chemical input, providing instructional strategies to prepare the value-added polymers from organic wastes to minimize carbon footprint and achieve a circular economy.