The sustainable upcycling of plastic waste under ambient conditions remains a major challenge due to the lack of efficient, robust, and environmentally benign photocatalysts. Here we report a green and metal-free strategy for the synthesis of conjugated microporous polymers (CMPs) that directly addresses this challenge. The polymers are prepared using natural sunlight to drive polymerization through in situ-formed electron donor-acceptor (EDA) complexes, eliminating the need for harsh conditions or precious metals. The resulting CMPs, TMPB-AQ and TTPM-AQ, function as efficient heterogeneous photocatalysts for the ambient-temperature upcycling of ten types of real-world polystyrene-based plastics into value-added benzoic acid. The process is readily scalable to gram quantities in both batch and continuous-flow reactors and maintains high catalytic performance over eleven reuse cycles, highlighting its practical durability. Mechanistic insights from combined experimental and computational studies reveal that the high activity originates from the intrinsic porosity and extended conjugation of the CMPs, which promote spontaneous adsorption of polystyrene chains, efficient mass transport, and effective charge separation at the polymer-plastic interface. Overall, this work demonstrates a sustainable pathway that integrates green materials synthesis with the productive valorization of plastic waste, advancing circular-economy approaches to polymer recycling.
Dong et al. (Mon,) studied this question.