Tunable perylene-based donor-acceptor conjugated microporous polymer to significantly enhance photocatalytic uranium extraction from seawater

Herein, we present a molecular engineering strategy to boost the photocatalysis performance of donor-acceptor conjugated microporous polymers (C?s) for U(VI) reduction under visible-light. With perylene as donor and tailoring acceptors from 9H-fluoren-9-one to dibenzo[b,d]thiophene 5,5-dioxide, two new C?s, named ECUTCO and ECUT-SO, were obtained. Notably, both experiments and DFT calculations certificated the high dependence of photocatalytic activity upon the acceptors. Consequently, ECUT-SO with the strongest acceptor enables ultrahigh photocatalytic performance for uranium (VI) reduction, giving 97.8% reduction efficiency within 60 min, surpassing most reported photocatalysis materials for such use. The excellent photocatalysis ability was mainly due to that D-A configuration ECUT-SO affords optimized visible-light response, excellent photo-exciton separation and stronger coordination sites for UO22+. Importantly, by means of this photocatalytic technology, ultrahigh uranium extraction capacity of 1.78 g/g with a nearly 100% extraction efficiency was achieved in U(VI)-spiked real seawater, suggesting its superior application in extraction of uranium from seawater.