Acceptor Modulation in Benzotrithiophene‐Based Covalent Organic Frameworks for Highly Efficient Photocatalytic Uranium Recovery

Photocatalytic uranium conversion in an air atmosphere is closely related to the generation of reactive oxygen species (ROS), including H 2 O 2 and .O 2 − . Highly effective visible light‐driven uranium extraction without sacrificial agents is highly demanded but limited by inefficient photocarrier separation/transportation and ROS production. Herein, a facile acceptor regulation strategy was developed to fabricate two benzotrithiophene‐based covalent organic frameworks (BTT‐DAB and BTT‐BD) with modulated π skeletons. The introduction of aromatic amines ligands DAB with a lower torsion angel not only improves the structural planarity but also decreases the distance between BTT donors. BTT‐DAB shows optimized visible light harvesting capability and accelerated charge dissociation/transfer owing to the planar and continuous π ‐electron delocalization channels. BTT‐DAB exhibits high uranium extraction efficiency, excellent selectivity and reusability under visible light. The in situ generated H 2 O 2 is promoted in BTT‐DAB through a two step 1 e −1 oxygen reduction reaction, which facilitates the precipitation of uranium as metastudtite. This work highlights a facile but general structural regulation strategy to enhance the photocatalytic uranium extraction performance.