Innovative Conversion Strategy for Wastewater with One‐Pot Uranium Extraction and Valuable Chemical Production by a Smart COF Photocatalyst

Environmental protection and resource reclamation make the extraction of uranium from uranium‐containing wastewater be a key role in the nuclear chemistry and industry. Although previous studies have revealed several effective methods and materials for such use, however, few studies are concerned about the wastewater discharge issues. In fact, the direct discharge of treated wastewater into the environment is still not a green way. Here, an innovative conversion approach is shown, which can simultaneously achieve the uranium extraction and conversion of wastewater to valuable chemical. This concept is implemented by an azobenzene‐pendent covalent organic framework, showing smart trans‐to‐cis photoresponsive properties in both space and electronic structure and consequently, largely enhanced extraction and conversion efficiency under UV irradiation, relative to visible light irradiation. In real wastewater, the material is found to give selective and 100% uranium extraction and H2O2 generation (1872.3 µmol g−1 h−1). The mechanism is due to a unique photocatalysis coupling between the uranium reduction reaction (URR), aiming at uranium recovery or removal, and the water oxidation reaction (WOR), targeting the conversion of wastewater into a valuable chemical of H2O2. A new concept of isomerization‐promoted photocatalysis in an azobenzene‐pendent COF is demonstrated here. And a positive coupling effect between two photocatalysis reactions is also for the first time observed, thus providing a promising pathway for uranium‐containing wastewater treatment with both uranium removal and H2O2 production.