Carbazole-Bearing Conjugated\nMicroporous Polymer Electrodes\nfor Uranium Extraction from Seawater with Good Anti-biofouling Feature

Emerging electrochemical uranium extraction from seawater\noffers\na promising route for a sustainable fuel supply for nuclear reactor\noperation. In this work, we intentionally synthesized a conjugated\nmicroporous polymer (CMP) with π-conjugated skeletons and permanent\nporosity, which was induced by in situ electropolymerization on flexible\ncarbon cloths, followed by postdecorating amidoxime groups to create\nfunctional materials (CMP-AO). Driven by an extra asymmetrical alternating\ncurrent electrochemical extraction, the self-supporting and binder-free\nelectrode is exceptionally capable of selectively and rapidly capturing\nU(VI) from simulated solution, affording an extraction capacity of\n∼1806.4 mg/g without saturation. Experimental observation in\ncombination with ex/in situ spectroscopy revealed that CMP-AO enabled\nsurface selective binding sites (amidoxime groups) to U(VI), followed\nby electrocatalytic reduction (carbazole groups) to yield yellow precipitates\n(Na<sub>2</sub>O(UO<sub>3</sub>·H<sub>2</sub>O)<sub><i>x</i></sub>) via reversible electron transfer in the presence of sodium\nelectrolyte. Furthermore, the integrating adsorption-electrocatalysis\nsystem achieved an extraction capacity of 18.8 mg/g in real seawater\nfor 21 days and good antibiofouling abilities, validating its feasibility\nfor practical application.