Carbazole-Bearing Conjugated Microporous Polymer Electrodes for Uranium Extraction from Seawater with Good Anti-biofouling Feature

Emerging electrochemical uranium extraction from seawater offers a promising route for a sustainable fuel supply for nuclear reactor operation. In this work, we intentionally synthesized a conjugated microporous polymer (CMP) with π-conjugated skeletons and permanent porosity, which was induced by in situ electropolymerization on flexible carbon cloths, followed by postdecorating amidoxime groups to create functional materials (CMP-AO). Driven by an extra asymmetrical alternating current electrochemical extraction, the self-supporting and binder-free electrode is exceptionally capable of selectively and rapidly capturing U(VI) from simulated solution, affording an extraction capacity of ∼1806.4 mg/g without saturation. Experimental observation in combination with ex/in situ spectroscopy revealed that CMP-AO enabled surface selective binding sites (amidoxime groups) to U(VI), followed by electrocatalytic reduction (carbazole groups) to yield yellow precipitates (Na2O(UO3·H2O)x) via reversible electron transfer in the presence of sodium electrolyte. Furthermore, the integrating adsorption-electrocatalysis system achieved an extraction capacity of 18.8 mg/g in real seawater for 21 days and good antibiofouling abilities, validating its feasibility for practical application.