A Supramolecular Organic Framework‐Mediated Electrochemical Strategy Achieves Highly Selective and Continuous Uranium Extraction

Abstract

AbstractThe integration of selectivity and electron transfer ability remains a primary challenge in developing electrode materials for uranium electroextraction. Herein, a phenanthroline‐based supramolecular organic framework (MPSOF) is elaborately constructed as a pioneering cathode material through the hydrogen bond‐driven self‐assembly of melamine and 1,10‐phenanthroline 2,9‐dicarboxylic acid (PDA) for selective and continuous electrochemical uranium extraction (EUE). PDA moieties selectively capture UO22+, while the hydrogen bond‐supporting frameworks provide an efficient electron transfer channel for the redox of UO22+. These structural features enable the rapid formation and spontaneous shedding of uranium precipitate from MPSOF, allowing for the regeneration of the selective adsorption sites. As a result, MPSOF‐mediated EUE exhibits a high extraction capacity of 7311 mg U g−1 at a low voltage of −3.5 V but does not reach equilibrium. Cyclic EUE is employed to uranium extraction from simulated high‐salt radioactive effluents and attains high selectivity for uranium. The electroextraction mechanism is confirmed, wherein uranium species transform into (UO2)O2·4H2O. This work not only provides an efficient electrode material for uranium electroextraction, but also presents a novel electrochemical strategy for separation and adsorption of other radionuclides and contaminant ions.