Electrochemically Driven Uranium Capture via Polymer-Based Capacitive Deionization for Radioactive Wastewater Remediation

The removal of uranium(VI) from wastewater is crucial for environmental protection and the development of sustainable nuclear energy. Capacitive deionization (CDI) represents a promising electrochemical strategy, yet its deployment in uranium remediation has been hindered by the absence of efficient electrode materials. Herein, we report a redox-active polymer (PyHATP) electrode that introduces a novel coordination-driven electrochemical extraction concept for highly efficient uranium capture. The π-delocalized framework and abundant redox-active moieties synergistically enhance charge transport and promote reversible UO22+ coordination. In situ characterizations, density functional theory, and molecular dynamics simulations reveal a strong chelation between UO22+ and C═N bonds in the PyHATP lattice, underpinning its selectivity and performance. A proof-of-concept CDI device achieves a record UO22+ adsorption capacity of 676.4 mg g–1, outstanding regeneration stability, and environmental compatibility. In real uranium-contaminated seawater, the system maintains >90% removal efficiency. These findings establish polymer-based CDI as an efficient, selective, and sustainable platform for radioactive wastewater remediation.