Electro-driven uranium extraction from uranium-bearing waters

Abstract

Abstract

Electrochemical uranium extraction (EUE) is an emerging technology to address the urgent need for treating uranium-bearing waters, including seawater, uranium mine wastewater, and nuclear industry wastewater. Within an electric field, EUE drives the directional migration of uranyl ions, enabling soluble uranyl species to be enriched or reduced to insoluble uranium products, thereby achieving uranium recovery from uranium-bearing waters. The coordination environment of uranyl and its electrochemical interfacial extraction behavior are key to determining EUE efficiency. This review provides a timely overview of advances in EUE. Initially, from the perspectives of uranium mass transfer, coordination enrichment, electron transfer, and deposition recovery, we analyze the advantages and limitations of four representative EUE technologies, including capacitive deionization, electrodeposition, electrochemical reduction, and photoelectrochemical reduction, and elucidate the underlying uranyl coordination chemistry and extraction mechanisms. Given the critical role of electrode materials in regulating the uranyl coordination environment, this review focuses on their rational design, covering extraction mechanisms and structure-activity relationships, combined with electrochemical regulation strategies and device configuration optimization, aiming to provide guidance for the development of high-performance electrodes and devices for uranium extraction. Finally, key challenges and future perspectives for EUE are outlined to inspire innovative strategies and cost-effective solutions, thereby facilitating the wider adoption of EUE technology and supporting the sustainable utilization of uranium resources.