Bipolar electrochemical uranium extraction from seawater with ultra-low cell voltage

Efficient uranium extraction from seawater has the potential to secure an abundant and reliable supply of nuclear fuel, providing affordable energy with minimized carbon emissions. Among the many extraction methods, the electrochemical route has emerged as a promising choice owing to its fast kinetics and materials regeneration. The major challenges facing this technology, however, lie in its high energy consumption, low extraction efficiency and poor selectivity. Here we show a bipolar electrochemical uranium extraction (EUE) system that combines cathodic direct electroreduction of uranium species and electrochemistry-assisted indirect uranium reduction at the anode. The EUE device operates at an ultra-low voltage of merely 0.6 V, exhibiting an efficiency of ~100% for sources with a wide range of uranium concentrations (1–100 ppm). This bipolar EUE system in natural seawater displays excellent uranium selectivity (above 85.3%), long-term stability (45 cycles), low energy consumption (1,944 kWh kg−1 U) and cost advantage (US$83.2 kg−1 U). This work opens an avenue to the electrochemical system design for sustainable recycling of different waste resources.