Layered charge separation in surface boron doped copper with phosphate groups boosts the electrochemical uranium extraction from seawater

Abstract

Electrochemical uranium extraction from seawater is an attractive project for sustainable nuclear industry, whereas the active sites of electrode materials require further promotion on uranyl binding to increase the efficiency and kinetics of uranium extraction. Herein, we construct a strategy of layered charge separation in surface boron-doped copper with surface phosphate ions (B:Cu-PO4) for charge-enhanced uranyl binding and extraction in seawater. The B atoms were demonstrated to decrease the negative charge in surface Cu atoms and increase the negative charge in outer O atoms of PO43- groups, thus enhancing the uranyl binding. In a real seawater experiment, the B:Cu-PO4 extracted 24.9 μg of uranium from 10 L of seawater. Such performance corresponded to a considerable extraction capacity of 2.1 mg/g per day, which outperformed most of the state-of-the-art materials. The successful construction of charge separation in B:Cu-PO4 broadened the material design for uranium extraction from real seawater.