Molybdate Anion‐Doped Porous Electrodes with Oxygen‐Bridging Mode for Efficient Electroreduction of Uranium(Vl)

Abstract The electroreduction of uranyl ions from seawater is a promising and sustainable method to smelt uranium (U) for the nuclear power industry. However, electrostatic repulsion prevents conventional catalytic centers in terms of nanoparticles and cations from making full contact with uranyl ions, leading to poor uranium extraction performance of the electrode materials. Herein, molybdate anions serving as electronegative catalytic centers are integrated into a porous aromatic framework to obtain the porous electrode (Mo@PAF‐6). The metalate anions in Mo@PAF‐6 bind U(VI) cations in the form of Mo─O─U bonds; since the relative distance is limited in the range of 3−4 Å, U(VI) is electrically reduced to U(V) and precipitated as charge‐neutral species. Mo@PAF‐6 outperforms conventional catalysts with electropositive metal centers by 100% for uranium extraction in an 8 ppm uranium‐spiked solution. Moreover, the uranium extraction capacity of Mo@PAF‐6 in real seawater reaches 24.21 mg g −1 during 56 days‐contact, far exceeding that of the classical poly(amidoxime)‐based electrode by a factor of ≈12 000.