Self-Assembly Approach for Uranium Extraction from Seawater

Efficient uranium extraction from seawater remains a highly challenging task due to the lack of an available approach to access a precise uranium-identified site in the adsorbent. To this end, we demonstrate herein a novel in situ self-assembly approach by directly using two organic molecules, 2,6-pyridinedicarboxaldehyde and terephthalohydrazide, to execute in situ in-plane self-assembly with [UO₂(CO₃)₃]^4-composite anions through both covalent Schiff base condensation and coordination with UO₂²⁺ ions. Through such a self-assembly approach, we can create a precise UO₂²⁺-identified site conveniently, thus allowing for not only a record uranium selectivity over vanadium (<i>S</i>_U/V = 600) but also a uranium uptake of 16.91 mg/g from natural seawater in 7 days.