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)34-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 (SU/V = 600) but also a uranium uptake of 16.91 mg/g from natural seawater in 7 days.
Gao et al. (2026) studied this question.