LAUSR

The discovery of novel high-nuclearity oxo-clusters considerably promotes the development of cluster science. We report a high-nuclearity oxo-cluster based compound with acid/alkali-resistance and radiation stabilities, namely (H3O)7[Cd7Sb24O24(L-tta)9(L-Htta)3(H2O)6]•29H2O (FJSM-CA; L-H4tta = L-tartaric acid), which features a two-dimensionally anionic layer based on the largest Sb-oxo-clusters with 28-metal-ion-core [Cd4Sb24O24]. It is challenging to efficiently capture Sr2+, Ba2+ (analogue of 226Ra) and [UO2]2+ ions from aqueous solutions due to their high water-solubility and environmental mobility, while it is unprecedented that a novel Sb-oxo-cluster based framework material FJSM-CA can efficiently remove these hazardous ions accompanied with intriguing structural transformations. Especially, it shows fast ion-exchange abilities for Sr2+, Ba2+ and [UO2]2+ (reaches equilibrium within 2, 10, 20 minutes, respectively) and high exchange capacity (121.91 mg/g), removal rate R (96%) and distribution coefficient KdU (2.46 × 104 mL/g) for uranium. Moreover, the underlying mechanism is clearly revealed which is attributed to strong electrostatic interactions between exchanged cations and highly negative charged frameworks, and the strong affinity of (COO)- groups for these cations. Proton conduction of the pristine and Sr2+, Ba2+, [UO2]2+-loaded products were investigated. This work highlights designing new oxo-cluster based materials for radionuclide remediation and proton conduction performance.