Umbellate Distortions of the Uranyl Coordination Environment Result in a Stable and Porous Polycatenated Framework That Can Effectively Remove Cesium from Aqueous Solutions

Searching
for new chemically durable and radiation-resistant absorbent
materials for actinides and their fission products generated in the
nuclear fuel cycle remain highly desirable, for both waste management
and contamination remediation. Here we present a rare case of 3D uranyl
organic framework material built through polycatenating of three sets
of graphene-like layers, which exhibits significant umbellate distortions
in the uranyl equatorial planes studied thoroughly by linear transit
calculations. This unique structural arrangement leads to high β
and γ radiation-resistance and chemical stability in aqueous
solutions within a wide pH range from 3 to 12. Being equipped with
the highest surface area among all actinide compounds known to date
and completely exchangeable [(CH3)2NH2]+ cations in the structure, this material is able to
selectively remove cesium from aqueous solutions while retaining the
polycatenated framework structure.