A Water-Stable Cationic Metal–Organic Framework with Hydrophobic Pore Surfaces as an Efficient Scavenger of Oxo-Anion Pollutants from Water

Water
contamination due to heavy metal-based toxic oxo-anions (such
as CrO42– and TcO4–) is a critical environmental concern that demands immediate mitigation.
Herein, we present an effort to counter this issue by a novel chemically
stable cationic metal–organic framework (iMOF-2C) with strategic
utilization of a ligand with hydrophobic core, known to facilitate
such oxo-anion capture process. Moreover, the compound exhibited very
fast sieving kinetics for such oxo-anions and a very high uptake capacity
for CrO42– (476.3 mg g–1) and ReO4– (691 mg g–1), while the latter being employed as a surrogate analogue for radioactive
TcO4– anions. Notably, the compound showed
excellent selectivity even in the presence of other competing anions
such as NO3–, Cl–,
SO42–, ClO4–. etc.. Furthermore, the compound possesses excellent reusability
(up to 10 cycles) and is also employed to a stationary phase ion column
to decontaminate the aforementioned oxo-anions from water.