A Water Stable Cationic MOF with Hydrophobic Pore Surface as Efficient Scavenger of Oxo-anion Pollutants from Water

Abstract

Water contamination due to heavy metal-based toxic oxo-anions (such as CrO42-, 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 as well as a record high uptake capacity for CrO42- (476.3 mg g-1) and ReO4- (691 mg g-1), while the later 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.