Effect of Functional Groups on the I 2

In this work, the effect of functional groups on I2 sorption kinetics is investigated using two different types of isostructural metal-organic frameworks, UiO-66-X series (X = H, Br, NO2, NH2, (OH)2, and (COOH)2) and M2(m-DOBDC) series, (M = Co2+, Mg2+, and Ni2+; m-DOBDC4− = 4,6-dioxo-1,3-benzenedicarboxylate). Among the UiO-66-X series, UiO-66-(COOH)2 exhibits the fastest sorption kinetics and the highest sorption capacity due to dipole-induced dipole interactions between carboxylic acid groups and I2 molecules. In addition, faster I2 chemisorption is observed in M2(m-DOBDC) because of electrophilic aromatic substitution of m-DOBDC4− with I2. The I2 sorption mechanisms are further supported by fitting the I2 adsorption kinetics data to pseudo-first-order and pseudo-second-order kinetic models. © 2021 Korean Chemical Society, Seoul & Wiley-VCH GmbH1