Effect of Functional Groups on the <scp>I₂</scp> Sorption Kinetics of Isostructural <scp>Metal–Organic</scp> Frameworks

Abstract

In this work, the effect of functional groups on I 2 sorption kinetics is investigated using two different types of isostructural metal‐organic frameworks, UiO‐66‐X series (X = H, Br, NO 2 , NH 2 , (OH) 2 , and (COOH) 2 ) and M 2 ( m ‐DOBDC) series, (M = Co2+, Mg2+, and Ni2+; m ‐DOBDC 4− = 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 I 2 molecules. In addition, faster I 2 chemisorption is observed in M 2 ( m ‐DOBDC) because of electrophilic aromatic substitution of m ‐DOBDC 4− with I 2 . The I 2 sorption mechanisms are further supported by fitting the I 2 adsorption kinetics data to pseudo‐first‐order and pseudo‐second‐order kinetic models.