Optimizing zirconium metal–organic frameworks through steric tuning for efficient removal of Cr2O72−

Abstract

A ligand with a flexible conformation can be obtained by modifying functional groups. We modified H₄DCBA with –CH₃/–CF₃ groups to construct three Zr-MOFs; the torsion of the central benzene ring changes the topologies. The three Zr-MOFs showed high adsorption rates for Cr₂O₇²⁻, and the CF₃-functional groups enhanced the adsorption capacity of UPC-49 for Cr₂O₇²⁻.