Optimizing Zirconium Metal—Organic Frameworks through Steric Tuning for Efficient Removal of Cr2O72−

The ligand with 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 the UPC-49 for Cr2O72-.