UiO-66
metal–organic frameworks (MOFs) are unstable in some
harsh aqueous environments, which limit their practical applications.
We demonstrate a postsynthetic modification methodology to transform
hydrophilic Zr(Hf)-UiO-66 into superhydrophobic Zr(Hf)-UiO-66-SH-y (SH = thiol, y = fluoroalkyl) by introducing
long fluoroalkyl chains into organic linkers through a thiol–ene
click reaction. Water contact angles of the four modified UiO-66 MOFs
are all larger than 150°. The grafted low-surface-energy fluorine-containing
groups become an effective protective shield for the MOFs, making
them exhibit remarkable stability in extreme conditions such as alkaline
(pH = 12), saturated HCl, and high concentration of NaCl solution
(20 wt %). The Zr-UiO-66 MOFs grafted with 1H,1H,2H-perfluoro-1-hexene have high CO2 adsorption contents of 1.54 and 2.88 mmol·g–1 at 298 and 273 K, respectively. Moreover, the superhydrophobic MOFs
also showed potential application in oil/water separation.