Preparation of highly-hydrophobic novel N-coordinated UiO-66(Zr) with dopamine via fast mechano-chemical method for (CHO-/Cl-)-VOCs competitive adsorption in humid environment

A novel mechano-chemical strategy using dopamine to modify UiO-66(Zr) by N-coordination was proposed to enhance its competitive adsorption for acetaldehyde, chlorobenzene/H 2 O, both thermodynamically and kinetically. The newly synthesized material was characterized by SEM, EDX, XPS, PXRD, FT-IR, TGA/DTG and BET techniques. Results showed that N was successfully grafted into UiO-66(Zr) frameworks through coordination interaction with Zr-O clusters resulting in M-UiO-66(Zr-N 3.0 ). The obtained M-UiO-66(Zr-N 3.0 ) exhibited a significant increase in adsorption of chlorobenzene (4.94   mmol/g) and acetaldehyde (9.42   mmol/g) compared to parent UiO-66(Zr) and UiO-66(Zr)-NH 2 . The H 2 O adsorption uptake of M-UiO-66(Zr-N 3.0 ) decreased by 20% that of UiO-66(Zr) and 47% of UiO-66(Zr)-NH 2 indicating higher hydrophobicity of the modified material. Kinetic performance indicated that diffusivity of chlorobenzene on M-UiO-66(Zr-N 3.0 ) was about 7.8 and 40   times higher than that of the parent UiO-66(Zr) and UiO-66(Zr)-NH 2 respectively and 15.4   times higher than that of H 2 O on itself. Based on the results, the current N-modification strategy can be deemed as an efficient way to improve MOFs competitive adsorption towards VOCs under humid conditions and it might play active role in industries involving adsorbent applications.