Solvothermal synthesis of Zr-based MOFs with mixed linker as adsorbent for methyl orange in water

Abstract UiO-66 is one type of Zr-based MOF consisting of ZrO 4 (OH) 4 polyhedral. Synthesis of materials UiO-66 mixed linker with additional acetic acid modulator was successfully carried out by the solvothermal method at 120°C. UiO-66 modified with mixed linker can improve stability in water that has systematically and functionally modulated pores. When the concentration of each linker increases, the linkers merge in one place and produce cluster defects. UiO-66 mixed linker was synthesized with a ratio of adding H 2 BDC and NH 2 BDC of 3:1 to moles of ligand. The X-ray diffraction (XRD) pattern and Fourier transform infrared (FTIR) spectra of the synthesized material have the same pattern with the peak characteristics of UiO-66 and UiO-66-NH 2 . The synthesized material has a spherical morphology with a rough surface. The performance of the materials as an adsorbent for methyl orange (MO) dyes in water reached a maximum adsorption capacity of 202.82 mg/g for materials UiO-66 mixed linker (75% H 2 BDC and 25% NH 2 BDC). The adsorption results for all the synthesized materials followed the apparent pseudo-second-order kinetics and Langmuir isotherm. The adsorption mechanism between the adsorbent and methyl orange dyes consists of π-π interactions, hydrogen bonds, and electrostatic interactions.