The Synthesis, Application and Mechanism of a Novel Zr-Based Magnetic Mofs Adsorption Material

Abstract

In the current study, a novel material Fe3O4@PDA@UiO-67 was synthesized by combining magnetic polydopamine (PDA) and zirconium-based metal-organic framework UiO-67 as well as applied as an adsorbent to remove azole fungicides in environmental water. The morphology and structure of this synthesized material were confirmed through a series of characterization. Modifying of UiO-67 on magnetic PDA could dramatically expand the surface area, enlarge the porosity and pore volume, and therefore improving the adsorption of pesticides. In addition, the effects of adsorbent dosage, solution pH, ionic strength and material composition on adsorption capability were evaluated and optimized. Under optimal conditions, the removal efficiencies were more than 90 %. Furthermore, the adsorption mechanism was revealed by Fourier transform infrared (FT-IR), X-ray photoelectron spectroscopy (XPS) analysis and density functional theory calculations. Hydrogen bonds were considered as the major intermolecular interaction between the MOF backbones and the target pollutants. The binding energy 〖∆E〗b  of epoxiconazole and flusilazole are -18.63 kJ/mol and -28.54 kJ/mol, respectively, which are in consist with the maximum adsorption value for flusilazole (43.54 mg g-1) and flusilazole (54.60 mg g-1). In general, the synthesized Fe3O4@PDA@UiO-67 shows great potential in removing the environmental pollutants.

Keywords: Azole pesticides, Magnetic polydopamine, UiO-67, DFT calculations, Removal effectively