Synthesis and adsorption properties investigation of Fe3O4@ZnAl-LDH@MIL-53(Al) for azole fungicides removal from environmental water

Abstract

• A novel Fe 3 O 4 @Zn 2 Al-LDH@MIL-53(Al) was synthesized by a facile two-step process. • The material was used for the removal of azole fungicides from environmental water. • The equilibrium was reaching within 5 min with high adsorption capacity. • The mechanisms were including hydrogen-bonding interaction and π–π interaction. In this work, a novel Fe 3 O 4 @ZnAl-LDH@MIL-53(Al) composite was synthesized by a facile three-step process and utilized as an adsorbent for the removal of azole fungicides from environmental water. The characterization results revealed that double hydroxide (ZnAl-LDH) and metal organic framework (MIL-53) have been successfully tethered to the shell of Fe 3 O 4 . The main factors affecting the removal efficiencies were investigated, and results revealed that Fe 3 O 4 @ZnAl-LDH@MIL-53(Al) composite possessed high removal efficiencies for azole fungicides. Furthermore, the adsorption mechanism was investigated and including hydrogen-bonding interaction, chemisorption and π–π interaction. The adsorption kinetic was more consistent with the pseudo-second-order kinetic model, and the whole adsorption process could reach the equilibrium within 5 min. Langmuir adsorption isotherm model could describe the adsorption process most accurately, and the maximum adsorption values of azole fungicides were in the range of 43.54–71.79 mg g −1 . Meanwhile, the adsorption thermodynamics indicated that the adsorption process was exothermic and spontaneous. Hence, Fe 3 O 4 @ZnAl-LDH@MIL-53(Al) composite had a great application potential in the removal of azole fungicides from the environment.