Preparation of Fe₃O₄@UiO-66 and Study on Its Adsorption of Oxytetracycline

As one of the most stable metal-organic frame materials (metal-organic frameworks, MOFs), UiO-66 has attracted extensive attention in the adsorption field. However, the use of UiO-66 is still limited by the weak electron-hole charge separation ability or the low accessibility of micropores. In this study, Fe₃O₄@UiO-66 was prepared by using acetic acid to construct the mesoporous defects of UiO-66 and doping Fe₃O₄. The doping of Fe₃O₄ results in the formation of denatured mesoporous defects in UiO-66, leading to good performance on adsorption of tetracycline antibiotics. Fe₃O₄@UiO-66 was used to adsorb and remove common oxytetracycline (OTC) from water. The adsorption properties and mechanism of Fe₃O₄@UiO-66 on OTC were studied by analyzing the crystal structure and physicochemical properties of Fe₃O₄@UiO-66. The results show that the adsorption capacity of Fe₃O₄@UiO-66 was 201.72 mg·g^-1, and the removal rate of OTC was 80.69%. The adsorption process conforms to the pseudo-second-order kinetics, Elovich and Langmuir isothermal adsorption model. Adsorption reaction is endothermic reaction and with entropy increase process. The increase of temperature is beneficial to the adsorption. The adsorption reaction is less affected by pH.