One-Pot Synthesis of Magnetically Recyclable Fe3o4@Uio-66 Composite with Enhanced Oxytetracycline Adsorption Capacity

Graphical OTC molecules diffuse to the surface of FU3 to cause film diffusion, and continue to diffuse and fill into large-, medium- and micro-pores of FU3. FU3 can be π─π conjugated and cation─π bonded with the benzene rings and amino groups of OTC. The charged surface of FU3 leads to a strong electrostatic effect in the adsorption process. The doping of Fe 3 O 4 produces structural defects to promote the OTC adsorption. As one of the most stable metal-organic frame materials (MOFs), UiO-66 has attracted extensive attention in the adsorption field. However, the application of UiO-66 is still constrained by the weak electron-hole charge separation capability and the low accessibility of micropores. In this study, the mesoporous defects of UiO-66 were constructed with acetic acid and doped with Fe 3 O 4 to prepare magnetically recyclable Fe 3 O 4 @UiO-66. The doping of Fe 3 O 4 resulted in the formation of denatured mesoporous defects in UiO-66, which was conducive to adsorption oxytetracycline (OTC) in water. The crystal structure and physicochemical characteristics of Fe 3 O 4 @UiO-66 were examined. By using the static adsorption technique, the adsorption characteristics and mechanism of OTC on Fe 3 O 4 @UiO-66 were investigated. The results reveal that Fe 3 O 4 @UiO-66 has an adsorption capacity of 210 mg g −1 and an OTC removal ratio of 84.0%. The pseudo-second-order kinetics, Elovich, and Langmuir isothermal adsorption models were all applicable to the adsorption process. The adsorption process increased entropy and was an endothermic reaction. Solution pH has a little effect on the adsorption performance. This study provides the possibility of one-step synthesis of MOFs that can efficiently adsorb tetracycline antibiotics in water with low cost and excellent recyclability and reusablity.