Facile synthesis of magnetic framework composite MgFeO@UiO-66(Zr) and its applications in the adsorption-photocatalytic degradation of tetracycline.

Recently, metal-organic framework (MOF)-based hybrid composites have attracted significant attention in photocatalytic applications. In this work, MgFeO@UiO-66(Zr) (MFeO@UiO) composites with varying compositions were successfully synthesized via facile in situ assemblies. Depositing the UiO-66(Zr) framework onto ferrite nanoparticles yielded a composite structure having a lower bandgap energy (2.28-2.60 eV) than that of the parent UiO-66(Zr) (~3.8 eV). Moreover, the MFeO@UiO composite exhibited magnetic separation property and improved porosity. The removal experiment for tetracycline (TC) in aqueous media revealed that the MFeO@UiO composite exhibited a high total TC removal efficiency of ca. ~94% within 45-min preadsorption and 120-min visible-light illumination, which is higher than that of pristine ferrite and UiO-66(Zr). The enhanced photodegradation efficiency of MFeO@UiO is attributed to efficient interfacial charge transfer at the heterojunction and the synergistic effect between the semiconductors. Radical scavenging experiments revealed that photogenerated holes (h) and hydroxyl radicals (·OH) were the major reactive species involved in TC photodegradation. Moreover, the prepared MFeO@UiO nanocomposite showed good recyclability and renewability, making it a potential material for wastewater treatments.