Magnetically sensitive TiO2 hollow sphere/Fe3O4 core-shell hybrid catalyst for high-performance sunlight-assisted photocatalytic degradation of aqueous antibiotic pollutants

Abstract

Owing to the ease of catalyst separation and recycling, magnetically sensitive catalysts are essential for developing a cost-effective method for the photocatalytic degradation of aqueous organic pollutants. This study demonstrates the efficacy of a magnetically sensitive TiO2 hollow sphere/Fe3O4 (THS/FO) core-shell hybrid catalyst for the sunlight-assisted degradation of aqueous antibiotic pollutants, namely amoxicillin (AMC) and levofloxacin (LVF). To fabricate this core-shell hybrid catalyst, THS was first synthesized via a wrap–bake–peel approach using SiO2 templates and FO nanoparticles were then carefully deposited on the THS surface via an in situ growth method. The THS/FO core-shell hybrid catalyst exhibited significantly higher activity for degrading AMC and LVF than THS under simulated sunlight. Moreover, the activity results indicate that the proposed hybrid catalyst outperforms numerous reported photocatalysts owing to its strong optical response properties and the synergistic effect of THS and FO due to the core-shell configuration of the hybrid catalyst, which facilitates charge separation. Additionally, due to the strong magnetic properties of the hybrid catalyst, the catalyst can be magnetically recovered and reused in the AMC and LVF degradation processes without exhibiting a significant loss in its activity even after five consecutive test cycles. Thus, the hybrid catalyst designed herein promotes the use of practical photocatalytic techniques for treating aqueous antibiotic pollutants.