Atomic H* mediated fast decontamination of antibiotics by bubble-propelled magnetic iron-manganese oxides core-shell micromotors

Abstract

Wastewater remediation using micro/nanomotors is a hot topic, and MnO2 based materials have become fascinating alternatives to rare noble metal-based micro/nanomotors. Herein, we demonstrate facile and large- scale synthesis of Fe-MnO2 core-shell micromotors for antibiotic pollutant removal. Heat-treatment results in a phase transformation of MnO2 with formation of iron oxides and partially exfoliates the MnO2 nanoplate shell structure to promote mobility. The iron-manganese oxide micromotors exhibit an efficient removal of tetracy- cline antibiotics via a combination of catalytic degradation and adsorptive bubble separation. For the first time, atomic H* was found to participate in the micromotor-assisted degradation process, resulting in optimal Fenton reaction in neutral conditions with a good decontamination performance. Owing to the merits of abundance, magnetic recovery, facile fabrication, good motion, and environmental friendliness, as well as decontamination performance in a wide pH range, these core-shell micromotors demonstrate a promising candidate in practical wastewater treatment.