Synthesis of magnetic biomass carbon-based Bi2O3 photocatalyst and mechanism insight by a facile microwave and deposition method

A novel magnetic double-conductive photocatalyst of Fe3O4@Bi2O3/C was successfully prepared by microwave and deposition technology, and it showed satisfactory photocatalytic activity in the degradation of tetracycline compared with that of pure Bi2O3 under visible light. The improved degradation efficiency of the as-prepared Fe3O4@Bi2O3/C is attributed to the better conductivity of biomass carbon and Fe3O4 quantum dot, which significantly inhibited the recombination of electron–hole pairs and improved the optical absorption. In addition, the mechanism exploration of the radical trapping experiments and ESR measurement indicated that h+, ˙O2− and ˙OH participated in the tetracycline removal procedure. The possible photocatalytic reaction mechanisms including transfer behavior of charge carriers and the intermediate products of tetracycline degradation were also revealed in depth. This work provides a promising approach to construct a biomass carbon-based photocatalyst for the wastewater treatment.