Highly efficient activation of peroxymonosulfate by Co3O4/Bi2MoO6 p-n heterostructure composites for the degradation of norfloxacin under visible light irradiation

Abstract Photocatalytic technology assisted via peroxymonosulfate (PMS) has good potential in water treatment. In the study, the Co3O4/Bi2MoO6 p-n heterostructure photocatalyst was prepared via an in-situ calcination process and was applied to activate PMS for degrading norfloxacin (NFA) under visible light irradiation. The obtained 5 wt% Co3O4/Bi2MoO6/PMS can effectively remove 87.68% of NFA within 30 min under visible light irradiation. The excellent degradation performance of Co3O4/Bi2MoO6/PMS system can be attributed to the synergistic effect between p-n heterojunction and PMS activation. The conduction band and valence band deviation between Co3O4 and Bi2MoO6 were calculated according to XPS techniques, and the results of anion interference experiments and circulation experiments revealed that the Co3O4/Bi2MoO6/PMS system has good stability. Besides, the possible degradation pathways of NFA were proposed and DFT calculations were performed to further confirm the internal structure between Co3O4 and Bi2MoO6. This work provides a new idea and a new catalyst for the degradation of organic pollution in water.