Light-mediated enhancement effect derived from carbon nitrogen polymer to regulate peroxymonosulfate activation over Co3O4 for effective degradation of fluorinated pharmaceuticals

The pollution problem caused by fluorinated pharmaceutical is a big challenge facing humanity, and it is of great significance to develop an effective remediation method. Herein, Co 3 O 4 /g-C 3 N 4 composites with photocatalytic activity are synthesized and employed to activate Peroxymonosulfate (PMS) for the degradation of fluorinated pharmaceutical, and we bring about an interesting discovery that light irradiation can change the activation pathway of PMS. Due to the formation of internal electric field, Co 3 O 4 /g-C 3 N 4 composite exhibits very good charge transfer ability and offers more active sites. Thus, Co 3 O 4 /g-C 3 N 4 composite can quickly activate PMS to produce SO 4 •- , achieving effective degradation of ofloxacin with a reaction rate constant as high as 1.6813 min −1 . Once visible light irradiation is introduced, notably, the activation pathway of PMS over Co 3 O 4 /g-C 3 N 4 composite becomes non-radical mechanism based on 1 O 2 , which is mainly ascribed to the generation of O 2 •- . More significantly, anti-interference ability of Co 3 O 4 /g-C 3 N 4 -mediated PMS system is visibly enhanced under the visible light irradiation. To our surprise, consumed electrons of Co 3 O 4 /g-C 3 N 4 composite can be restocked by photogenerated carriers, thereby resulting in the regeneration of catalytic activity. During a long-term operation, Co 3 O 4 /g-C 3 N 4 -mediated PMS system always displays good performance in ofloxacin degradation. In short, current work shared some new insights into the research on the removal of fluorinated pharmaceutical.