Synthesis of CoFe2O4/natural kaolin activated peroxymonosulfate for visible light degradation of organic contaminants

This experiment used a one-step hydrothermal method to prepare a cobalt ferrite/natural kaolin composite catalyst to activate peroxymonosulfate (PMS) to degrade methylene blue, ciprofloxacin, phenol under visible light. The experimental results show that the two-way catalytic system exhibits excellent photocatalytic effects (MB 98%, CPFX 86.3%, phenol 86.9%; 150min). The composite catalyst was characterized by XRD, SEM, XPS, PL, etc. Furthermore, the composite catalyst has a more vital PMS activation ability than bare CoFe2O4. We reported that, in the CF/K + PMS dual-effect synergistic system, CF/K enables to effectively activate PMS in contaminant solutions with no sulfate radical generation. Moreover, MB's degradation efficiency was negligibly affected by the robust acidic or alkaline environment. The influences of different anions on the catalytic reaction, such as Cl−, HCO3−, and NO3− were also investigated. The results show that these ions have no significant effect on catalyst activity. In addition, the free radical quenching experiment combined with XPS analysis confirmed that O21 and holes (h+) play a significant role in MB degradation, rather than SO4−• and •OH. The composite catalyst has good stability; after five rounds of repeated use experiments, the catalyst can still maintain a reasonable degradation rate.