CoFe2O4 nanoparticles assembled on natural sepiolite fibers as peroxymonosulfate catalyst for efficient norfloxacin degradation

In this work, CoFe 2 O 4 /Sepiolite catalysts were successfully synthesized via a water bath-calcination method. The composite performed greatly enhanced norfloxacin (NOR) degradation activity by activating PMS, and the reaction rate constant was about 6.31 times higher than that of bare CoFe 2 O 4 . This was mainly attributed to the introduction of sepiolite support leading to higher adsorption capacity, more exposed reaction active sites due to the formation of CoFe 2 O 4 nanoparticles with smaller grain size. The EPR and quenching experiments indicated that SO 4 •− and 1 O 2 were the main major contributors for NOR degradation. The redox cycle of Co 2+ /Co 3+ and Fe 2+ /Fe 3+ were mainly responsible for the continuous generation of reaction active species thereby achieving the efficient NOR degradation. Moreover, the enhanced catalytic mechanisms and NOR degradation pathways in CoFe 2 O 4 /Sepiolite/PMS system were further proposed. Overall, this study provides a new insight for the rational design of mineral-based PMS catalysts for efficient wastewater treatment.