Reinforced degradation of ibuprofen with MnCo2O4/FCNTs nanocatalyst as peroxymonosulfate activator: Performance and mechanism

In order to efficiently degrade ibuprofen (IBU) by peroxymonosulfate (PMS) activation, manganese cobalt oxide nanoparticles-decorated functionalized multi-walled carbon nanotubes (MnCo 2 O 4 /FCNTs) were prepared using a facile hydrothermal method. Comprehensive characterization of this PMS activator in multi-scale suggested that MnCo 2 O 4 nanoparticles were uniformly decorated on FCNTs. The catalytic performance was systematical evaluated under various environmental conditions, including temperature, pH, and the presence of different common water matrix species (e.g., Cl - , HCO 3 - , and natural organic matter). The as-synthesized MnCo 2 O 4 /FCNTs demonstrated excellent catalytic activity with k app ranging 0.285–0.327 min −1 under a wide pH range of 3–9 within 10 min, which achieved a complete removal of IBU and a mineralization rate higher than 90%. During oxidation process for stability and reusability test, recycled MnCo 2 O 4 /FCNTs was found durable with negligible leaching of metal ions from spent catalyst, exhibiting its high stability for PMS activation with merely slight decrease of k app from 0.285 to 0.201 min −1 in the fourth cycle. Electron paramagnetic resonance analysis further confirmed that • OH, SO 4 •- and 1 O 2 were generated in the robust MnCo 2 O 4 /FCNTs-PMS system. Both radical and nonradical reactions were found to be responsible for the enhanced IBU degradation. Overall, this study sheds light on practical knowledge of IBU removal using MnCo 2 O 4 /FCNTs for PMS activation.