Cobalt nanoparticles embedded in carbon nanotubes with high specific surface area activate peroxymonosulfate to degrade ciprofloxacin

Advanced oxidation method based on sulfate radical (SO4 center dot- ) are increasingly used to degrade organic pollutants. However, high-efficient and stable catalysts are still needed at this stage. In this study, nitrogen-doped carbon nanotubes coated cobalt nanoparticles (Co@NCNTs) were prepared by a simple and rapid pyrolysis method and employed as a high performance peroxymonosulfate (PMS) activator for degradation of the antibiotic ciprofloxacin (CIP). The Co@NCNTs/PMS system achieved 100 % removal of CIP in 40 min with low metal leaching. The effects of Co@NCNTs on PMS activation under different experimental conditions were investigated. The catalyst maintained excellent catalytic activity in the presence of different anions and humic acids and in a wide pH range (4-9). SO4 center dot- was identified as the active substance primarily responsible for removing CIP. The possible degradation pathway of CIP was proposed by analyzing the degradation intermediates of CIP. This work provides a high-performance catalyst to activate PMS for the removal of antibiotic with low metal leaching.