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

Abstract

Advanced oxidation method based on sulfate radical (SO4−) 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– 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.