Facile ball milling preparation of sulfur-doped carbon as peroxymonosulfate activator for efficient removal of organic pollutants

Abstract

Novel sulfur-doped activated carbon (SACx) particles were prepared by a facile ball milling process of a mixture of elemental sulfur and activated carbon (AC), and employed as activators of peroxymonosulfate (PMS) for the degradation of organic pollutants. The SACx/PMS system could efficiently degrade different pollutants including diethyl phthalate, bisphenol A, sulfamethoxazole, and phenol, achieving a degradation efficiency of 60–100% within 120 min. Increasing the S doping content favored PMS activation and pollutant degradation: the DEP degradation rate increased by 9 times as the S-doped content increased from 0 to 8.69 at%. EPR and radical quenching experiments suggested that •OH rather than SO4•− was the dominant reactive species for DEP degradation. The concentration of free radicals was strongly dependent on the content of C–S–C bonds, indicating that these linkages were the main active sites for PMS activation. This study provides a simple but effective strategy to improve the catalytic performance of carbon-based materials as PMS activators to degrade pollutants.