ZIF-8-derived nitrogen-doped porous carbon supported CuFeO2 for sulfamethoxazole removal: Performances, degradation pathways and mechanisms

The magnetic CuFeO 2 anchored on nitrogen-doped porous carbon (CuFeO 2 /NC) hybrid catalysts were further synthesized via hydrothermal reaction without the addition of a chemical reductant. The systematic CuFeO 2 /NC with larger specific surface areas (SSAs) and abundant active sites exhibited strong adsorption ability and great catalytic performance towards activating peroxymonosulfate (PMS) for sulfamethoxazole (SMX) removal. It was noted that 18 mg/L SMX was completely removed after 40 min of pre-adsorption and 30 min of oxidative degradation in CuFeO 2 /NC and PMS system. The degradation rate constant ( k ) was calculated by fitting as 0.166 min −1 , being about 7.9 times that in the CuFeO 2 and PMS system (0.021 min −1 ). The SO 4 · - ,·OH, and 1 O 2 as the dominant reactive oxygen species (ROSs) contributed to sulfamethoxazole degradation. The N species, active oxygen and the redox cycles of Cu(Ⅱ)/Cu(Ⅰ) and Fe(Ⅲ)/Fe(Ⅱ) were confirmed to play a vital role in the activation of PMS for the generation of ROSs. Based on the LC-MS analysis, the possible degradation routes of SMX in the PMS activation system by CuFeO 2 /NC were proposed.