Efficient degradation and mineralization of antibiotics via heterogeneous activation of peroxymonosulfate by using graphene supported single-atom Cu catalyst

Single metal catalysts build a bridge between homogeneous catalysis and heterogeneous catalysis. Herein, we report the single-atom copper sites embedded in reduced graphene oxide (SA-Cu/rGO) for the degradation of various antibiotics, including sulfamethoxazole (SMX), meropenem and sulfafurazole via the heterogeneous activation of peroxymonosulfate (PMS). The SA-Cu/rGO/PMS system exhibited an enhanced performance toward the degradation of SMX with the kinetic was ~3.9 times faster than in the rGO/PMS system. Strikingly, we found that over 99% of the total organic carbon (TOC) was eliminated in the SA-Cu/rGO/PMS system within 120 min, demonstrating its excellent mineralization ability. The enhanced catalytic performance could be due to the synergistic effect between the rGO matrix and the exposed Cu active sites, which facilitated the generation large amount of reactive species and the in-situ decomposition of the pollutants at the surface of the catalysts. This SA-Cu/rGO catalyst with multifunctional properties can be potentially applied in the treatment of refractory wastewater.