Graphene shell-encapsulated copper-based nanoparticles (G@Cu-NPs) effectively activate peracetic acid for elimination of sulfamethazine in water under neutral condition

In this study, a graphene shell-encapsulated copper-based nanoparticles (G@Cu-NPs) was prepared and employed for peracetic acid (PAA) activation. The characterization of G@Cu-NPs confirmed that the as-prepared material was composed of Cu0 and Cu2O inside and encapsulated by a graphene shell. Experimental results suggested that the synthesized G@Cu-NPs could activate PAA to generate free radicals for efficiently removing sulfamethazine (SMT) under neutral condition. The formation of graphene shells could strongly facilitated electron transfer from the core to the surface. Radical quenching experiments and electron spin resonance (ESR) analysis confirmed that organic radicals (R-O center dot) and hydroxyl radicals (center dot OH) were generated in the G@Cu-NPs/ PAA system, and R-O center dot (including CH3CO3 center dot and CH3CO2 center dot) was the main contributor to the elimination of SMT. The possible SMT degradation pathways and mechanisms were proposed, and the toxicity of SMT and its in-termediates was predicted with the quantitative structure-activity relationship (QSAR) analysis. Besides, the effects of some key parameters, common anions, and humic acid (HA) on the removal of SMT in the G@Cu-NPs/ PAA system were also investigated. Finally, the applicability of G@Cu-NPs/PAA system was explored, showing that the G@Cu-NPs/PAA system possessed satisfactory adaptability to treat different water bodies with admi-rable reusability and stability.

Automated summary

In this study, graphene shell-encapsulated copper-based nanoparticles (G@Cu-NPs) were prepared for peracetic acid (PAA) activation, leading to efficient removal of sulfamethazine (SMT). The graphene shells facilitated electron transfer and generated organic radicals and hydroxyl radicals, which played a crucial role in removing SMT. The research also proposed possible degradation pathways and mechanisms, and predicted the toxicity of SMT and its intermediates. The effects of key parameters, common anions, and humic acid on the removal of SMT were investigated. The G@Cu-NPs/PAA system showed promising adaptability, reusability, and stability in treating different water bodies.