Porous 3D superstructure of nitrogen doped carbon decorated with ultrafine cobalt nanodots as peroxymonosulfate activator for the degradation of sulfonamides

Abstract Superstructures have attracted attention because of their potential applications in chemistry and materials science. In this work, we report the preparation of a porous 3D superstructure of nitrogen-doped carbon decorated with ultrafine cobalt nanodots (Co@NCSS) derived from the self-assembly of polyimide nanoparticles. Utilizing modified ultra-small cobalt nanodots as main catalytically active sites, and the excellent quality and electron transport efficiency generated by this 3D porous superstructure, Co@NCSS exhibited excellent catalytic performance as a peroxymonosulfate (PMS) activator towards the degradation of several sulfonamides. Based on radical scavenging tests and electron paramagnetic resonance (EPR), singlet oxygen (1O2) was the dominant oxidative species. Furthermore, through the identification of degradation intermediates by HPLC-MS and DFT calculation, the pathway of sulfamethoxazole (SMX) degradation by Co@NCSS/PMS was analyzed. The possible catalytic mechanism of Co@NCSS/PMS for SMX degradation is also proposed in this paper. Co@NCSS has the potential to be an ideal material for removing antibiotics from wastewater.