Co nanoparticles encapsulated in nitrogen-doped nanocarbon derived from cobalt-modified covalent organic framework as peroxymonosulfate activator for sulfamerazine degradation

In this work, new covalent organic framework (COF) materials with high crystallinity and large specific surface areas were used as cobalt-loaded supports. Cobalt nanoparticle-embedded nitrogen-doped carbon porous catalysts ([email protected]) were obtained by high-temperature pyrolysis of the COF materials and cobalt salts. With multiple active sites (Co0, pyridine N, and graphitic N), [email protected] exhibited superior catalytic properties for peroxymonosulfate (PMS) activation toward the degradation of sulfamerazine (SMZ). The efficiency of SMZ degradation reached 92.4 % within 10 min and the total organic carbon (TOC) removal rate reached 70.3 % within 30 min. Using radical quenching experiments and electron paramagnetic resonance (EPR) analysis, sulfate radicals (SO4•−), hydroxyl radicals (•OH), and singlet oxygen (1O2) were identified in this system, while 1O2 was the dominant active species for SMZ removal. The degradation intermediates of SMZ in [email protected]/PMS were monitored by high performance liquid chromatography–time of flight mass spectrometry (HPLC–TOFMS).