Co-ZIF reinforced cow manure biochar (CMB) as an effective peroxymonosulfate activator for degradation of carbamazepine

Excessive emissions of cow manure have put tremendous pressure on environment, the difficulties in disposal methods have presented serious challenges to the livestock industry. Herein, cow manure biochar (CMB) loaded metal-organic framework (ZIF-67) precursors derived Co nanoparticles carbon (Co@NPC) at different temperatures to form biochar-based composites, i.e., Co@NPC-CMB-x. The novel non-homogeneous catalysts activated peroxymonosulfate (PMS) to degrade the carbamazepine (CBZ). The results demonstrated that the pyrolysis temperature directly influenced the intrinsic properties and catalytic ability of products, with the higher pyrolysis temperature favoring the conversion of more graphitic C and graphitic N as active sites. In particular, Co@NPC-CMB-800 showed excellent activation of PMS, degrading 100% CBZ within 30 min. The high specific surface area, highly graphitic structure and the uniform dispersion of cobalt species were the key reasons for the excellent catalytic ability. X-ray photoelectron spectroscopy (XPS) illustrated that the interaction between biochar and transition metal was responsible to generate more reactive oxygen species. Furthermore, electron paramagnetic resonance (EPR) confirmed that non-radical singlet oxygen is the dominant pathway for CBZ degradation by the catalyst. This study provides a new strategy for cow manure application in functional catalysts and offers new prospects for designing efficient biochar-based catalysts for environmental remediation.