Abstract: Heterogeneous metal/carbon material catalysts show great promise in activating peroxymonosulfate (PMS) for advanced wastewater treatment. However, the controllable preparation pathways for highly dispersed metal active centers in modified carbon materials and the mechanistic understanding of PMS activation remain challenging. To address this, this study first utilized cobalt ions to induce the polymerization of aniline monomers, forming highly dispersed Co–N coordination bonds. Subsequently, cobalt-modified nitrogen-doped porous carbon materials (Co-NC) were prepared through pyrolysis carbonization, significantly improving the dispersion of Co active centers on the carbon material surface, thereby effectively enhancing the performance of PMS activation for the degradation of acetaminophen (ACP). Under the optimal Co addition (2 mmol), the prepared Co-NC-2.0 sample could effectively activate PMS, achieving a degradation rate of 99.6% for ACP within 5 min and a chemical oxygen demand (COD) removal rate of 69% within 30 min, and the degradation performance remained unchanged after 5 cycles. Radical trapping experiments and electron paramagnetic resonance spectroscopy confirmed that superoxide radicals (·O₂^–) and singlet oxygen (¹O₂) were mainly generated during the Co-NC-activated PMS process. The mechanistic analysis indicated that the Co-NC material operates through non-radical pathways at the Co active centers, PMS molecules are effectively adsorbed and their O–O bonds are activated and cleaved, generating ·O₂^– and ¹O₂, which subsequently achieve efficient degradation and mineralization of acetaminophen.

Key words: metal monodisperse, polyaniline, porous carbon, peroxymonosulfate, acetaminophen