Insight into the activation of peroxymonosulfate by N-doped copper-based carbon for efficient degradation of organic pollutants:Synergy of nonradicals

The contamination of water resources by phenolic compounds（PCs） presents a significant environmental hazard, necessitating the development of novel materials and methodologies for effective mitigation. In this study, a metallic copper-doped zeolitic imidazolate framework was pyrolyzed and designated as CuNC-20 for the activation of peroxymonosulfate（PMS） to degrade phenol（PE）. Cu-NC-20 could effectively address the issue of metal agglomeration while simultaneously diminishing copper dissolution during the activation of PMS reactions. The Cu-NC-20 catalyst exhibited a rapid degradation rate for PE across a broad p H range（3–9） and demonstrated high tolerance towards coexisting ions. According to scavenger experiments and electron paramagnetic resonance analysis, singlet oxygen（1O2） and high-valent copperoxo(Cu（Ⅲ）) were the predominant reactive oxygen species, indicating that the system was nonradicaldominated during the degradation process. The quantitative structure-activity relationship（QSAR）between the oxidation rate constants of various substituted phenols and Hammett constants was established. It indicated that the Cu-NC-20/PMS system had the optimal oxidation rate constant with σ- correlation and exhibited a typical electrophilic reaction pattern. This study provides a comprehensive understanding of the heterogeneous activation process for the selective removal of phenolic compounds.