Abstract：
Significant efforts have recently been exerted toward construction of singlet oxygen (1O2)-dominated catalytic oxidation systems for selective removal of organic contaminants from wastewater, with peroxides serving as the chemical source. However, the relevance of 1O2 in the removal of pollutants remains ambiguous and requires elucidation. In this study, we scrupulously exclude the significant role of 1O2 in contaminant degradation in various peroxymonosulfate (PMS) activation systems. Multiple experimental results indicate that the activation of PMS catalyzed by CuO, MnO2, Fe-doped g-C3N4 (Fe-CN), or N-doped graphite does not predominantly follow the 1O2 pathway. More importantly, the reactivity of 1O2 is remarkably overestimated in the literature, given its inferior capacity in degradation of a range of heterocyclic contaminants and aromatic compounds possessing electron-withdrawing groups. In addition, the strong physical quenching effect of water, coupled with the low oxidizing ability of 1O2, would notably reduce the utilization efficiency of peroxide, which is particularly apparent in the degradation of micropollutants. We reckon that this study is expected to end the long-running dispute associated with the relevance of 1O2 in pollutant removal.
摘要：
最近在构建单线态氧（1O2）为主的催化氧化系统方面做出了巨大的努力，以选择性地去除废水中的有机污染物。过氧化物作为化学来源。然而,1O2在去除污染物中的相关性仍然模棱两可，需要阐明。在这项研究中,我们严格排除了各种过氧单硫酸盐（PMS）活化系统中1O2在污染物降解中的重要作用。多个实验结果表明,CuO催化PMS活化,MnO2,Fe掺杂g-C3N4(Fe-CN),或N掺杂石墨不主要遵循1O2途径。更重要的是,1O2的反应性在文献中被大大高估了，鉴于其降解一系列杂环污染物和具有吸电子基团的芳族化合物的能力较差。此外,水的强烈物理淬火作用，再加上1O2的氧化能力低，会显著降低过氧化物的利用效率，这在微污染物的降解中尤为明显。我们认为，这项研究有望结束与1O2在污染物去除中的相关性有关的长期争议。
