Mi Xueyue, Wang Pengfei, Xu Shizhe, Su Lina, Zhong Hui, Wang Haitao, Li Yi, Zhan Sihui
MOE Key Laboratory of Pollution Processes and Environmental Criteria, Tianjin Key Laboratory of Environmental Remediation and Pollution Control, College of Environmental Science and Engineering, Nankai University, Tianjin, 300350, P. R. China.
Tianjin Key Laboratory of Clean Energy and Pollutant Control, School of Energy and Environmental Engineering, Hebei University of Technology, Tianjin, 300401, P. R. China.
Angew Chem Int Ed Engl. 2021 Feb 23;60(9):4588-4593. doi: 10.1002/anie.202014472. Epub 2021 Jan 8.
Single-atom CoN active sites have demonstrated excellent efficiency in peroxymonosulfate activation. However, the identification of CoN active sites and the detailed singlet oxygen generation mechanism in peroxymonosulfate activation remains ambiguous. We demonstrate a strategy to regulate the generation of reactive oxygen species by atomically dispersed cobalt anchored on nitrogen-doped carbon. As indicated by experiment and DFT calculations, CoN was the active site and singlet oxygen was the predominant reactive oxygen species with a proportion of 98.89 %. Spontaneous dissociation of adsorbed peroxymonosulfate on the CoN active sites was energetically unfavorable because of the weakly positive Co atoms and CoN coordination, which directed PMS oxidation by a non-radical pathway and with simultaneous singlet oxygen generation. The generated singlet oxygen degraded several organic pollutants with high efficiency across a broad pH range.
单原子CoN活性位点在过一硫酸盐活化方面已展现出卓越的效率。然而，CoN活性位点的识别以及过一硫酸盐活化过程中详细的单线态氧生成机制仍不明确。我们展示了一种通过锚定在氮掺杂碳上的原子分散钴来调控活性氧生成的策略。实验和密度泛函理论计算表明，CoN是活性位点，单线态氧是主要的活性氧物种，占比为98.89%。由于Co原子呈弱正电性以及CoN配位作用，吸附在CoN活性位点上的过一硫酸盐自发解离在能量上是不利的，这使得过一硫酸盐通过非自由基途径进行氧化并同时生成单线态氧。所生成的单线态氧在较宽的pH范围内高效降解了多种有机污染物。
