College of Environmental Science and Engineering and Key Laboratory of Environmental Biology and Pollution Control (Ministry of Education), Hunan University, Changsha, 410082, P. R. China.
Department of Chemical and Materials Engineering, University of Alberta, Edmonton, Alberta, T6G 1H9, Canada.
Small. 2024 Aug;20(32):e2311552. doi: 10.1002/smll.202311552. Epub 2024 Mar 19.
The activation of persulfates to degrade refractory organic pollutants is a hot issue in advanced oxidation right now. Here, it is reported that single-atom Fe-incorporated carbon nitride (Fe-CN-650) can effectively activate peroxymonosulfate (PMS) for sulfamethoxazole (SMX) removal. Through some characterization techniques and DFT calculation, it is proved that Fe single atoms in Fe-CN-650 exist mainly in the form of Fe-NO coordination, and Fe-NO exhibited better affinity for PMS than the traditional Fe-N structure. The degradation rate constant of SMX in the Fe-CN-650/PMS system reached 0.472 min, and 90.80% of SMX can still be effectively degraded within 10 min after five consecutive recovery cycles. The radical quenching experiment and electrochemical analysis confirm that the pollutants are mainly degraded by two non-radical pathways through O and Fe(IV)═O induced at the Fe-NO sites. In addition, the intermediate products of SMX degradation in the Fe-CN-650/PMS system show toxicity attenuation or non-toxicity. This study offers valuable insights into the design of carbon-based single-atom catalysts and provides a potential remediation technology for the optimum activation of PMS to disintegrate organic pollutants.
过硫酸盐活化降解难降解有机污染物是当前高级氧化领域的一个热点问题。本文报道了单原子铁嵌入氮化碳（Fe-CN-650）可以有效地活化过一硫酸盐（PMS）去除磺胺甲恶唑（SMX）。通过一些表征技术和 DFT 计算，证明了 Fe-CN-650 中的 Fe 单原子主要以 Fe-NO 配位的形式存在，并且 Fe-NO 与 PMS 的亲和力优于传统的 Fe-N 结构。在 Fe-CN-650/PMS 体系中，SMX 的降解速率常数达到 0.472 min，在连续五次回收循环后，10 分钟内仍能有效降解 90.80%的 SMX。自由基猝灭实验和电化学分析证实，污染物主要通过在 Fe-NO 位点诱导的 O 和 Fe(IV)═O 通过两种非自由基途径降解。此外，在 Fe-CN-650/PMS 体系中，SMX 降解的中间产物表现出毒性减弱或无毒。本研究为基于碳的单原子催化剂的设计提供了有价值的见解，并为 PMS 的最佳活化提供了一种潜在的修复技术，以分解有机污染物。
