Peng Yiyin, Bian Zhaoyong, Wang Feng, Li Shunlin, Xu Shiwei, Wang Hui
College of Water Sciences, Beijing Normal University, Beijing 100875, PR China.
College of Water Sciences, Beijing Normal University, Beijing 100875, PR China.
J Hazard Mater. 2024 Jan 15;462:132797. doi: 10.1016/j.jhazmat.2023.132797. Epub 2023 Oct 16.
Although metal-free electrodes in molecular oxygen-activated Fenton-like wastewater treatment technologies have been developed, the reactive oxygen species (ROS) generation mechanisms are still not sufficiently clear. As a typical example of refractory phenolic wastewater, p-nitrophenol (PNP) has been widely studied. This study demonstrated the critical role of superoxide radicals (O) in PNP degradation by metal-free electrodes through electron spin resonance (ESR), ROS quenching, and density functional theory (DFT) tests. The most superior metal-free electrode exhibited a mass activity of approximately 133.5 h g. Experimental and theoretical studies revealed the mechanism of O generation via oxygen activation, including one- and three-electron transfer pathways, and found that O mainly attacked the nitro group of PNP to degrade and transform the pollutant. This study enhances the mechanistic understanding of metal-free materials in the electrochemical degradation of refractory pollutants.
尽管在分子氧活化类芬顿废水处理技术中已开发出无金属电极，但活性氧物种（ROS）的产生机制仍不够清晰。作为难处理酚类废水的典型例子，对硝基苯酚（PNP）已得到广泛研究。本研究通过电子自旋共振（ESR）、ROS猝灭和密度泛函理论（DFT）测试，证明了超氧自由基（O）在无金属电极降解PNP中的关键作用。最优异的无金属电极表现出约133.5 h g的质量活性。实验和理论研究揭示了通过氧活化产生O的机制，包括单电子和三电子转移途径，并发现O主要攻击PNP的硝基以降解和转化污染物。本研究增进了对无金属材料在难处理污染物电化学降解中机制的理解。
