Tang Mengdi, Zhang Yonggang
State Key Laboratory of Separation Membranes and Membrane Processes, Tiangong University Tianjin 300387 China
School of Environmental Science and Engineering, Tiangong University Tianjin 300387 China.
RSC Adv. 2021 Nov 25;11(60):38003-38015. doi: 10.1039/d1ra06691a. eCollection 2021 Nov 23.
Degradation of nonbiodegradable organic compounds into harmless substances is one of the main challenges in environmental protection. Electrically-activated persulfate process has served as an efficient advanced oxidation process (AOP) to degrade organic compounds. In this study, we synthesized three nitrogen-doped carbon materials, namely, nitrogen-doped activated carbon plus graphene (NC), and nitrogen-doped activated carbon (NAC), nitrogen-doped graphene (NGE), and three nitrogen-doped carbon material-graphite felt (GF) cathodes. The three nitrogen-doped carbon materials (NC, NGE, NAC) were characterized using X-ray diffraction, Raman spectroscopy, X-ray electron spectroscopy, and nitrogen desorption-adsorption. The electron spin resonance technique was used to identify the presence of hydroxyl radicals (˙OH), sulfate radicals (SO˙) and singlet oxygen (O) species. The results showed that NC was more conducive for the production of free radicals. In addition, we applied NC-GF to an electro-activated persulfate system with the degradation of -nitrophenol and investigated its performance for contaminant degradation under different conditions. In general, the nitrogen-doped carbon electrode electro-activated persulfate process is a promising way to treat organic pollutants in wastewater.
将不可生物降解的有机化合物降解为无害物质是环境保护中的主要挑战之一。电活化过硫酸盐工艺已成为一种降解有机化合物的高效高级氧化工艺（AOP）。在本研究中，我们合成了三种氮掺杂碳材料，即氮掺杂活性炭加石墨烯（NC）、氮掺杂活性炭（NAC）、氮掺杂石墨烯（NGE），以及三种氮掺杂碳材料-石墨毡（GF）阴极。利用X射线衍射、拉曼光谱、X射线电子能谱和氮脱附-吸附对三种氮掺杂碳材料（NC、NGE、NAC）进行了表征。采用电子自旋共振技术鉴定羟基自由基（˙OH）、硫酸根自由基（SO˙）和单线态氧（O）物种的存在。结果表明，NC更有利于自由基的产生。此外，我们将NC-GF应用于电活化过硫酸盐体系中降解对硝基苯酚，并研究了其在不同条件下对污染物的降解性能。总体而言，氮掺杂碳电极电活化过硫酸盐工艺是处理废水中有机污染物的一种有前景的方法。
