College of Environment, Zhejiang University of Technology, Hangzhou, 310032, China.
College of Environment, Zhejiang University of Technology, Hangzhou, 310032, China.
Chemosphere. 2021 Jan;263:128069. doi: 10.1016/j.chemosphere.2020.128069. Epub 2020 Aug 28.
In this study, the CNTs were successfully compounded in PbO electrode through composite electrodeposition technology to obtain multi-layer CNT-PbO electrode. Scanning electron microscope, X-ray diffraction and X-ray Photoelectron Spectroscopy were comprehensively used to characterize the lead dioxide electrode and the electrochemical performance were also tested by cyclic voltammetry, and electrochemical impedance spectroscopy. Results showed that CNT-PbO significantly improved the electrochemical performance, which was attributed to that the compound of CNTs in PbO improved the active sites on the surface, with higher oxidation peaks, smaller particle size, larger specific surface area, and lower charge transfer resistance. In the degradation experiment, the chemical oxygen demand removal efficiency of isoniazid by CNT-PbO electrode were 1.37 times of that by pure PbO electrode. The main influence factors on the degradation of ISN, such as initial ISN concentration, NaSO concentration, current density and initial pH value was analyzed in detail. Considered comprehensively the effects of ISN removal efficiency, COD and average current efficiency, the degradation of ISN and COD reached 99.4% and 86.8%, respectively, after the electrode was degraded by electrochemical oxidation for 120 min under the best conditions. In addition, the degradation mechanism of ISN in electrochemical oxidation was studied. According to the intermediate products detected by GC-MS, the possible degradation pathway of ISN in electrochemical oxidation system were proposed.
在这项研究中，通过复合电沉积技术成功地将 CNT 复合到 PbO 电极中，得到了多层 CNT-PbO 电极。综合使用扫描电子显微镜、X 射线衍射和 X 射线光电子能谱对二氧化铅电极进行了表征，并通过循环伏安法和电化学阻抗谱测试了其电化学性能。结果表明，CNT-PbO 显著提高了电化学性能，这归因于 CNTs 的复合在表面上增加了活性位点，具有更高的氧化峰、更小的粒径、更大的比表面积和更低的电荷转移电阻。在降解实验中，CNT-PbO 电极对异烟肼的化学需氧量去除效率是纯 PbO 电极的 1.37 倍。详细分析了影响 ISN 降解的主要因素，如初始 ISN 浓度、NaSO 浓度、电流密度和初始 pH 值。综合考虑 ISN 去除效率、COD 和平均电流效率，在最佳条件下，电极经电化学氧化 120 分钟后，ISN 和 COD 的降解分别达到 99.4%和 86.8%。此外，还研究了电化学氧化中 ISN 的降解机制。根据 GC-MS 检测到的中间产物，提出了电化学氧化体系中 ISN 可能的降解途径。
