Nanotechnology Research Center, Sultan Qaboos University, P.O. Box 33, Al-Khoudh, Muscat 123, Oman.
Department of Physics, College of Science, Sultan Qaboos University, P.O. Box 36, Al-Khoudh, Muscat 123, Oman.
J Hazard Mater. 2020 Mar 5;385:121565. doi: 10.1016/j.jhazmat.2019.121565. Epub 2019 Nov 4.
Activated carbon cloth (ACC) coated with zinc oxide (ZnO) nanoparticles (NPs) have been used as electrodes in flow-by capacitive deionization (CDI) system. Aqueous solution of individual Pb and Cd ions and mixed Pb and Cd ions were used as test contaminant in CDI system to study the effect of surface modification upon ions removal efficiency. Due to the aggregated structure of ZnO NPs on ACC surface, the modified ACC electrodes develop the additional surface area as well as dielectric barrier therefore resulting in higher specific capacitance. In addition, coating with ZnO NPs effectively reduced physical adsorption whereby enhanced the ions adsorption rate and capacity during electrosorption process. Upon incorporating with ZnO NPs, the electrosorption efficiency was enhanced from 17% to 33% for Pb, from 21% to 29% for Cd and from 21% to 35% for mixed Pb and Cd ions. The power consumption of individual ions and mixed ions removal process for ACC and ZnO NPs modified ACC were also discussed. Furthermore, used ACC electrodes surfaces were examined using photoelectron spectroscopy (XPS) and results were also conferred. The CDI ACC electrodes with ZnO NPs showed a promising and an effective way for heavy metal removal applications.
负载氧化锌纳米粒子（NPs）的活性炭布（ACC）已被用作流动电容去离子（CDI）系统中的电极。采用单独的 Pb 和 Cd 离子水溶液以及混合的 Pb 和 Cd 离子水溶液作为 CDI 系统中的测试污染物，研究了表面改性对离子去除效率的影响。由于 ZnO NPs 在 ACC 表面的聚集结构，改性后的 ACC 电极增加了比表面积和介电阻挡层，从而提高了比电容。此外，负载 ZnO NPs 可以有效减少物理吸附，从而提高了电吸附过程中的离子吸附速率和容量。负载 ZnO NPs 后，对于 Pb，电吸附效率从 17%提高到 33%，对于 Cd，从 21%提高到 29%，对于混合的 Pb 和 Cd 离子，从 21%提高到 35%。还讨论了 ACC 和 ZnO NPs 改性 ACC 去除单个离子和混合离子的过程中的能耗。此外，还使用光电能谱（XPS）对使用过的 ACC 电极表面进行了检查，并给出了结果。结果表明，负载 ZnO NPs 的 CDI ACC 电极是一种很有前途且有效的去除重金属的方法。
