Yan Tingting, Xu Baoxia, Zhang Jianping, Shi Liyi, Zhang Dengsong
Research Center of Nano Science and Technology, Shanghai University Shanghai 200444 China
RSC Adv. 2018 Jan 11;8(5):2490-2497. doi: 10.1039/c7ra10443j. eCollection 2018 Jan 9.
With the development of capacitive deionization technology, charge efficiency and electrosorption capacity have become some of the biggest technical bottlenecks. Asymmetric activated carbon electrodes with ion-selective functional groups inspired by membrane capacitive deionization were developed to conquer these issues. The deionization capacity increased from 11.0 mg g to 23.2 mg g, and the charge efficiency increased from 0.54 to 0.84, due to ion-selective functional groups minimizing the co-ion effect. The charge efficiency and electrosorption capacity resulting from better wettability of these electrodes are effectively enhanced by grafting ion-selective functional groups, which are propitious to ion movement. In addition, asymmetric deionization capacitors show better cycling stability and higher desalination rates. These experimental results have demonstrated that the modification of the ion-selective (oxygen-containing) functional groups on the surfaces of activated carbon could greatly minimize the co-ion effects and increase the salt removal from the solution. These results have indicated that the ion-selective asymmetric carbon electrodes can promote well the development of deionization capacitors for practical desalination.
随着电容去离子技术的发展，电荷效率和电吸附容量已成为一些最大的技术瓶颈。受膜电容去离子启发，开发了具有离子选择性官能团的不对称活性炭电极来克服这些问题。由于离子选择性官能团使共离子效应最小化，去离子容量从11.0毫克/克增加到23.2毫克/克，电荷效率从0.54提高到0.84。通过接枝有利于离子移动的离子选择性官能团，这些电极更好的润湿性有效提高了电荷效率和电吸附容量。此外，不对称去离子电容器表现出更好的循环稳定性和更高的脱盐率。这些实验结果表明，活性炭表面离子选择性（含氧化合物）官能团的改性可极大地减少共离子效应，并增加从溶液中去除盐分。这些结果表明，离子选择性不对称碳电极可很好地促进用于实际脱盐的去离子电容器的发展。
