期刊
ELECTROCHEMISTRY COMMUNICATIONS
卷 38, 期 -, 页码 44-46出版社
ELSEVIER SCIENCE INC
DOI: 10.1016/j.elecom.2013.10.027
关键词
Ionic liquid; Differential capacitance; Electric double layer; Specific adsorption; Potential of zero charge
资金
- NSFC [21373118, 21073097, 51102137]
- ABC 973 [2009CB220100]
- Natural Science Foundation of Tianjin [12JCYBJC13900]
- [NCET-10-0512]
The differential capacitance/potential curves of two ionic liquid (IL) electrolytes, 1-butyl-3-methyl-imidazolium hexafluorophosphate (BMIM+/PF6- and N-butyl-N-methyl-pyrrolidinium hexafluorophosphate (Pyr(14)(+)/PF6-) on a glassy carbon (GC) electrode were measured experimentally. The differential capacitance of BMIM+/PF6-/GC is higher in the negative polarization, while the differential capacitance of Pyr(14)(+)/PF6-/GC is higher in the positive polarization, although both ILs are composed of common anions, with cations of similar ionic structures and diameters. Such an opposite trend may be understood in terms of the specific adsorption between BMIM and the GC electrode, caused by the pi-stacking interaction between the aromatic imidazolium ring and the sp(2) graphite surface. The specific adsorption effectively shortens the electric double layer (EDL) thickness on the negatively charged electrode but elongates the EDL thickness on the positively charged electrode. Such an effect is manifested in the differential capacitance, with a higher value on the negative polarization branch than on the positive polarization branch. The impact of the specific adsorption is also seen from the positive shift of the potential of zero charge of BMIM+/PF6-/GC in comparison with that of Pyr(14)(+)/PF6-/GC. (C) 2013 Elsevier B.V. All rights reserved.
作者
我是这篇论文的作者
点击您的名字以认领此论文并将其添加到您的个人资料中。
推荐
暂无数据