Understanding the graphene-based electric double layer from dielectric perspective: A density functional study
Understanding the graphene-based electric double layer from dielectric perspective: A density functional study
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DOI：
10.1016/j.cplett.2017.04.006
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发表时间：
2017-06-01
影响因子：
2.8
通讯作者：
Shi, Haosen
中科院分区：
文献类型：
--
作者：
Ma, Ke;Wang, Xuewei;Shi, Haosen
我们将密度泛函计算应用于各层石墨烯基电极附近离子液体的双电层体系。介电屏蔽延伸到电极的内部深处。在石墨烯片上，不均匀的电荷分布表明电极具有高度极化性。通过定义计算量子电容，即多余电荷除以相应的电位位移，验证了由态泛函密度得到的量子电容。在带电界面系统中，费米能级相对于狄拉克点发生位移。与原始石墨烯相比，位移区主要由石墨烯上的投影态密度控制，其形状相当不变。(C) 2017 Elsevier B.V.版权所有
We apply density functional calculations to electrical double layer system of ionic liquids near graphene-based electrode of various layers. Dielectric screening extends deep into the inside of the electrode. Across graphene sheets, non-uniform charge distribution indicates a highly polarizable electrode. The quantum capacitance obtained from density of states functional is validated by calculating quantum capacitance from definition, i.e. dividing excess charges by corresponding potential shift. In systems of charged interface, Fermi level experiences a shift relative to Dirac point. The shift region is dominated by projected density of states on graphene with a rather invariant shape compared to pristine graphene. (C) 2017 Elsevier B.V. All rights reserved.