Power law for frequency-dependence of double layer capacitance of graphene flakes

• Wang Hongxin

• Aoki Koichi Jeremiah

• Chen Jingyuan

• Nishiumi Toyohiko

• Zeng Xiangdong

• Ma Xiuyuan

抄録

The double layer capacitance per weight of graphene (GN) flakes in aqueous solution at the polarized potential increases with a decrease in the ac-frequency, obeying the inverse of the power law of the frequency. The power law is demonstrated to be equivalent to the constant phase element. The frequency-dependence increases with the thickness of the GN films. Thus, the lower the frequency and the thinner the film is, the larger is the capacitance density per weight. This is confirmed by cyclic voltammetry for several thickness of GN films and several scan rates. Resistance-like voltammograms at thick films are caused by frequencydispersioIEEE TRANSACTIONS ON ELECTRON DEVICESn. The overall capacitive properties of the GN films are as follows: the thickness of one GN flake is estimated to be 2 nm in average from the comparison of the thickness with the capacitances at the HOPG, which is consistent with values by the STM and AFM images.

収録刊行物

• Journal of Electroanalytical Chemistry

  Journal of Electroanalytical Chemistry (741), 114-119, 2015-02

  Elsevier B.V.

キーワード

• Double layer capacitance of graphene films
• Frequency-dispersion
• Constant phase element
• Density of graphene

詳細情報

• CRID: 1571135652664156544
• NII論文ID: 120005541051
• ISSN: 15726657
• Web Site: http://hdl.handle.net/10098/8720
• 本文言語コード: en
• データソース種別:
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