Enhancement of capacitance by electrochemical oxidation of nanodiamond derived carbon nano-onions

Yiyang Liu, Doo Young Kim

Research output: Contribution to journalArticlepeer-review

31 Scopus citations


Electrode responsiveness and electrochemical capacitance behavior of nanodiamond-derived carbon nano-onions (N-CNOs) were studied. N-CNOs were prepared by thermal annealing of nanodiamond powders. A thin film of N-CNOs was mounted on glassy carbon (GC) current collector and showed an excellent electrochemical behavior with rectangular voltammetric curves as well as great scan rate dependence of capacitance. The capacitance showed negligible drops over a wide range of scan rates (50 mV/s - 5 V/s) in both KCl and H 2SO4. This excellent capacitive behavior was attributed to good electrical conductivity and mesoporous nature of N-CNOs. In order to further enhance capacitance, electrochemical oxidation of N-CNOs was carried out by iterating anodic cycling in acidic electrolytes. The capacitance enhancement of oxidized N-CNOs was probed by cyclic voltammetry as well as galvanostatic charging-discharging measurement. This study demonstrates that electrochemical oxidation can be an effective method to improve capacitance and energy density of carbon nanomaterials while maintaining a good scan rate performance.

Original languageEnglish
Pages (from-to)82-87
Number of pages6
JournalElectrochimica Acta
StatePublished - Sep 1 2014

Bibliographical note

Funding Information:
This research was supported by the University of Kentucky faculty start-up grant. The authors acknowledge NSF for the use of the recently installed XPS at the University of Kentucky. The purchase of the XPS was supported by the funds from NSF EPSCoR (grant No. 0814194).


  • capacitance
  • carbon nano-onions
  • electrochemical oxidation
  • nanodiamond

ASJC Scopus subject areas

  • General Chemical Engineering
  • Electrochemistry


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