File Download

There are no files associated with this item.

  • Find it @ UNIST can give you direct access to the published full text of this article. (UNISTARs only)
Related Researcher

DingFeng

Ding, Feng
Read More

Views & Downloads

Detailed Information

Cited time in webofscience Cited time in scopus
Metadata Downloads

Sequential Electrochemical Unzipping of Single-Walled Carbon Nanotubes to Graphene Ribbons Revealed by in Situ Raman Spectroscopy and Imaging

Author(s)
John, RobinShinde, Dhanraj B.Liu, LiliDing, FengXu, ZhipingVijayan, CherianathPillai, Vijayamohanan K.Pradeep, Thalappil
Issued Date
2014-01
DOI
10.1021/nn403289g
URI
https://scholarworks.unist.ac.kr/handle/201301/31341
Fulltext
https://pubs.acs.org/doi/10.1021/nn403289g
Citation
ACS NANO, v.8, no.1, pp.234 - 242
Abstract
We report an in situ Raman spectroscopic and microscopic investigation of the electrochemical unzipping of single-walled carbon nanotubes (SWNTs). Observations of the radial breathing modes (RBMs) using Raman spectral mapping reveal that metallic SWNTs are opened up rapidly followed by gradual unzipping of semiconducting SWNTs. Consideration of the resonant Raman scattering theory suggests that two metallic SWNTs with chiralities (10,4) and (12, 0) get unzipped first at a lower electrode potential (036 V) followed by the gradual unzipping of another two metallic tubes, (9, 3) and (10, 1), at a relatively higher potential (1.16 V). The semiconducting SWNTs with chiralities (11, 7) and (12, 5), however, get open up gradually at +/- 1.66 V. A rapid decrease followed by a subsequent gradual decrease in the metallicity of the SWNT ensemble as revealed from a remarkable variation of the peak width of the G band complies well with the variations of RBM. Cyclic voltammetry also gives direct evidence for unzipping in terms of improved capacitance after oxidation followed by more important removal of oxygen functionalities during the reduction step, as reflected in subtle changes of the morphology confirming the formation of graphene nanoribbons. The density functional-based tight binding calculations show additional dependence of chirality and diameter of nanotubes on the epoxide binding energies, which is in agreement with the Raman spectroscopic results and suggests a possible mechanism of unzipping determined by combined effects of the structural characteristics of SWNTs and applied field.
Publisher
AMER CHEMICAL SOC
ISSN
1936-0851
Keyword (Author)
graphenesingle-walled carbon nanotubeselectrochemistryRaman spectral mappingdensity functional-based tight binding calculations
Keyword
TRANSISTORSSEPARATIONSHAPE

qrcode

Items in Repository are protected by copyright, with all rights reserved, unless otherwise indicated.