| Graphenes prepared by Staudenmaier, Hofmann and Hummers methods with consequent thermal exfoliation exhibit very different electrochemical properties. | |
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MedLine Citation:
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PMID: 22535381 Owner: NLM Status: Publisher |
Abstract/OtherAbstract:
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Large-scale fabrication of graphene is highly important for industrial and academic applications of this material. The most common large-scale preparation method is the oxidation of graphite to graphite oxide using concentrated acids in the presence of strong oxidants and consequent thermal exfoliation and reduction by thermal shock to produce reduced graphene. These oxidation methods typically use concentrated sulfuric acid (a) in combination with fuming nitric acid and KClO(3) (Staudenmaier method), (b) in combination with concentrated nitric acid and KClO(3) (Hofmann method) or (c) in the absence of nitric acid but in the presence of NaNO(3) and KMnO(4) (Hummers method). The evaluation of quality and applicability of the graphenes produced by these various methods is of high importance and is attempted side-by-side for the first time in this paper. Full-scale characterization of thermally reduced graphenes prepared by these standard methods was performed with techniques such as transmission and scanning electron microscopy, Raman spectroscopy and X-ray photoelectron spectroscopy. Their applicability for electrochemical devices was further evaluated by means of cyclic voltammetry techniques. We showed that while Staudenmaier and Hofmann methods (methods that do not use potassium permanganate as oxidant) generated thermally reduced graphenes with comparable electrochemical properties, the graphene prepared by the Hummers method which uses permanganate as oxidant showed higher heterogeneous electron transfer rates and lower overpotentials as compared to graphenes prepared by the Staudenmaier or Hofmann methods. This clearly shows that the methods of preparations have dramatic influences on the materials properties and, thus, such findings are of eminent importance for practical applications as well as for academic research. |
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Authors:
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Hwee Ling Poh; Filip Saněk; Adriano Ambrosi; Guanjia Zhao; Zdeněk Sofer; Martin Pumera |
Publication Detail:
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Type: JOURNAL ARTICLE Date: 2012-4-26 |
Journal Detail:
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Title: Nanoscale Volume: - ISSN: 2040-3372 ISO Abbreviation: - Publication Date: 2012 Apr |
Date Detail:
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Created Date: 2012-4-26 Completed Date: - Revised Date: - |
Medline Journal Info:
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Nlm Unique ID: 101525249 Medline TA: Nanoscale Country: - |
Other Details:
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Languages: ENG Pagination: - Citation Subset: - |
Affiliation:
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Division of Chemistry & Biological Chemistry, School of Physical and Mathematical Sciences, Nanyang Technological University, 637371Singapore. pumera@ntu.edu.sg. |
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From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine
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