Real-Time, in Situ Monitoring of the Oxidation of Graphite: Lessons Learned

Naoki Morimoto, Hideyuki Suzuki, Yasuo Takeuchi, Shogo Kawaguchi, Masahiro Kunisu, Christopher W. Bielawski, Yuta Nishina

Research output: Contribution to journalArticle

18 Citations (Scopus)

Abstract

Graphite oxide (GO) and its constituent layers (i.e., graphene oxide) display a broad range of functional groups and, as such, have attracted significant attention for use in numerous applications. GO is commonly prepared using the “Hummers method” or a variant thereof in which graphite is treated with KMnO4 and various additives in H2SO4. Despite its omnipresence, the underlying chemistry of such oxidation reactions is not well understood and typically affords results that are irreproducible and, in some cases, unsafe. To overcome these limitations, the oxidation of graphite under Hummers-type conditions was monitored over time using in situ X-ray diffraction and in situ X-ray absorption near edge structure analyses with synchrotron radiation. In conjunction with other atomic absorption spectroscopy, UV-vis spectroscopy and elemental analysis measurements, the underlying mechanism of the oxidation reaction was elucidated, and the reaction conditions were optimized. Ultimately, the methodology for reproducibly preparing GO on large scales using only graphite, H2SO4, and KMnO4 was developed and successfully adapted for use in continuous flow systems.

Original languageEnglish
Pages (from-to)2150-2156
Number of pages7
JournalChemistry of Materials
Volume29
Issue number5
DOIs
Publication statusPublished - Mar 14 2017

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ASJC Scopus subject areas

  • Chemistry(all)
  • Chemical Engineering(all)
  • Materials Chemistry

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