Salt-assisted direct exfoliation of graphite into high-quality, large-size, few-layer graphene sheets

Liyong Niu, Mingjian Li, Xiaoming Tao, Zhuang Xie, Xuechang Zhou, Arun P.A. Raju, Robert J. Young, Zijian Zheng

Research output: Journal article publicationJournal articleAcademic researchpeer-review

65 Citations (Scopus)

Abstract

We report a facile and low-cost method to directly exfoliate graphite powders into large-size, high-quality, and solution-dispersible few-layer graphene sheets. In this method, aqueous mixtures of graphite and inorganic salts such as NaCl and CuCl2are stirred, and subsequently dried by evaporation. Finally, the mixture powders are dispersed into an orthogonal organic solvent solution of the salt by low-power and short-time ultrasonication, which exfoliates graphite into few-layer graphene sheets. We find that the as-made graphene sheets contain little oxygen, and 86% of them are 1-5 layers with lateral sizes as large as 210 μm2. Importantly, the as-made graphene can be readily dispersed into aqueous solution in the presence of surfactant and thus is compatible with various solution-processing techniques towards graphene-based thin film devices.
Original languageEnglish
Pages (from-to)7202-7208
Number of pages7
JournalNanoscale
Volume5
Issue number16
DOIs
Publication statusPublished - 21 Aug 2013

ASJC Scopus subject areas

  • Materials Science(all)

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