title: High-yield production of graphene by liquid-phase exfoliation of graphite.
abstract: Fully exploiting the properties of graphene will require a method for the mass production of this remarkable material. Two main routes are possible: large-scale growth or large-scale exfoliation. Here, we demonstrate graphene dispersions with concentrations up to approximately 0.01 mg ml(-1), produced by dispersion and exfoliation of graphite in organic solvents such as N-methyl-pyrrolidone. This is possible because the energy required to exfoliate graphene is balanced by the solvent-graphene interaction for solvents whose surface energies match that of graphene. We confirm the presence of individual graphene sheets by Raman spectroscopy, transmission electron microscopy and electron diffraction. Our method results in a monolayer yield of approximately 1 wt%, which could potentially be improved to 7-12 wt% with further processing. The absence of defects or oxides is confirmed by X-ray photoelectron, infrared and Raman spectroscopies. We are able to produce semi-transparent conducting films and conducting composites. Solution processing of graphene opens up a range of potential large-area applications, from device and sensor fabrication to liquid-phase chemistry.
authors.affiliation: School of Physics, Trinity College Dublin, Dublin 2, Ireland.
authors.forename: Yenny
authors.initials: Y
authors.lastname: Hernandez
authors.forename: Valeria
authors.initials: V
authors.lastname: Nicolosi
authors.forename: Mustafa
authors.initials: M
authors.lastname: Lotya
authors.forename: Fiona M
authors.initials: FM
authors.lastname: Blighe
authors.forename: Zhenyu
authors.initials: Z
authors.lastname: Sun
authors.forename: Sukanta
authors.initials: S
authors.lastname: De
authors.forename: I T
authors.initials: IT
authors.lastname: McGovern
authors.forename: Brendan
authors.initials: B
authors.lastname: Holland
authors.forename: Michele
authors.initials: M
authors.lastname: Byrne
authors.forename: Yurii K
authors.initials: YK
authors.lastname: Gun'Ko
authors.forename: John J
authors.initials: JJ
authors.lastname: Boland
authors.forename: Peter
authors.initials: P
authors.lastname: Niraj
authors.forename: Georg
authors.initials: G
authors.lastname: Duesberg
authors.forename: Satheesh
authors.initials: S
authors.lastname: Krishnamurthy
authors.forename: Robbie
authors.initials: R
authors.lastname: Goodhue
authors.forename: John
authors.initials: J
authors.lastname: Hutchison
authors.forename: Vittorio
authors.initials: V
authors.lastname: Scardaci
authors.forename: Andrea C
authors.initials: AC
authors.lastname: Ferrari
authors.forename: Jonathan N
authors.initials: JN
authors.lastname: Coleman
mesh_terms: D006108:Graphite / Q000138:chemical synthesis* / Q000737:chemistry; D044367:Phase Transition; D011760:Pyrrolidinones / Q000737:chemistry; D013057:Spectrum Analysis / Q000379:methods
chemical_list: D011760:Pyrrolidinones; D006108:Graphite; C038678:N-methylpyrrolidone