title: Graphene oxide nanosheet with high proton conductivity.
abstract: We measured the proton conductivity of bulk graphite oxide (GO'), a graphene oxide/proton hybrid (GO-H), and a graphene oxide (GO) nanosheet for the first time. GO is a well-known electronic insulator, but for proton conduction we observed the reverse trend, as it exhibited superionic conductivity. The hydrophilic sites present in GO as -O-, -OH, and -COOH functional groups attract the protons, which propagate through hydrogen-bonding networks along the adsorbed water film. The proton conductivities of GO' and GO-H at 100% humidity were ∼10(-4) and ∼10(-5) S cm(-1), respectively, whereas that for GO was amazingly high, nearly 10(-2) S cm(-1). This finding indicates the possibility of GO-based perfect two-dimensional proton-conductive materials for applications in fuel cells, sensors, and so on.
authors.affiliation: Graduate School of Science and Technology, Kumamoto University , 2-39-1 Kurokami, Kumamoto 860-8555, Japan.
authors.forename: Mohammad Razaul
authors.initials: MR
authors.lastname: Karim
authors.forename: Kazuto
authors.initials: K
authors.lastname: Hatakeyama
authors.forename: Takeshi
authors.initials: T
authors.lastname: Matsui
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Takehira
authors.forename: Takaaki
authors.initials: T
authors.lastname: Taniguchi
authors.forename: Michio
authors.initials: M
authors.lastname: Koinuma
authors.forename: Yasumichi
authors.initials: Y
authors.lastname: Matsumoto
authors.forename: Tomoyuki
authors.initials: T
authors.lastname: Akutagawa
authors.forename: Takayoshi
authors.initials: T
authors.lastname: Nakamura
authors.forename: Shin-ichiro
authors.initials: S
authors.lastname: Noro
authors.forename: Teppei
authors.initials: T
authors.lastname: Yamada
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Kitagawa
authors.forename: Shinya
authors.initials: S
authors.lastname: Hayami