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Proton Conductivities of Graphene Oxide Nanosheets: Single, Multilayer, and Modified Nanosheets
Author(s) -
Hatakeyama Kazuto,
Karim Mohammad Razaul,
Ogata Chikako,
Tateishi Hikaru,
Funatsu Asami,
Taniguchi Takaaki,
Koinuma Michio,
Hayami Shinya,
Matsumoto Yasumichi
Publication year - 2014
Publication title -
angewandte chemie
Language(s) - English
Resource type - Journals
eISSN - 1521-3757
pISSN - 0044-8249
DOI - 10.1002/ange.201309931
Subject(s) - graphene , conductivity , oxide , materials science , proton , electrolyte , thermal conduction , ethylenediamine , relative humidity , epoxy , drop (telecommunication) , chemical engineering , proton transport , analytical chemistry (journal) , composite material , nanotechnology , electrode , inorganic chemistry , chemistry , organic chemistry , thermodynamics , telecommunications , physics , quantum mechanics , computer science , engineering , metallurgy
Proton conductivities of layered solid electrolytes can be improved by minimizing strain along the conduction path. It is shown that the conductivities ( σ ) of multilayer graphene oxide (GO) films (assembled by the drop‐cast method) are larger than those of single‐layer GO (prepared by either the drop‐cast or the Langmuir‐Blodgett (LB) method). At 60 % relative humidity (RH), the σ value increases from 1×10 −6 S cm −1 in single‐layer GO to 1×10 −4 and 4×10 −4 S cm −1 for 60 and 200 nm thick multilayer films, respectively. A sudden decrease in conductivity was observed for with ethylenediamine (EDA) modified GO (enGO), which is due to the blocking of epoxy groups. This experiment confirmed that the epoxide groups are the major contributor to the efficient proton transport. Because of a gradual improvement of the conduction path and an increase in the water content, σ values increase with the thickness of the multilayer films. The reported methods might be applicable to the optimization of the proton conductivity in other layered solid electrolytes.