International Journal of Hydrogen Energy, Vol.43, No.33, 16136-16140, 2018
Optimum interlayer distance for hydrogen storage in pillared-graphene oxide determined by H-2 pressure-dependent electrical conductance
To establish the relation between optimum interlayer distance for hydrogen storage and electrical conductance, we measured the electrical conductance (G) of 3-dimensional graphene oxide (GOA) depending on high H-2 pressure, from vacuum to 20 bar. The GOA was synthesized using diaminoalkanes with two lengths of alkyl chains, and the interlayer distance of GOA was modulated by thermal annealing. A decrease in G was observed as the H-2 pressure increased. The maximum variation in G was observed at 7.0 angstrom of interlayer distance. When the interlayer distance-dependent H-2 uptake was considered, we confirmed that the maximum variation in G as well as optimum H-2 uptake occurred at the same interlayer distance, 7.0 angstrom. The variation in G due to H-2 exposure provides understanding about the behavior of hydrogen molecules on these materials and on the modulation of the electronic structure of the materials. (C) 2018 Hydrogen Energy Publications LLC. Published by Elsevier Ltd. All rights reserved.
Keywords:Graphene oxide;3-dimensional structure;Hydrogen storage;Optimum interlayer distance;Electrical conductance