Optimum interlayer distance for hydrogen storage in pillared-graphene oxide determined by H2 pressure-dependent electrical conductance

Abstract 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 A 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 A. 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.