Electrochemical hydrogen storage of the graphene sheets prepared by DC arc-discharge method

Graphene, as the fundamental two-dimensional carbon structure with exceptionally high crystal and electronic quality, had attracted increasing interest for its promising potential applications. In this article, the few-layer graphene sheets have been achieved by the direct current (DC) arc-discharge under hydrogen atmosphere, using pure graphite rods as the electrodes. The influence of hydrogen pressures (e.g. 0.03 MPa, 0.05 MPa, 0.07 MPa) on the products and their electrochemical properties for hydrogen storage were investigated. It is indicated that the graphene sheets were less than 10 layers and with the sizes in range of 200-500 nm. Among all graphene sheet samples, the highest capacity for electrochemical hydrogen storage was 147.8 mAh/g. Mechanism for electrochemical hydrogen insertion/desertion of such graphene sheet was discussed with respect to the single-layer graphene and multi-layer graphite. (C) 2012 Elsevier B.V. All rights reserved.