Synthesis of Ni/graphene nanosheets via electron beam irradiation and their enhanced electrochemical hydrogen storage properties

A nanostructured Ni(OH)₂/graphene oxide (GO) hybrid was fabricated via the controlled reassembly of exfoliated GO with nickel hydroxide to form a delaminated structure. To examine the effect of electron beam irradiation on the hybrid material, the obtained Ni(OH)₂/GO was exposed to the electron beam, and the total doses of the electron beam were varied from 150 to 250 kGy. The electron-beam-irradiated hybrid was reduced to fabricate a new nanostructured material in which nickel nanoparticles were homogeneously deposited onto the graphene nanosheets (GNS). According to the transmission electron microscopy analysis, a large number of defect sites could be developed after the electron beam treatments. The electrochemical hydrogen storage property (approximately 170 mAh/g) of the hybrid sample after the electron beam treatment was determined to be much superior to that of the GNS (approximately 20 mAh/g), demonstrating that this synthetic methodology via electron beam bombardment could be extended to the development of new nanostructured materials with enhanced hydrogen storage properties.