▎ 摘　　要

This study investigated the effect of structural changes of thermally exfoliated graphene oxide on its hydrogen uptake property. Exfoliation temperature was observed to have a significant effect on the surface and structural properties of the samples. The graphene oxide (GO) was exfoliated at different temperatures between 200 and 500 degrees C in hydrogen flow. Reduction in the oxygen content was observed on increasing the exfoliation temperature. Exfoliated GO samples had a fluffy layered structure. The separation between the graphene layers increased with increasing exfoliation temperature. The GO exfoliated at 300 degrees C showed the highest surface area of 248 m(2)/g. The same sample also had the highest total pore volume (1.64 cm(3)/g). The lowest exfoliation temperature of 200 degrees C was least effective for separations of layers. Consequently, the surface area, as well as pore volume, was lowest for the sample. Again at higher exfoliation temperature of 500 degrees C, the partial damage to layers may have been responsible for lowering of both the values. The hydrogen uptake of 3.12 wt%, obtained for GO exfoliated at 300 degrees C, was the maximum value observed in this study. It was measured at -196 degrees C and 30 bar. This uptake is much higher compared to that reported for exfoliated GO samples having similar surface areas. The considerable hydrogen uptake of the present sample may be the combined effect of high pore volume, mesoporous structure, fluffy layered nature and significant content of surface oxygen heteroatom.