▎ 摘　　要

Improving the electrochemical properties of graphene aerogels (GAs) without doping or making composites is an attractive synthetic strategy. In this work we report some effects of graphene sheet dimensions on the properties of GAs. Nanographene aerogels (nG-AGs) were synthesized using nanographene oxide (nGO) powder with a mean platelet diameter of 90nm. In-situ Fourier tranformation infrared (FTIR) spectroscopy during gelation revealed a longer fast-gelation regime for nG-AGs than for standard graphene aerogels (stdG-AGs). The surface-area-normalized capacitance of nG-AGs calculated from cyclic voltammetry is 16% higher than that of stdG-AGs, and the onset of hydrogen evolution is observed at a lower over-potential. These observations can be attributed to an increased density of edge sites and defects in nanographene sheets. Our results indicate that the diameter of the precursor graphene sheets can be used as a parameter to optimize the electrochemical properties of GAs depending on the application.