Alcohol-dependent environments for fabricating graphene aerogels toward supercapacitors

Highly porous graphene aerogels with excellent flexibility were fabricated via simultaneous reduction and assembly of graphene oxides in various alcohols. Ethanol, isopropanol, and ethylene glycol of different steric environments for the alcohol groups were found to dominantly determine the porous structures, surface areas and chemical compositions. The observed different reduction degrees of the alcohols lead to different charge transfer ability and electrochemical capacitance. On the basis of physical and electrochemical properties, the mechanisms associated with the alcohol species have been discussed. Furthermore, the resultant supercapacitors assembled by the graphene aerogels exhibited effective specific capacitance up to 287 F g^-1 (at current density of 0.1 A g^-1) with excellent cycle stability (>91% capacitance retention upon 8000 cycles). Combination of the alcohol-dependent energy storage performance and related mechanisms promises great potential for engineering and fabricating advanced graphene-based porous nanostructures of broad applications.