The impact of post-synthesis processing in, for example, graphene oxid or reduced graphene oxide materials for supercapacitor electrodes has been analyzed. A comparative study of vacuum, freeze and critical point drying was carried out for graphene oxide or hydrothermally reduced graphene oxide demonstrating that the optimization of the specific surface area and preservation of the porous network is important to maximize its properties such as supercapacitance performance. As described below, using a supercritical fluid as the drying medium, unprecedented values of specific surface area (e.g., 364 m2 g−1) and supercapacitance (e.g., 441 F g−1) for this class of materials were achieved.