In-situ reduction of graphene oxide for electrochemical supercapacitor application

Reduced graphene oxide (rGO) is a widely studied electrode material for energy storage, however, its strong re-stacking tendency during chemical reduction always leads to a degraded specific surface area and thus limits its performance. Therefore, it is necessary to control the morphology of rGO during the reduction process. Here, we develop a novel in-situ membrane-based method for the reduction of graphene oxide (GO) using a green and efficient vitamin C (VC) aqueous solution as reductant. The obtained electrode material (vitamin C reduced GO via membrane-based method, VG-M) exhibits a specific capacitance of 174 F/g at 1 A/g and 75.9% of retention at 40 A/g, which is about 9 times better than the highly self-stacked material from conventional methods (vitamin C reduced GO via stirring method, VG-S). This designed method successfully achieves the maintenance of rGO sheet morphology through laminar confinement in GO membrane and presents a simple approach towards two-dimensional (2D) material morphology control.