Abstract:
We report the use of a spray pyrolysismethod to synthesize high surface area (BET surface area of 139m2 g 1)
self-organized, micron sized urchin-like composites made up of reduced graphene oxide and needle-shaped
manganese oxide (rGO–Mn2O3–Mn3O4). Maximum capacitances of 425 Fg 1 at 5 mV s 1 from a three
electrode set up and 133 Fg 1 at a current density of 0.2 Ag 1 were recorded using an asymmetric two
electrode set up with graphene as the anode. The composite material also showed a capacitance retention
of 83% over 1000 cycles. We attribute this remarkable performance to the high specific surface area due to
the urchin-like hollow structures and synergy between the manganese oxide and reduced graphene oxide
materials within the composite. Furthermore, this synthesis technique can be exploited further in the bulk
synthesis of cost effective graphene–metal oxide hybrid materials for energy storage applications.
