Controllable synthesis of porous CuO-Cu2O/rGO microspheres composite as high-performance electrode material for supercapacitors

Porous copper oxides/reduced graphene oxide (CuO-Cu2O/rGO) microspheres composite was first prepared by a simple and environmentally friendly one-step hydrothermal method. The influences of graphene oxide (GO) on the ratio of CuO and Cu2O and the corresponding electrochemical performance of the composite were investigated systematically. It was found that when the ratio of CuO and Cu2O is about 1:5 by controlling GO adding amount, the composite exhibits excellent electrochemical performance, such as high specific capacitance (470 F·g−1 at a current density of 1 A·g−1), excellent rate capability (85.9% of capacity retention as current density increases from 1 to 10 A·g−1) and long cycle stability (81.3% of capacity retention after 5000 cycles at a current density of 1 A·g−1). Therefore, the porous high-performance CuO–Cu2O/rGO microspheres composite has a great potential for supercapacitor applications.