3D graphene/ZnO nanorods composite networks as supercapacitor electrodes

•3DG/ZnO nanorods composites were prepared by CVD and hydrothermal method.•Integration of 3DG and ZnO nanorods exhibited enhanced specific capacitance as supercapacitor.•We evaluated the dependence of specific capacitance on ZnO growth time.•We obtained specific capacitance of 554.23 F/g at 5 mV/s.•The specific capacitance decreased to 94.4% after 2300 cycles.