Rose rock-shaped nano Cu₂O anchored graphene for high-performance supercapacitors via solvothermal route

Novel rose rock-shaped cuprous oxide anchored graphene nanocomposite (Cu₂O-GN) is successfully synthesized by a simple and efficient one-step solvothermal method. Notably, the reduction of graphene oxide (GO) and deposition of nano-Cu₂O on GN occur simultaneously during the polyol reaction process. The nanocomposite is systematically characterized by X-ray diffraction (XRD), transmission electron microscopy (TEM), scanning electron microscopy (SEM) and X-ray photoelectron spectroscopy (XPS). We also explore the formation mechanism of Cu₂O-GN including the concentration effect of the precursor, precipitation agent, GO, and heating rate on the morphology of the resulting nanocomposite. It is noteworthy that Cu₂O is gradually decorated on the large sheets of GN to form ordered three-dimensional nanostructure with the optimized concentration of GO, which is crucial to the growth of the final nanoarchitectures. In addition, the electrochemical properties of the Cu₂O-GN nanocomposite are investigated by cyclic voltammetry and galvanostatic charge-discharge measurements. The composite shows a favorable electrochemical capacitance (416 F g^-1 at 1 A g^-1), rate performance and cycling stability. Also, a high specific capacitance and good retention point to its promising applications as electrode materials in supercapacitors.