One-step hydrothermal synthesis of hierarchical MnO2-coated CuO flower-like nanostructures with enhanced electrochemical properties for supercapacitor

We developed a one-step hydrothermal approach to fabricate hierarchical MnO2 nanosheets on flowerlike CuO nanostructures without any surfactant. With this method, the ultrathin MnO2 nanosheets conformably and uniformly grew around every nanopetal of flower-like CuO. Furthermore, the electrochemical properties of the MnO2/CuO nanocomposite electrodes were elucidated by cyclic voltammograms, galvanostatic charge/discharge tests and electrochemical impedance spectroscopy in 1 M Na2SO4 electrolyte. The electrochemical results demonstrated that this unique MnO2/CuO nanostructure exhibited a specific capacitance of 167.2 F g(-1) and excellent cycling stability (88.6% retention after 5000 cycles). Indeed, these remarkable findings will enable low-cost MnO2/CuO nanocomposite attractive for high-performance supercapacitors. (C) 2013 Elsevier B.V. All rights reserved.