We have demonstrated a one-step and effective electrochemical method to synthesize graphene/MnO2 nanowall
hybrids (GMHs). Graphene oxide (GO) was electrochemically reduced to graphene (GN), accompanied by the
simultaneous formation of MnO2 with a nanowall morphology via cathodic electrochemical deposition. The
morphology and structure of the GMHs were systematically characterized by scanning electron microscope
(SEM), X-ray photoelectron spectroscopy (XPS), X-ray diffraction (XRD), and Raman spectroscopy. The resulting
GMHs combine the advantages of GN and the nanowall array morphology of MnO2 in providing a conductive
network of amorphous nanocomposite, which shows good electrochemical capacitive behavior. This simple
approach should find practical applications in the large-scale production of GMHs.