Growth and characterization of carbon-supported MnO2 nanorods for supercapacitor electrode

Preparation of carbon-supported nano-MnO2 composite (MnO2/C) by microemulsion process is reported. As evidenced by high-resolution transmission electron microscopy (HR-TEM) micrographs, highly dispersed MnO2 nanorods over carbon surface with clear inter-phase boundaries are obtained. X-ray diffraction results of as grown composite powder confirm the αMnO2 phase of manganese oxide that on annealing at elevated temperatures undergo oxidative transformation to Mn3O4 and Mn2O3 phases. The small size and high dispersion of MnO2 nanorods in the composite material exhibited high capacitance of 165 Fg−1 for MnO2/C and 458 Fg−1 for pure MnO2.