Hydrothermal synthesis and electrochemical properties of MnO₂ nanostructures

Manganese oxide (MnO 2 ) nanowires with diameters of 40–50 nm and lengths up to several micrometers have been successfully synthesized through a simply hydrothermal route. The influences of synthetic parameters, such as reaction time, and reaction temperature, on the growth and morphologies of MnO 2 nanowires have been investigated. It is found that MnO 2 nanowires can be evolved into MnO 2 microrods with the reaction time/temperature increased. The electrochemical characterization of MnO 2 nanostructures was carried out in 1 M Na 2 SO 4 aqueous electrolyte at the scan rate of 10 mV s ‐1 . The results indicate that the MnO 2 microrods obtained when the reaction performed at 200 °C for 24 h showed the best performance for supercapacitor. (© 2009 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)