Hydrothermal synthesis and electrochemical properties of MnO2 nanostructures

Manganese oxide (MnO₂) 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 MnO₂ nanowires have been investigated. It is found that MnO₂ nanowires can be evolved into MnO₂ microrods with the reaction time/temperature increased. The electrochemical characterization of MnO₂ nanostructures was carried out in 1 M Na₂SO₄ aqueous electrolyte at the scan rate of 10 mV s^‐1. The results indicate that the MnO₂ 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)