Large-Scale Synthesis of Metal-Ion-Doped Manganese Dioxide for Enhanced Electrochemical Performance

Abstract

One-dimensional (1D) MnO2 was widely applied in areas of enzyme biosensor, industrial sieves and energy storage materials owing to its excellent thermal, optical, magnetic and chemical features. However, its practical application into energy storage devices is often hindered by the bad electronic conductivity (10-5~10-6 S cm-1). As widely known, doping with hetero elements is an efficient way to enhance the electronic conductivity of metal oxides. Herein, a novel and simple molten salt method is developed in order to achieve a large-scale preparation of 1D MnO2 nanowires. Such approach also realizes the easy tuning of electrical properties through doping with different transition metal ions. Based on first principle calculation as well as four-probe measurement, the conductivity of the doped MnO2 nanowires can be promoted efficiently by utilizing such protocol. Meanwhile, a possible doping route is discussed in detail. As a result, a superior electrochemical performance can be observed in such metal ions (M+) doped nanowires. Such high-quality M+ doped MnO2 nanowires can satisfy a broad range of application needs beyond the electrochemical capacitors.