A facile one-pot hydrothermal synthesis of branched α-MnO2 nanorods for supercapacitor application

Abstract

Branched α-MnO₂ nanorods are synthesized using a facile hydrothermal method without surfactants or templates. The formation of α-MnO₂ with different morphologies, including branched nanorods and nanorods with controllable length, is achieved by controlling the starting concentration of reactants. The morphology and structure of the branched α-MnO₂ nanorods are fully characterized and the growth mechanism is proposed based on the experimental observation. The novel structures presented here enrich the nanoscale community of α-MnO₂ materials, thus enabling greater potential applications. The electrochemical properties of as-synthesized branched α-MnO₂ nanorods are also studied by cyclic voltammetry (CV) and galvanostatic charge/discharge measurement. The branched α-MnO₂ nanorod electrode shows a high specific capacitance of 182 F g⁻¹ at a current density of 2 A g⁻¹, with a good rate capability (72.5% at 64 A g⁻¹) and excellent cycling stability.