Controllable Hydrothermal Synthesis of MnO2 Nanostructures

摘要

Various MnO2 nanostructures with controlling phases and morphologies, like α-MnO2 nanorods, nanotubes, nanocubes, nanowires and β-MnO2 cylinder/spindle-like nanosticks have been successfully prepared by hydrothermal method, which is simply tuned by changing the ratio of Mn precursor solution to HCl, Mn(Ac)2·4H2O or C6H12O6·H2O, surfactants and reaction temperature and time. The study found out that temperature is a crucial key to get a uniform and surface-smooth nanorod. High ratio of KMnO4 to HCl leads to well dispersed MnO2 nanorods and changing the precursor of HCl into Mn(Ac)2·4H2O or C6H12O6·H2O results in forming nanowires or nanocubes. Different shapes such as cylinder/spindle-like nanosticks could be obtained by adding surfactants. Since the properties rely on the structure of materials firmly, these MnO2 products would be potentially used in supercapacitor and other energy storage applications.