Facile Synthesis of Novel Nanostructured MnO2 Thin Films and Their Application in Supercapacitors

Nanostructured alpha-MnO2 thin films with different morphologies are grown on the platinum substrates by a facile solution method without any assistance of template or surfactant. Microstructural characterization reveals that morphology evolution from dandelion-like spheres to nanoflakes of the as-grown MnO2 is controlled by synthesis temperature. The capacitive behavior of the MnO2 thin films with different morphologies are studied by cyclic voltammetry. The alpha-MnO2 thin films composed of dandelion-like spheres exhibit high specific capacitance, good rate capability, and excellent long-term cycling stability.