Ultrathin MnO 2 Nanorods on Conducting Polymer Nanofibers as a New Class of Hierarchical Nanostructures for High-Performance Supercapacitors

A facile and scalable one-step strategy has been proposed for patterning ultrathin MnO 2 nanorods (3 nm in diameter) on surfaces of almost all major classes of electronic conducting polymer nanofibers merely using conducting polymer nanofibers and KMnO 4 as raw materials. The loading amount and patterning of MnO 2 nanorods on surfaces of conducting polymers of typical polyaniline (PANI) nanofibers can be controlled by simply altering the KMnO 4 concentration. Mechanisms involved in the formation of PANI–MnO 2 composites were further revealed according to experimental results. In comparison with PANI nanofibers, the specific capacitance of PANI–MnO 2 composites has substantially increased by almost fourfold, with values as high as 417 F g –1 achieved. The combination of ultrathin MnO 2 nanorods and PANI nanofibers into one-dimensional hierarchical nanostructures show excellent electrochemical properties for energy storage applications, which evidence their potential application as supercapacitors.