Ultrathin MnO2 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 MnO2 nanorods (3 nm in diameter) on surfaces of almost all major classes of electronic conducting polymer nanofibers merely using conducting polymer nanofibers and KMnO4 as raw materials. The loading amount and patterning of MnO2 nanorods on surfaces of conducting polymers of typical polyaniline (PANI) nanofibers can be controlled by simply altering the KMnO4 concentration. Mechanisms involved in the formation of PANI-MnO2 composites were further revealed according to experimental results. In comparison with PANI nanofibers, the specific capacitance of PANI-MnO2 composites has substantially increased by almost fourfold, with values as high as 417 F g(-1) achieved. The combination of ultrathin MnO2 nanorods and PANI nanofibers into one-dimensional hierarchical nanostructures show excellent electrochemical properties for energy storage applications, which evidence their potential application as supercapacitors.