Hierarchically structured TiO2@MnO2 nanowall arrays as potential electrode material for high-performance supercapacitors

We have reported a facile route for the fabrication of TiO2@MnO2 core–shell nanostructures for use as an electrode material, using a simple hydrothermal process for supercapacitor applications. Field-emission scanning electron microscopy and transmission electron microscopy studies confirmed the formation of a MnO2 nanowall shell structure on the core of TiO2 nanorod surfaces. The nanostructured TiO2@MnO2 core–shell was used as an electrode material, which exhibited excellent electrochemical properties with an improved areal capacitance of 22.19 mF cm−2 (TM-3) at a scan rate of 5 mV s−1 in a 1-M Na2SO4 electrolyte solution. Moreover, the electrode material demonstrated excellent performance with long term cycling stability, by retaining 85% of its initial capacitance after 4000 cycles.