Significant improvement in the electrochemical performances of nano-nest like amorphous MnO2 electrodes due to Fe doping

Amorphous and highly porous nanonest like Fe:MnO2 thin films have been potentiostatically synthesized and are characterized by using X-ray diffraction (XRD), Field emission scanning electron microscopy (FESEM), Energy dispersive X-ray analysis (EDAX), Fourier transform infrared spectroscopy (FTIR), wettability test and optical properties. The supercapacitive performance of Fe:MnO2 electrodes were tested using cyclic voltammetry (CV), charge–discharge and impedance techniques in 1 M Na2SO4 electrolyte. The effect of Fe doping on structural, morphological, compositional and supercapacitive properties of MnO2 thin films has been investigated. Further, the effect of electrolyte concentration and scan rate on the supercapacitance of MnO2 and Fe:MnO2 electrodes have been studied. The results showed that as Fe doping concentration increases up to 2 at% the supercapacitance increases from 166 to 231 F g−1. The maximum specific capacitance of 273 F g−1 was achieved for 2 at% Fe:MnO2 at 5 mV s−1 scan rate.