Synthesis of γ-MnOOH and β-MnO2 nanowires and their electrochemical capacitive behavior

Abstract

In the present work γ-MnOOH nanowires have been synthesized employing hydrothermal oxidation of MnSO4 in the presence of (NH 4)2S2O8 in aqueous LiOH solution. The synthesized γ-MnOOH nanowires were transformed into β-MnO 2 nanowires by their subsequent calcinations at 300°C. X-ray diffraction (XRD), Fourier transform infrared (FTIR) analysis and Field emission scanning electron microscope (FE-SEM) have confirmed that both γ-MnOOH and β-MnO2 nanowires are single crystal of having 20 to 30 nm diameter and > 5 μm in length. The prepared β-MnO2 nanowires have shown their better electrochemical capacitive behavior as compared to capacitance reported for commercial grade MnO2 particles.