Energy-saving and environmentally friendly electrodeposition of γ-MnO2

Abstract

The paper reports a new energy-saving and environmentally friendly method for synthesis of γ-MnO₂ using a Pt/C gas diffusion electrode instead of the traditional cathode. The Pt/C gas diffusion electrode has high activity in a 120 g dm⁻³ MnSO₄·H₂O + 30 g dm⁻³ H₂SO₄ electrolyte at 80 °C. At the same time, the cell voltage and electrode potential of the electrolytic cell with the Pt/C gas diffusion electrode as cathode are measured at 100 A m⁻² for 12 h. The results show that the Pt/C gas diffusion electrode demonstrated good stability. The effects of the current density on the synthesis of γ-MnO₂ (EMD) is studied, and the results show that the electric energy consumption of the GDE as cathode drops 61.06–57.75%, 65.6–62.9% and 61.4–55% compared with that of the Cu, Graphite, and Pt cathode at 80 A m⁻², 100 A m⁻², and 120 A m⁻² respectively in 12 hours. The γ-MnO₂ (EMD) shows a better discharge performance as a cathode material of Zn–MnO₂ than the commercial battery grade manganese dioxide.