Electrodeposition of Manganese Oxide Nanosheets as Supercapacitor Electrode Materials

Abstract

Manganese oxide (MnOx) thin films were prepared on stainless steel (SS) 304 by galvanostatic (GS) mode of electrodeposition technique using different precursors; 0.1 M potassium permanganate (KMnO4) and 0.1 M manganese sulfate (MnSO4) solutions. The electrodeposition condition was set at a constant current of 1 mA/cm2. Different precursors provide MnOx thin films with different morphologies. Using KMnO4 as a precursor, the MnOx thin film was deposited (MnOx-K), while using MnSO4 as a precursor, the MnOx nanosheets with a thickness of approximately 40 nm were formed (MnOx-S). XPS results evidence the formation of manganese oxide with different oxidation states composition by different precursors. Electrochemical measurements were carried out in a three-electrode setup using Pt and Ag/AgCl electrodes as counting and reference electrodes, respectively and 1M Na2SO4 aqueous solution as electrolyte. MnOx-K at a deposition time of 10 min shows the highest specific capacitance of 233.55±19.01 F/g. The specific capacitance improvement of MnOx-K may be attributed to MnOx nanosheet structure which increases surface area of electrode.