Synthesis of manganese oxide for supercapacitors: Effect of precursor on electrocatalytic performance

Manganese oxides with various phases were prepared by a double solvent precipitation method using manganese chloride (MnCl₂), manganese sulfate (MnSO₄), and manganese acetate (Mn(Ac)₂) as precursors in 2-propanol. The physicochemical properties of as-prepared catalysts were characterized by scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray diffraction (XRD), and Brunauer-Emmett-Teller (BET) analysis. -Phase MnO₂ (with a needle-like shape), -phase MnO₂ (with a globular shape), and -phase Mn₃O₄ (with a mixed shape) were successfully synthesized using MnCl₂, MnSO₄, and Mn(Ac)₂, respectively. In order to investigate the electrochemical properties of the synthesized manganese oxides, cyclic voltammetry (CV) was conducted in a standard three-electrode system in 1 M sodium sulfate (Na₂SO₄) solution at a scan rate of 80 mV/s. The electrochemical performance of the samples was strongly influencedby the precursors. The electrode synthesized with the MnSO₄ exhibited the highest catalytic activity and stability, which were attributed to the high surface area and well-developed morphology.