Synthesis of Mn₃O₄ nanoparticles via chemical precipitation approach for supercapacitor application

Highlights: • Facile synthesis of Mn₃O₄ nanoparticles at room temperature via simple chemical precipitation method. • Fabricated supercapacitor device shows maximum specific capacitance in 1 M Na₂SO₄. • 77% of specific capacitance is retained even after 1000 cycles. - Abstract: A simple chemical precipitation method has been used for the preparation of Mn₃O₄ nanoparticles at room temperature. The crystal structure and morphology studies of the resulting Mn₃O₄ nanoparticles were characterized by powder X-ray diffraction (XRD), Fourier transform-infrared spectroscopy (FT-IR), Raman spectroscopy, scanning electron microscope (SEM), transmission electron microscope (TEM), N₂ adsorption and desorption and X-ray photoelectron spectroscopy (XPS). The electrochemical properties of the Mn₃O₄ nanoparticles were then investigated using cyclic voltammetry (CV), galvanostatic charge–discharge and electrochemical impedance spectroscopy (EIS) analysis. The supercapacitive properties of Mn₃O₄ nanoparticles in the presence of 1 M Na₂SO₄ exhibited a high specific capacitance of 322 F g⁻¹ at a current density of 0.5 mA cm⁻² in the potential range from −0.1 to +0.9 V and about 77% of the initial capacitance was retained after 1000 cycles, indicating that the Mn₃O₄ electrode owns a good electrochemical stability and capacitance retention capability. The results suggest that the obtained Mn₃O₄ nanoparticles is a promising electrode material for supercapacitor applications