Preparation of Mn3O4 microspheres via glow discharge electrolysis plasma as a high-capacitance supercapacitor electrode material

Manganic manganous oxide (Mn3O4) microspheres were prepared at 550 V discharge voltage in 2 g L−1 NaNO3 solution by one-step method via cathode glow discharge electrolysis (CGDE) plasma technique for high-capacitance supercapacitor electrode materials, in which Mn foil and Pt needle point were served as anode and cathode, respectively. The structure, phase composition and morphology of as-prepared products were characterized by FT-IR, XRD, XPS, SEM, TEM and BET analysis. A mechanism for the fabrication of Mn3O4 microspheres was proposed. The electrochemical behaviors of the Mn3O4 microspheres were examined in 1.0 mol L−1 Na2SO4 electrolyte. The results showed that Mn3O4 microspheres are composed of small nanospheres with sizes of about 20 nm and large nanospheres with sizes of about 177 nm. Specific surface area of microspheres is 48.03 m2 g−1. The Mn3O4 microsphere as an electrode has an outstanding specific capacitance of 360 F g−1 at 0.5 A g−1 and a superior cycling property of 83.6 % capacity retention after 1000 cycles at 1 A g−1, evidencing the potential as an electrode material for supercapacitor.