Sonochemically synthesized MnO2 nanoparticles as electrode material for supercapacitors

In this study, manganese oxide (MnO2) nanoparticles were synthesized by sonochemical reduction of KMnO4 using polyethylene glycol (PEG) as a reducing agent as well as structure directing agent under room temperature in short duration of time and characterized by powder X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR), Scanning electron microscope (SEM), Transmission electron microscopy (TEM) and Brunauer–Emmett–Teller (BET) analysis. A supercapacitor device constructed using the ultrasonically-synthesized MnO2 nanoparticles showed maximum specific capacitance (SC) of 282 Fg−1 in the presence of 1 M Ca(NO3)2 as an electrolyte at a current density of 0.5 mA cm−2 in the potential range from 0.0 to 1.0 V and about 78% of specific capacitance was retained even after 1000 cycles indicating its high electrochemical stability.