Synthesis and Characterization of Nano-MnO[sub 2] for Electrochemical Supercapacitor Studies

Abstract

Nanostructured was synthesized at ambient condition by reduction of potassium permanganate with aniline. Powder X-ray diffraction, thermal analysis (thermogravimetric and differential thermal analysis), Brunauer–Emmett–Teller surface area, and infrared spectroscopy studies were carried out for physical and chemical characterization. The as-prepared was amorphous and contained particles of diameter. Upon annealing at temperatures , the amorphous attained crystalline α-phase with a concomitant change in morphology. A gradual conversion of nanoparticles to nanorods is evident from scanning electron microscopy and transmission electron microscopy (TEM) studies. High-resolution TEM images suggested that nanoparticles and nanorods grow in different crystallographic planes. Capacitance behavior was studied by cyclic voltammetry and galvanostatic charge–discharge cycling in a potential range from vs SCE in sodium sulfate solution. Specific capacitance of about was obtained at a current density of .