Investigation of structural electron density distribution and enhanced electrochemical properties of spinel structured MnCo2O4/polyaniline nanocomposite prepared by facile and economical method

Abstract

Abstract: A nanocomposite of AB2O4 structured binary metal oxide and conducting polymer was synthesized by cost effective procedure. The procedure for synthesis of chosen MnCo2O4 was solution combustion method and the composite MnCo2O4/polyaniline was obtained by physical blending. The procedure involved was very simple, speedy and inexpensive. The derived results from Scherrer and size strain plot methods showed good concurrence. The Strain value of the composite from Scherrer was 0.3406 and from SSP was 0.3332. Lattice parameter revealed in Rietveld method also matched well with Scherrer. The observations of functional groups through FT-IR confirmed the purity of the samples and presence of polyaniline and metal oxide. The morphological changes examined through High Resolution Scanning Electron Microscopy, favored enhanced conductivity in the composite showed that the changes occurred have facilitated more conductivity in the MnCo2O4/polyaniline composite. The size of the nanoparticle revealed by High Resolution Transmission Electron Microscopy (HR-TEM) was 8–50 nm, showing good concurrence with the size observed in XRD which was 10–65 nm and shape in SEM. Selected Area Electron Diffraction patterns were also in confirmation of crystallinity of the samples and planes revealed by XRD. The variations in bond length and electron density distribution investigated by MEM technique, a unique report in this work also assured the improved energy storage potential of the nanocomposite material. The electro chemical analyses viz., cyclic voltammetry, chronopotentiometry and Electrochemical Impedance Spectroscopy by a three electrode assemblage with 6 M KOH as electrolyte have supported the above findings by confirming higher specific capacitance and low resistance. In the nanocomposite material synthesized. The maximum specific capacitance of the MnCo2O4/polyaniline nanocomposite was 875 F/g and, the pure MnCo2O4 was 713 F/g at the scan rate 5 mV/S. The ESR value for pure was 4.07 Ω and that of the composite electrode was 2.75 Ω. Graphic abstract: [Figure not available: see fulltext.]