Electrochemical performance and charge density distribution analysis of Ag/NiO nanocomposite synthesized from Withania somnifera leaf extract

Abstract

• Ag/NiO nanocomposite is successfully synthesized using leaf extract of Withania somnifera viasol-gel method. • The bond length, mid-bond electron shows covalent nature of Ag by maximum and minimum charge accumulation. • Spherical morphology provides the high surface to volume ratio. The medicinal plant of Withania somnifera leaf extract (WSLE) was used to synthesize Ag/NiO nanocomposite via the green sol-gel method. The synthesized nanocomposite was analyzed by UV–Vis (DRS), scanning electron microscope (SEM) with EDAX, Fourier transform spectroscopy (FTIR), X-ray diffraction (XRD) spectroscopic techniques. The decreased bandgap of Ag/NiO to 1.92 eV is resulting in the reduced size of nanoscale spherical particles. The grain size of ∼70 nm enhanced the electrochemical properties. The Ag and NiO presence are identified in the FTIR spectrum and their composite formation is confirmed in XRD analysis. Rietveld refinement profiles show the structural parameters and charge density distribution of cubic Ag/NiO nanocomposite. Therefore, as-prepared Withania somnifera incorporated Ag/NiO scrutinized as an electrode material for supercapacitor applications by cyclic voltammetry, chronopotentiometry, and electrochemical impedance spectroscopy and has been conclave as a first report here and it exhibits specific capacitance of 293 F/g at the current density of 0.5 A/g. The cyclic stability reveals that capacitance retention of 88.45% even after 5000 cycles at current density of 2 mA/g. The nanoscale spherical particles with a link of O and S atoms in organic compounds are boosting the electrochemical performance.