Facile ZnO-based nanomaterial and its fabrication as a supercapacitor electrode: synthesis, characterization and electrochemical studies

Abstract

In recent times, tremendous efforts have been devoted to the efficient and cost-effective advancements of electrochemically active metal oxide nanomaterials. Here, we have synthesized a facile nanomaterial of ZnO@PdO/Pd by employing extracted fuel from <i>E. cognata</i> leaves following a hydrothermal route. The phyto-fueled ZnO@PdO/Pd nanomaterial was fabricated into a supercapacitor electrode and was scrutinized by galvanostatic charge-discharge, electrochemical impedance spectroscopy and cyclic voltammetry to evaluate its energy storage potential, and transport of electrons and conductivity. Substantial specific capacitance <i>i.e.</i>, 178 F g^-1 was obtained in the current study in aKOH electrolyte solution. A specific energy density of 3.7 W h Kg^-1 was measured using the charge-discharge data. A high power density of 3718 W Kg^-1 was observed for the ZnO@PdO/Pd electrode. Furthermore, the observed low internal resistance of 0.4 Ω suggested effective electron- and ion diffusion. Thus, the superb electrochemical behavior of the ZnO@PdO/Pd nanocomposite was exposed, as verified by the significant redox behavior shown by cyclic voltammetry and galvanostatic charge-discharge.