Electrochemical performances of activated carbon prepared using eggshell waste

Abstract

This paper describes the preparation of activated carbon (Ac) from broiler hen eggshell (BES) and Country hen eggshell (CES) waste with the assistance of chemical activating agent orthophosphoric acid (H3PO4) and eggshell powder for 4:1 and 4:2 concentrations. XRD analysis affirmed the formation of Ac and the hexagonal structure of CaCO3 for both BES and CES samples. The average crystalline size, dislocation density, microstrain, lattice parameter, and cell volume values are found to be higher for CES. The FTIR spectra confirmed the presence of functional groups of BES and CES samples of Ac. UV-DRS spectra exhibited strong absorption in the visible region for BES and the bandgap value is found to be around 1.2 eV for both BES and CES. The surface morphology reveals the porous nature, irregular shape and uniform size particles of Ac. Cyclic voltammetry and electrochemical impedance spectroscopy measurements were performed to study the energy storage application. Though both BES and CES have showed the capacitive behavior, the sample BES exhibit higher specific capacitance of 155.8 F/g is achieved for BES than CES. Similarly, the Rs and Rct values are calculated from the impedance measurement and it is found to be lower for BES sample that indicates improved electrical conductivity.