Activated Carbon for Electrochemical Supercapacitor and Water Filter

Abstract

Palm kernel shell and coconut shell have been combined in equal proportion to produce activated carbons for supercapacitor electrode and water filter. Microwave-assisted activation technique was employed for the production at a much shorter time (ranging from 5-10 min) and reduced cost compared to the conventional activation methods. Co-activator (mixture of NaCl and CaCl2) was used to activate the sample for water filter with no added fillers while the sample for supercapacitor electrode was activated with KOH and NiO nanoparticles as fillers. Physical properties (such as density, ash content and moisture content) and Thermo-Gravimetric Analysis (TGA) were carried out to ascertain the quality of the activated carbons. In addition to the microstructural and structural investigations, surface functionalities, adsorption capability and electrochemical properties of the samples were also investigated. The surface chemistry, microstructure, structure and electrochemical properties of the produced activation carbon were investigated employing Fourier Transform Infra-Red (FTIR) Spectroscopy, Scanning Electron Microscopy (SEM), X-Ray Diffraction (XRD), Cyclic Voltammetry (CV) and Electrochemical Impedance Spectroscopy (EIS).The effectiveness of the activated carbon sample for water filter was tested for the removal of organic dye (methylene blue) from water contaminated with the organic dye via adsorption studies using the Freundlich model. Finally, the results; obtained from electrochemical studies, show that the activated carbon for supercapacitor electrode possesses good current response with high value of specific capacitance and it is a promising component for electrochemical devices.