Graphene oxide/Activated carbon nano composite with hierarchical pore structure for supercapacitor applications

Abstract

This study explores the synthesis of high-performance electrode material for supercapacitors through the development of a Graphene oxide (GO)/Activated carbon (AC) nanocomposite via KOH activation method. Varying ratios of GO:AC were investigated to determine their impact on performance, with an optimal configuration identified at a ratio of 1:3. Incorporating AC particles resulted in a more dispersed arrangement of GO sheets, thereby enhancing structural porosity and achieving an impressive specific surface area of 664.53 m²g^-1. The optimized GO:AC composite exhibited a hierarchical porous structure, facilitating enhanced electrode-electrolyte interaction, which is essential for enhanced charge storage capacity in supercapacitors. Supercapacitor electrodes were fabricated using the synthesized GO:AC composite on a Fluorine-doped Tin Oxide (FTO) glass substrate using slurry-coating method. Electrochemical characterization was carried out employing a 3-electrode cell configuration with an Ag/AgCl reference electrode and Pt counter electrode. The nanocomposite with 1:3 GO:AC ratio demonstrated specific capacitance of 5.2341 F/cm² (Cyclic Voltammetry) and 473.27 F/g (Galvanostatic Cycling) in 1 M HCl aqueous solution. The electrode of GO/AC has retained over 73.8 % of the initial capacitance after 1000 charge/discharge cycles showing good electrochemical stability. Notably, this synthesis approach offers a straightforward and scalable method for fabricating stable, porous graphene-based electrode architectures, holding significant promise for practical supercapacitor applications.