Supercapacitor Performance of Sulfonyldibenzene Derivative-Functionalized Graphene Aerogel

Abstract

3D aerogels incorporating functionalized reduced graphene oxide (SUL/rGO) were prepared as a hydrothermal method utilizing graphene oxide (GO) and a sulfonyldibenzene derivative (SUL) as raw materials. The aromatic compound SUL, which contains hydroxyl and sulfonyl groups, was bonded to reduced graphene oxide (rGO) through π−π connections. The obtained composite material exhibited porosity within its structure with improved hydrophilicity, along with excellent electrochemical characteristics. This improvement was ascribed to the specific rGO structure, as well as the pseudocapacitance inherent in SUL, both of which synergistically contribute to improvement in the characteristics of the prepared electrode materials. Also, an analysis was performed employing density functional theory from which the density of states and adsorption energy of SUL on the surface of rGO were computed to further investigate the charge storage process within the prepared composite. The prepared SUL/rGO-2 electrode exhibited the highest specific capacitance value of 388 F/g at a current density equal to 1 A/g. The constructed symmetrical supercapacitor, SUL/rGO-2//SUL/rGO-2, attained an energy density value of 14.55 Wh/kg at a power density equal to 350 W/kg with an exceptional galvanostatic charge−discharge (GCD) cyclic stability equal to 91% following 10 000 cycles. Therefore, this review presents a novel functionalized graphene-based material incorporating hydroxyl and sulfonyl groups, which holds promise in future energy storage applications.