Three-dimensional aerogel on sulfonyldibenzene derivative functionalized reduced graphene oxide for aqueous supercapacitor

Three-dimensional aerogels utilizing functionalized reduced graphene oxide (SUL/rGO) were synthesized through a hydrothermal approach, employing a sulfonyldibenzene derivative (SUL) and graphene oxide (GO). The aromatic organic molecule SUL, containing sulfonyl and hydroxyl groups, was connected to reduced graphene oxide (rGO) by π-π interactions. The resulting composite displayed enhanced hydrophilicity, a porous structure, and good electrochemical performance. This enhancement stemmed from the pseudocapacitance inherent in SUL and the specific structure of rGO, both synergistically contributing to the electrode materials. Furthermore, employing density functional theory, the adsorption energy and density of states of SUL on the rGO surface were calculated to provide additional insights into the charge storage mechanism of SUL on rGO. The SUL/rGO electrode demonstrated a maximum specific capacitance of 388 F/g at a current density of 1 A/g. The assembled SUL/rGO-2//SUL/rGO-2 symmetrical supercapacitor achieved an energy density of 14.55 Wh/kg at a power density of 350 W/kg, and satisfactory GCD cycle stability of 91% after 10,000 cycles. This study proposes a novel functional graphene incorporating sulfonyl and hydroxyl groups, a promising material for energy storage devices.