Covalently anchored benzimidazole-reduced graphene oxide as efficient electrochemical supercapacitor electrode material

Portable electronic devices have recently garnered significant attention in the realm of flexible energy storage technologies, as improving the energy density of supercapacitors while maintaining stability and high power density remains a considerable challenge. The simple processing of functionalization of graphene provides enormous possibilities for customizing its nanostructure and characteristics for energy storage capabilities. In this study, we present the pioneering synthesis of reduced graphene oxide (rGO) with the help of Delonix regia (DR) flower extract. Subsequently, rGO was subjected to functionalize with heterocyclic benzimidazole (BI) via a nucleophilic substitution reaction, resulting in the formation of the covalently structured BI-rGO nanocomposites, which serve as robust and highly efficient supercapacitor electrodes. The synthesized BI-rGO exhibited higher specific capacitance of 252 µF/g at 1 A g−1 surpassing the performance of rGO (104 µF/g at 1 A g−1) in 1 M H2SO4, as demonstrated by screen-printed carbon electrodes. Impressively, the BI-rGO electrode showcased excellent capacitance retention of 96.6