Sustainable high capacitance supercapacitor electrode from biomass-derived iron and copper-doped graphene structures

In this study, BCG (Biochar-based graphene) was functionalized with iron (Fe) and copper (Cu) to enhance its capacitive behaviour and physicochemical properties. The structural, morphological, and surface characteristics were systematically analyzed using XRD, Raman spectroscopy, XPS, SEM, and BET analysis. Electrochemical analysis showed that BCG-Fe (iron-doped biochar-based graphene) achieved a specific capacitance of 187.72 F/g, with an energy density of 6.52 Wh/kg and power density of 2608 W/kg. BCG-Cu (copper-doped biochar-based graphene) exhibited 157.14 F/g, 5.45 Wh/kg, and 1510 W/kg, respectively. The enhanced performance of BCG-Fe is attributed to improved conductivity and redox activity from Fe doping. These results highlight the promise of metal-modified BCG as a scalable, eco-friendly electrode material for energy storage. • Capacitive biochar is produced from orange peel • Catalytic (Fe and Cu) graphitization is used to produce graphitic carbon • Electrochemical exfoliation is used for exfoliation • The BCG-Fe and BCG-Cu exhibited high specific surface area of 428.65 m 2 /g and 323.61 m 2 /g, respectively. • The BCG-Fe and BCG-Cu showed the specific capacitance value of 187.72 F/g and 157.14 F/g, respectively.