An economical green route synthesis of carbon spheres derived from kitchen biowastes for supercapacitor application

The increasing energy demands and worsened environmental conditions paved the way for developing materials that can be recycled easily. The huge amount of kitchen bio-waste thrown in the open environment has also led to environmental deterioration. Herein, we have elucidated a facile green route for the synthesis of carbon spheres from kitchen wastes by hydrothermal method. The XRD and FTIR confirmed the presence of carbon spheres while FESEM with EDX depicted the carbon spheres` spherical morphology and elemental composition. BET analysis revealed that the increase in pore volume resulted in a decrease in the electrochemical performance. The electrochemical performances of carbon spheres have been compared through CV, GCD, and EIS studies. Potato peel-derived carbon spheres (P2) showed maximum specific capacitance i.e., 1987.5 F/g at 0.2 A/g current density in 2 M H2SO4 electrolytic solution. The carbon spheres also showed good capacitance retention capability up to 6000 cycles, out of which P2 showed maximum retention capacity (91.66%), inferring their excellent potential as future electrode materials for supercapacitor applications. Graphical abstract