Spongy nitrogen-doped activated carbonaceous hybrid derived from biomass material/graphene oxide for supercapacitor electrodes

Abstract

Carbon derived from low cost agricultural waste material was used as a precursor for the preparation of a spongy-like nitrogen doped activated composite from carbon/graphene oxide via a one-step thermal treatment. N-doping and activation of the carbon/graphene oxide mixture were achieved simultaneously by the treatment of urea and potassium hydroxide at 800 °C. The nitrogen content and ratio between the nitrogen species was controlled by the mass ratio of KOH : carbon. The composite was prepared with a KOH : carbon ratio of 1 which resulted in a moderate surface area (1712.4 m² g⁻¹) and a high nitrogen content (14.51%). The hybrid material gave high specific capacitance (267 F g⁻¹ at 5 mV s⁻¹) and good cycling stability (92.3% capacitance retention after 5000 cycles) in 6 M KOH electrolyte. Hence, the new composite presented in this work can be used as an advanced material for supercapacitor applications.