Nickel Oxide Integrated With Activated Carbon Derived From Areca Nut Husk Biomass Waste as a Potential Electrode for Supercapacitors

Abstract

The rising demand for sustainable energy storage highlights the importance of using renewable biomass as carbon‐based electrodes for supercapacitors. However, optimizing these materials by tuning kinetics, surface area, and pore size is challenging. Globally, over half a million tons of areca nut husk waste are generated annually. This study demonstrates nickel oxide integrated with biomass waste areca nut husk derived activated carbon (Ni x O y ‐AC) as a supercapacitor electrode. Comprehensive structural and electrochemical characterizations are performed. Fabricated via a facile route at low temperature, Ni x O y ‐AC contains amorphous carbon and crystalline Ni 2 O 3 , while it has Ni 2+ , Ni 3+ , Ni─O, C─O, C─C, C═C, and C═O bonds. The material possesses micropores with a specific surface area of 272.204 m 2 g −1 and an average pore diameter of 1.769 nm. The material exhibits pseudocapacitive characteristics and high electrical conductivity. The gravimetric specific capacitance is approximately 348 F g −1 in 6 M KOH. Furthermore, the electrode exhibits a capacitance of 103 F g −1 at a high current density of 3.5 A g −1 , delivering an energy density of 1.43 Wh kg −1 at a power density of 1049.446 W kg −1 . This performance is attributed to its unique structure, abundant redox active sites, and improved electronic conductivity.