Coconut Husk Waste‐Derived Nitrogen‐Doped Mesoporous Carbon Nanomaterial as an Efficient and Sustainable Supercapacitor

Abstract

Sustainability and waste management are equally important in the era of growing energy demands. This study focuses on integrating strategies that balance energy efficiency, reduce waste generation, and promote sustainable practices. The coconut husk is processed and converted into mesoporous carbon nanomaterial through hydrothermal‐assisted thermal annealing. Nitrogen is doped through melamine to increase reactive sites and hence the catalytic activity. The sphere‐like morphology was confirmed by field emission scanning electron microscope and high‐resolution transmission electron microscope  images indicate a carbon dot‐like structure. The high Brunauer‐Emmett‐Teller surface area achieved for this nanostructure is 1383.40 m2 g−1, with pore width and volume at 2.2660 nm and 0.2995 cm3 g−1, respectively. The as‐synthesized nanostructure is explored for its electrochemical performance as electrodes for the supercapacitor application, where materials achieve a wide potential window (−1.4 to 1.4 V) in the minimum time of 50 s at the current density of 0.6 A g−1. Moreover, the highest specific capacitance obtained from the nanomaterial is 115.39 F g−1 in the potential window and current density of 2 V and 0.6 A g−1, respectively. The energy density, power density, and coulombic efficiency at the set parameter are 62.31 Wh Kg−1, 1166.4 W Kg−1, and 79.61%, respectively. Finally, the practical device is assembled with the nanomaterial, where a red LED bulb glows after 1 min of charging.