Sustainable development of porous activated carbon from Sargassum wightii seaweed for electrode material in symmetric supercapacitors

Abstract

• Sw-800 was prepared from Sargassum wightii seaweed by chemical activation method. • Sw-800 sample shows a high surface area of about 801.73 m 2 /g. • The Sw-800 electrode delivered 474 F/g at 1 A/g in three electrode system. • The Sw-800 | | Sw-800 device showed an energy density of 13.81 Wh/kg at a power density of 249.82 W/kg. In the present study, a simple, cost-effective preparation of the highly porous Activated Carbon from the Sargassum wightii macroalgae (Sw AC) using a chemical activation approach with KOH. The Sw-AC samples were prepared at different activation temperatures (600 °C, 700 °C and 800 °C). The samples were labelled based on the activation temperature, such as Sw-600, Sw-700 and Sw-800. Further, the as-prepared Sw-ACs were utilized in supercapacitors (SCs) as electrode materials to evaluate the effect of activation temperature and surface area on the energy storage performance of the Sw-AC electrodes. The successful conversion of seaweed into AC was confirmed by various spectral as well as analytical studies. Among the Sw-AC electrodes, the Sw-800 sample showed a high surface area (801.73 m 2 /g) and high specific capacitance in three-electrode measurements (474 F/g at the current density of 1 A/g). Also, the cyclic stability of the electrode was demonstrated to be 93 % up to 8000 GCD cycles. Owing to the improved performance rendered by Sw-800 electrode, which is used for the fabrication of symmetric device (Sw-800 | | Sw-800). The as-fabricated electrode delivered an energy density as well as a power density value of 13.81 Wh/kg and 249.82 W/kg respectively. All these findings proved that the as-prepared Sw-800 from Sargassum wightii seaweed could make a good impact on the creation of low-cost and sustainable electrode materials for SCs.