Gracilaria edulis seaweed derived nitrogen, oxygen, and sulfur self‐doped biocarbon materials for supercapacitor applications: An investigation on the impact of acid washing and activation

Abstract

AbstractSeaweed biomass of Gracilaria edulis was effectively converted into biocarbon materials at 800°C for 1 hour under nitrogen gas flow atmosphere. The effect of HCl acid washing and ZnCl2‐assisted chemical activation process on the physicochemical and capacitive performances was investigated and the obtained results were compared with their pristine counterpart. The formation of N, O, and S self‐doped biocarbon materials from G. edulis biomass was confirmed by carbon, hydrogen, nitrogen, and sulfur (CHNS), scanning electron microscopy‐energy dispersive X‐ray (SEM‐EDX) and X‐ray photoelectron spectroscopic (XPS) analyses. Further, the specific surface area of acid‐washed and activated biocarbon materials were respectively found to be 1100 and 774 m2 g−1, which are much greater than their pristine counterpart (111 m2 g−1). The obtained pristine (GE‐PC), acid‐washed (GE‐AWC), and activated (GE‐AC) biocarbon materials were effectively explored as the electrode material for symmetric supercapacitor and showed the specific capacitance value of 33.9 (GE‐PC), 58.3 (GE‐AWC) and 76.5 (GE‐AC) F g−1 at 1 A g−1 using 1 M KOH electrolyte.