A green and economical approach to derive biomass porous carbon from freely available feather finger grass flower for advanced symmetric supercapacitors

Presently, the porous carbon derived from natural biomass wastes hold a prominent position as electrode material in supercapacitors from its wonderful features of huge surface area, cost-effectiveness, freely available precursor, easy to preparation and eco-friendly nature. Thus, in the present study, we propose a new hollow tubular-like porous carbon (HT-PC) from the more sustainable and freely available feather finger grass flower (FFGF) with high electrochemical behavior as an active electrode for supercapacitors. The combination of carbonization and KOH activation treatments were carried out to prepare HT-PC from natural FFGF. The as-prepared biomass HT-PC containing the different sized micro-pore arrangement with a huge surface area (637.1 m(2) g(-1)) after performed KOH activation treatment at the optimized condition. The three-electrode system measurements reveal that as-prepared HT-PC provides a remarkable specific capacitance of 315 F g(-1) at 1 A g(-1) and 262 F g(-1) at 100 A g(-1) with keeping 96% of capacitance over 50,000 cycles at 50 A g(-1) using 6 M KOH aqueous electrolyte. In addition to that, the HT-PC electrode-based symmetrical supercapacitor releases high specific energy of 18.75 Wh kg(-1) at 0.37 kW kg(-1) with losing 30% of capacitance over 10,000 cycles at 10 A g(-1) using 6 M KOH electrolyte. Meanwhile, the symmetrical supercapacitor shows a good specific energy of 13.18 Wh kg(-1) at 0.61 kW kg(-1) without losing any capacitance over 10,000 cycles at 10 A g(-1) using 1 M Et4NBF4/AN electrolyte. This study is verified that the naturally available FFGF is a talented sustainable carbon source to make more economical and effective carbon electrodes for supercapacitors.

Automated summary

This study demonstrates the use of a new hollow tubular-like porous carbon (HT-PC) derived from feather finger grass flower (FFGF) as an electrode material for supercapacitors, showing high electrochemical performance, stable cycling, and excellent specific capacitance.