Hierarchically porous activated carbons derived from Schefflera octophylla leaves for high performance supercapacitors

Hierarchically porous activated carbons with high specific surface areas are synthesized by chemical activation of the leaves of Schefflera octophylla. The specific surface areas of the materials are over 2300 m2 g−1 and the specific pore volume is as high as 1.92 cm3 g−1. The optimized material achieves a high specific capacitance of 336 F g−1 in 6 M KOH aqueous electrolyte at a current density of 0.5 A g−1, and it also shows excellent cycling stability with 97.5% capacitance retention after 10,000 cycles at a current density of 10 A g−1. The simple synthesis route of hierarchically porous activated carbon from renewable bio-wastes enables a promising strategy in both reducing wastes and producing useful energy storage materials.