Hierarchical porous graphene nanosheets derived from moso bamboo with superior supercapacitor performance

Moso bamboo is regarded as a kind of biomass resource with abundant reserves in nature, and how to achieve its high-value utilization is one of the important research topics widely concerned by the academic community. In this work, hierarchical porous graphene nanosheets with wrinkled structures derived from the natural moso bamboo is obtained via a compact two-step processing method including pyrolysis and chemical activation. The as-prepared ABC-950 possess a large specific surface area of 1758 m2 g-1, pore volume of 1.55 cm3 g- 1, mesopores ratio of 75.5 % and high graphitization degree with ID/IG as low as 0.43. With these merits, as the electrode material for supercapacitor, the ABC-950 exhibits a high specific capacitance of 459.4 F g-1 at 1 A g-1 and an excellent rate performance of 82.3 % in 6 M KOH electrolyte. Moreover, the ABC-950 based symmetric supercapacitor shows superior specific capacitance of 112.3 F g-1 at 0.5 A g-1 and an attractive energy density of 15.6 Wh & sdot;kg- 1 at 250 W kg- 1. Moreover, outstanding capacitance retention of about 102.1 % even after 30,000 charge-discharge cycles at a large current density of 10 A g-1. Our work offers a promising method to easily transform moso bamboo into porous graphene nanosheets for the electric energy storage.