Graphene-Like 2D Porous Carbon Nanosheets Derived from Cornstalk Pith for Energy Storage Materials

Biomass materials from different organisms or different parts (even different periods) of the same organism have different microscopic morphologies, hierarchical pore structures and even elemental compositions. Therefore, carbon materials inheriting the unique hierarchical microstructure of different biomass materials may exhibit significantly different electrochemical properties. Cornstalk pith and cornstalk skin (dried by freeze-drying) exhibit significantly different microstructures due to their different biological functions. The cornstalk skin-based carbon (S-carbon) exhibits a thick planar morphology, and the Barrett-Emmett-Teller (BET) surface area is only about 332.07 m(2) g(-1). However, cornstalk pith-based carbon (P-carbon) exhibits a graphene-like 2D porous nanosheet structure with a rough, wrinkled morphology, and the BET surface area is about 805.17 m(2) g(-1). In addition, a P-carbon supercapacitor exhibits much higher specific capacitance and much better rate capability than an S-carbon supercapacitor in 6 M potassium hydroxide (KOH) electrolyte.