Porous graphitic carbon materials prepared from cornstarch with the assistance of microwave irradiation

Abstract

Porous graphitic carbon materials (PGCs) have attracted great interest because of their properties shown in fields such as catalyst supports, electrochemical double layer capacitors, Li-ion batteries, etc. Biomass is a promising resource to produce PGCs, as it is cheap, eco-friendly and renewable. Using cornstarch as raw material, two PGCs (PGC-1 and PGC-2) were prepared by combining microwave-assisted catalytic graphitization and chemical activation. PGC-1 was made from new gelatinized starch and the other (PGC-2) from retrograded starch. The former was mainly composed of graphitic nanocoils. The latter, on the other hand, was more likely to be a product of activated loose packing carbonaceous sheets. Narrowly distributed hierarchical pores were observed in the PGCs. Both of the PGCs were partly graphitized and had large surface areas (353 m2/g for PGC-1 and 686 m2/g for PCG-2). Cyclic voltammetry and electrochemical impedance spectroscopy test showed that they had good capacitive property.