Graphene covalently functionalized by cross-linking reaction of bifunctional pillar organic molecule for high capacitance

Abstract

The present work reports a pillared graphene network (PGN) synthesized through a cross-linking reaction between bifunctional pillar organic molecules and graphene layers. The resultant pillared graphene network can offer additional active sites for energy storage. More importantly, 2,6-Diaminoanthraquinone (DAAQ) which is covalently grafted onto graphene sheets as a supporting pillar will contribute pseudocapacitance to the overall capacitance. The electrode based on the DAAQ covalently-pillared graphene network (DAAQ-PGN) can deliver a high specific capacitance of 522 F g − 1 at a scanning rate of 5 mV s − 1, which is much greater than that of barely reduced graphene oxide (RGO, 224 F g − 1 at a scanning rate of 5 mV s − 1). Additionally, the DAAQ-PGN provides an electrical conduction path cross graphene layers using the π-conjugated system. This work provides the new ideas for the development of supercapacitors materials in the electronics field.