Electrochemical functionalization of graphene nanosheets with catechol derivatives as an effective method for preparation of highly performance supercapacitors

Performance enhancement of supercapacitors has been recently discussed. In this paper a novel and facile procedure for functionalization of graphene with some electroactive molecules is presented. The graphene has been functionalized by catechol-based molecules, which are electroactive molecules with electrochemically reversible properties. The functionalized graphene exhibits very effective pseudocapacitor behaviorfor charge storage. For the first time, with the aim of an electrosynthesis procedure, catechol is covalently attached on graphene sheets. This attachment has been investigated by electrochemical, X-ray photoelectron spectroscopy and attenuated total reflectance methods. Catechol molecules have been attached via formation of etheric and esteric bonds on the surface of graphene. As a result, the functionalized graphene sheets show a reversible electrochemical behavior and can be used as pseudocapacitor electrodes with an excellent stability. The electrochemical results of the prepared electrodes reveal rather high specific capacity of 288 F g−1 at a high current density of 28 A g−1, which shows remarkably enhanced performance for supercapacitor applications.