Holey Graphene for Energy Storage

Abstract

Reduced graphene oxide (RGO) with modified morphologies has shown potential application as electrode material for electrochemical capacitors. By creating nanopores within the RGO sheets, the specific surface area of electrode and diffusion of electroactive species can be improved. Here, we present a simple solution based process to make holey graphene from graphene oxide (GO) via microwave (MW) radiations. GO aqueous dispersion prepared by modified Hummer’s method can be converted to RGO via thermal, chemical or photochemical methods. Then, RGO in presence of hydrogen peroxide is irradiated with microwaves. The MW generated OH• radicals etch away the carbon atoms present at the active defective sites on RGO, leaving behind carbon vacancy, which extends to form the nanopores. This holey graphene is characterized using TEM, XPS, BET, Raman & FTIR. Further, the material is used to make an electrochemical capacitor and tested to show improved energy density.