Electrocatalysis with reduced graphene oxide. Electron shuttling between redox couples anchored on a 2D surface

The electron storage and shuttling capabilities of reduced graphene oxide (RGO) have been explored by anchoring two redox couples, methyl viologen (MV2+) and ferrocene (Fc). When an RGO modified glassy carbon electrode (GCE/RGO) was subjected to a cathodic scan, a quasi-reversible reduction of MV2+ was seen indicating a loss of electrons contributed to "charging" of RGO. These stored electrons can then be transported to oxidized Fc during the anodic scan through the C–C network of RGO. The recycling and peak current magnitude of oxidized and reduced forms of Fc during the anodic scan is strongly dependent on the scan rate, concentration, and extent of MV2+ reduction, either complete or partial, during the cathodic scan. This electrocatalytic property of RGO film enables the design of sensors and catalysts with the capacity to capture, store, and shuttle electrons and corroborate a boost in sensitivity for the electrochemical detection and conversion of low level analytes.