Electron Transfer Kinetics at Single-Layer Graphene/Ionic Liquid Interfaces

Electron transfer kinetics at the single-layer graphene/ionic liquids interfaces have been examined for different common imidazolium-based ionic liquids and ferrocene derivatives. The heterogeneous kinetics are characterized by slow standard charge transfer rates and an unusual low variation of the rate with the applied potential corresponding to charge transfer coefficients lower than 0.1. This behavior is specific to the electrochemistry on a single-layer graphene as we found that the oxidation of the same substituted ferrocenes in the same ionic liquids follows the classical behavior predicted by the Butler-Volmer law. The heterogeneous charge transfer at single-layer graphene/ ionic liquid interface is characterized by a slow standard charge transfer rate and an unusual low variation of the rate with the applied potential corresponding to a transfer coefficient lower than 0.1. image