Electron Transfer Kinetics on Mono- and Multi-Layer Graphene
Herein, the electrochemical response of mono-layer and multi-layer graphene electrodes, prepared using both chemical vapour deposition and mechanical exfoliation, is presented. Experiments were carried out using a microinjector, micromanipulator and optical microscopy, enabling precise deposition of size-controlled droplets on the flake surface.1 The insulating substrates used for flake preparation include inorganic materials and organic polymers. Graphene/graphite flakes were characterised using optical microscopy, Raman spectroscopy and atomic force microscopy.
The electron transfer rate at the basal planes, edge planes and boundaries between graphene flakes was determined using voltammetric techniques. The redox couple, number of graphene layers, presence of defects and nature of the substrate are all shown to have a significant effect on the electrochemical activity.2-3 Furthermore, the stability of the droplets on the surface depends on various factors, such as the solvent choice, electrolyte content, number of graphene layers, underlying substrate and method of flake preparation.
1. Valota, A. T.; Toth, P. S.; Kim, Y. J.; Hong, B. H.; Kinloch, I. A.; Novoselov, K. S.; Hill, E. W.; Dryfe, R. A. W., Electrochimica Acta, 2013, 110, 9-15.
2. Valota, A. T.; Kinloch, I. A.; Novoselov, K. S.; Casiraghi, C.; Eckmann, A.; Hill, E. W.; Dryfe, R. A. W., ACS Nano, 2011, 5 (11), 8809-8815.