The role of band structure in electron transfer kinetics in low-dimensional carbon

The role of band structure in heterogeneous electron transfer kinetics at graphene and carbon nanotube electrodes is discussed within Gerischer-Marcus model. Raman spectroscopy was used to estimate the averaged density of defects in anodized epitaxial graphene, single-walled carbon nanotube mats, and multi-walled carbon nanotube carpets. Comparison of the density of defects with cyclic voltammetry data reveals correlation between the defect induced electronic states near the Fermi level and electrochemical efficiency. Electron transfer at low dimensional carbon electrodes is additionally enhanced by layer curvature and doping. Results show that defect induced states are responsible for large dispersion of heterogeneous electron transfer rate constant at different graphitic nanocarbon electrodes.