Potential dependent surface Raman spectroscopy of single wall carbon nanotube films on platinum electrodes

The analysis of the resonance Raman spectra of single-walled carbon nanotubes in an electrochemically controlled aqueous H2SO4 environment using different laser excitation energies shows major reversible and irreversible differences in the main vibrational features regarding their intensities, lineshapes, and frequencies for different applied potentials. These differences arise from the electrochemically induced changes in the occupation of electronic states for metallic and semiconducting nanotubes.