Low resolution Raman spectroelectrochemistry of single walled carbon nanotube electrodes

A new combination of a low-resolution Raman spectrometer with a minipotentiostat is presented in this work to perform in situ Raman measurements during electrochemical experiments with low-cost instrumentation. The instrumental setup has been used to study the electrochemical oxidation of transparent single walled carbon nanotube (SWCNT) films supported on non-conductive substrates. The spectroelectrochemical response provides the dependence of the characteristic signatures of the SWCNT bundles with the applied potential, which is similar to the response observed for SWCNT films deposited on conducting substrates. The evolution of both the electrical current and the Raman features differs considerably for pristine and oxidized films. The spectroscopic data reveal the occurrence of two kinds of irreversible breakdowns, "oxidative burning" and functionalization of the SWCNTs, in addition to reversible p-doping. 2D-correlation has been applied to analyze the evolution of the spectra with potential and has provided more detailed information than expected from a low spectral resolution spectrometer.