Electrochemical behavior of rigid carbon nanotube composite electrodes

The electrochemical performance of different carbon nanotube epoxy composites was characterized. In particular, the electrochemical behavior of composites made of bamboo-like, single and multi-walled carbon nanotubes of different diameters has been studied, and compared with reference materials such as analog graphite composites and HOPG (basal and edge). The analysis has been focused on the electron transfer rate constants and charge transfer resistances determined by cyclic voltammetry and impedance spectroscopy. The results were also complemented with surface conductance mappings by atomic force microscopy (AFM) in the current sensor mode. The results suggest that the density of edges is the main parameter controlling the good electrochemical performance of the composite transducers. A remarkable characteristic of the CNT composites is a good signal to noise ratio (sensitivity) due to relatively low background currents, in contrast to other nanotube-based transducers such as SWNT bucky paper. (C) 2008 Elsevier B.V. All rights reserved.