Redox reaction of p-aminophenol at carbon nanotube electrodes is accelerated by carbonaceous impurities

We show here that the enhanced electrochemical behaviour of carbon nanotubes towards the redox reactions of p-aminophenol does not stem from the innate properties of carbon nanotubes. Investigating the isolated effect of each component present within carbon nanotubes samples, which are the carbon nanotube, the graphitic and amorphous carbonaceous impurities and the metallic impurities, we have elucidated that solely the carbonaceous impurities, both graphitic and amorphous, significantly accelerate the electron transfer reaction of p-aminophenol at carbon nanotube surfaces.