Investigation of the pH response of single carbon fibre electrodes

Abstract

The potentiometric response of single carbon electrodes was examined in the titration of hydrochloric acid with potassium hydroxide. The electrodes were prepared either from two types of commercially available carbon fibre samples or from samples that were surface treated in the laboratory. Each carbon fibre electrode was examined by anodic voltammetry. This method was capable of showing that the presence of oxidisable surface groups could be altered by the prior surface treatment. Although the anodic voltammograms were different for each kind of surface treatment, the effect on the shape of the potentiometric curves was slight. It is suggested that there is an instability of the surface groups on carbon fibre.