An Electrochemical and Spectroscopic Characterization of Pencil Graphite Electrodes

The development of low-cost and disposable electrodes for diverse electroanalytical applications is an active area of research. There are a number of reports in the literature on the use of disposable pencil graphite electrodes. However, there has not been a systematic study that compares the physical and electrochemical properties of pencil graphite electrodes and the more commonly used glassy carbon (GC) electrode. In this study, pencil graphite electrodes were characterized by X-ray photoelectron spectroscopy (XPS), Raman spectroscopy, scanning electron microscopy (SEM), and the electron-transfer kinetics for Fe(CN)(6)(3-/4-), Ru(NH3)(6)(3+/2+), Fe2+/3+, and dopamine redox systems. The pencils graphite electrodes tested in this work showed well defined and reproducible voltammetric peaks for all the redox systems studied. The electron-transfer rate of the pencil graphite electrodes was in most cases comparable to that of the more commonly used glassy carbon (GC) electrode. The pencil graphite electrodes should potentially continue to find applications in inexpensive electroanalytical experiments, as well as in diverse electrochemical experiments in teaching laboratories. (C) 2012 The Electrochemical Society. [DOI: 10.1149/2.007209jes] All rights reserved.