Scanning tunneling microscopy of laser‐activated carbon electrodes used in studies of electrochemical charge‐transfer reactions

Carbon electrodes form the basis of a variety of electroanalytical sensors, in part due to their low cost, wide potential range, and suitability for modification. A major research effort is underway in many laboratories to understand better the properties of carbon electrodes regarding electrocatalytic activity and other factors such as background current and electron transfer activity. One method of improving the performance of these electrode materials involves the application of pulses from a Nd:YAG or N2 laser, either during or prior to electrochemical use. Both electrochemical and spectroscopic probes indicate dramatic changes to the surface of the electrodes after the pulses. Raman spectroscopy of the electrode surface indicates damage to the carbon lattice, with an increase in intensity of the Raman band at 1360 cm−1. This band is active in crystallites of finite size, and indicates increased exposure of graphitic edge plane. Also, there is a dramatic increase (≥106×) in heterogeneous charge‐transf...