Voltammetric reductive desorption characteristics of alkanethiolate monolayers at single crystal Au(111) and (110) electrode surfaces

This note describes the results of a comparative study of the reductive desorption characteristics of alkanethiolate monolayers at single crystal Au(111) and Au(110) electrodes. The voltammetric data reveal that the reductive desorption potential is dependent on the surface crystallinity of the underlying gold substrate. The observed difference in potential between these two substrates is indicative of a difference in binding strength of the monolayer at different binding sites in which the gold-sulfur bonding is stronger at the Au(110) than at the Au(111) single crystal. Spectroscopic data (X-ray photoelectron and infrared reflection spectroscopies) provide additional comparisons for the monolayer structures at the two substrates. These findings substantiate our recent study on the voltammetric differences between the atomically smooth surfaces of annealed Au(111) films and the micro-topographically rougher as-evaporated Au(111) films.