The Kinetics of the (√3×√3)R30° Sulfur Lattice Stripping from Au(111):  Competitive Desorption−Hole Nucleation and Growth Model

The stripping of the underpotential deposited (√3×√3)R30° sulfur lattice from Au(111) surfaces is studied by electrochemical techniques complemented with in situ scanning tunneling microscopy. The kinetics of the stripping process fits a model where adsorption/desorption competes with nucleation and growth of two-dimensional holes under charge transfer control. We propose that two phases compete for the electrode surface: a condensed phase consisting of holes nucleated at defects of the adsorbed layer and a diluted phase consisting of randomly distributed vacancies produced by desorption. The relative contribution of each process depends on the applied potential and the step density of the substrate.