Electrical and structural properties of stepped, partially reconstructed Au(11n) surfaces in HClO4 and H2SO4 electrolytes

► Au(11n) surfaces prepared either in ultra-high vacuum or by flame annealing in air display an extremely wide terrace width distribution. When immersed into an electrolyte at potentials negative of the potential of zero charge the voltammograms during a positive sweep are extremely complex. ► The complex, yet reproducible, voltammograms as well as their dependence on the scan speed have been explained quantitatively by a model that involves three different types of reconstruction. Two of them can be identified as the reconstructions on extended flat (100) terraces and on 5-25 nm wide terraces, respectively. The third type of reconstruction is associated with terraces that are too small to accommodate the normal hex-reconstruction and a reconstruction free zone at the steps. ► The gains in surface free energy due to the three types of reconstruction have been determined from experiment.