Copper sulfide nanostripe patterns at the Au(111)/electrolyte interface studied by in situSTM

Abstract

One monolayer of Cu was prepared on Au(111) by underpotential deposition from CuSO₄/H₂SO₄ solution and, by two electrolyte exchanges for (i) Cu-free H₂SO₄ and (ii) NaOH/Na₂S solution, exposed to bisulfide. This procedure leads to several incommensurate phases with characteristic stripe patterns. These are irreversibly displaced upon cathodic potential sweeps by different structures, which, after returning to the initial potential, transform into the rectangular Cu_xS phase already known for the sulfidation of a Cu submonolayer on Au(111).