X-ray photoelectron spectroscopy of oxygen-containing layers formed by a linear potential scan on stepped gold (111) films in aqueous 1 M sulphuric acid

X-ray photoelectron spectroscopy (XPS) data of oxygen-containing layers (O-layers) made on stepped gold (111) film electrodes from aqueous 1 M sulphuric acid by single linear potential scans at 0.10 V s− 1 and 298 K are reported. The potential scan covered from the open circuit potential to anodic switching potential Eas = 2.50 V versus normal hydrogen electrode (NHE) and holding times at Eas in the range 30–300 s. The anodic charge density qa determined from the oxidation and reduction voltammetric scan is in the range 0.20 ≤ qa ≤ 2.5 mC cm− 2. For the potential E = 0.5 V, in the absence of O-layers, the S 2p core level spectrum indicates the presence of sulphate/bisulphate adsorbates. For Eas > 1.3 V, the O 1s core level spectrum involves the contribution from water, OH- and O-species. These spectra are deconvoluted utilising either three or four Gaussian contributions with values of peaked binding energy and full width at half-maximum height (FWMH) in good agreement with expectations. The envelope of these XPS O 1s signals after correction for the contribution of sulphate/bisulphate adsorbates and adventitious carbon approaches the XPS signal that has been reported for the core level spectrum in the O 1s region of oxidised gold surfaces produced by laser pulses at different molecular oxygen pressures. The O/OH concentration ratio in the O-layer increases with Eas ageing time tag and cathodic charge density qc. The hydrous nature of the O-layer, evaluated through the analysis of the core level spectra in the O 1s region, decreases as Eas and tag are increased. Results are interesting to unravel the composition and structure of electrochemically grown O-layers at the surface of the gold substrate, and the influence of the history of these O-layers on the respective XPS features.