Sulfur edge XANES and XPS spectroscopy of ethanethiol adsorbed on nickel

For the interaction of ethanethiol (C2H5SH) with the Ni(1 1 0) surface, we utilize X-ray photoelectron spectroscopy (XPS) and X-ray absorption near-edge spectroscopy (XANES) measurements to identify the adsorbed sulfur species and their orientation on the surface at low temperature. Upon adsorption on the Ni(1 1 0) surface, ethanethiolate as well as atomic sulfur is formed. For the ethanethiolate, the S–C bond is found predominantly perpendicular to the substrate as revealed by polarization analysis. A qualitative estimation of charge transfer from substrate to molecule is carried out with the aid of S 1s XPS measurements.