In situ NAP-XPS study of plasma-enhanced silver oxidation and reduction reactions

Near ambient pressure-x-ray photoelectron spectroscopy (NAP-XPS) is a less traditional form of XPS that allows samples to be analyzed at relatively high pressures, i.e., at greater than 5000 Pa. NAP-XPS can probe moderately volatile liquids, biological samples, porous materials, and polymeric materials that outgas significantly. In this submission, we show the survey, Ag 3d, C 1s, and O 1s NAP-XPS spectra of a polycrystalline silver sample exposed in situ to different plasma conditions during the analysis. The measurements were performed operando, during plasma treatments at 5 Pa, both in ambient air and in forming gas, a mixture containing 5% hydrogen and 95% nitrogen.