Metal-electrolyte boundary studies with in situ photoemission

The boundary between copper (111) and 0.5 M H2SO4 is investigated using interfacial photoemission spectroscopy. Exploiting knowledge of electron momentum restrictions a feature in the ratio of p-polarized to s-polarized photoelectron yield was correlated with the onset of transitions to Bloch-like final states within the metal at 4.1 eV. This provide some energy specification in the electron energy integrated yield data. The quality of the interface was monitored using both clean and adsorbate (thiourea) covered Cu surfaces. The major effect of adsorption is attributed to a loss of conversation of electron momentum parallel to the surface during the emission process.