Photoemission and HREELS study of K adsorption on TiO2(100)

The adsorption of K and coadsorption of O2 on TiO2(100) have been studied using photoemission and high resolution electron energy-loss spectroscopy (HREELS). We compare our results with those of earlier studies of potassium oxides. The energy separations of peaks appearing in photoemission spectra indicate the formation of a peroxide or superoxide at the surface following adsorption of > 1 monolayer of potassium. HREELS results are consistent with this conclusion.