Comparison of TiO2(110) Surfaces by XPS: Effects of UV Exposure, Electron Beam and Ion Beam Damage

Many studies have been carried out on rutile TiO2 since it was discovered to be a photocatalyst with relatively high efficiency for the decomposition of water. Surface defects are believed to play an important role in dissociation of absorbed water and other small molecules. Defects created on a TiO2(110) surface by thermal annealing in vacuum, or by low-density electron beam irradiation, ultraviolet illumination, and Ar+ ion bombardment, were examined by x-ray photoelectron spectroscopy (XPS). The XPS multiplex spectra of O 1s and Ti 2p peaks were collected. The experiment was carried out in a Perkin-Elmer Physical Electronics 560 Multiprobe surface analysis system with a double pass cylindrical mirror analyzer. Nonmonochromated Mg Kα x-rays were used to generate the spectra.