Interactions of H2O with SrTiO3(100) surfaces

Interactions of H2O with SrTiO3(100) surfaces were investigated using temperature-programed desorption (TPD) spectroscopy. TPD spectra show that water desorbs below 300 K on stoichiometric TiO2–terminated SrTiO3(100) surfaces. TPD features at 200–300 K are attributed to the nondissociative adsorption of H2O on cation sites while the TPD feature at 160 K is assigned to the desorption of multilayer water. However, TPD spectra for H2O on reduced SrTiO3(100) surfaces exhibit additional desorption features at 300–500 K, resulting from the dissociative adsorption of water. Comparisons of TPD spectra for H2O on SrTiO3(100) with unreconstructed TiO2(110) and (100) surfaces reveal a structural influence on the water adsorption and desorption behavior.