| AVS 55th International Symposium & Exhibition | |
| Surface Science | Monday Sessions |
| Session SS+NC-MoA |
| Session: | Reactivity at Oxide Surfaces |
| Presenter: | N.G. Petrik, Pacific Northwest National Laboratory |
| Authors: | G.A. Kimmel, Pacific Northwest National Laboratory N.G. Petrik, Pacific Northwest National Laboratory |
| Correspondent: | Click to Email |
The interaction of oxygen with TiO2 is critical for a variety of applications including the photooxidation of organic materials, purification of water and air, and (potentially) photocatalytic water splitting. In this paper, oxygen adsorption on reduced TiO2(110) is investigated using temperature programmed desorption and electron-stimulated desorption.1 At low temperatures, two O2 molecules can be chemisorbed in each oxygen vacancy. These molecules do not desorb upon annealing to 700 K. Instead for 200 K < T < 400 K, the two O2 convert to another species which has four oxygen atoms, i.e. tetraoxygen, that decomposes at higher temperatures. In contrast when only 1 O2 is adsorbed in an oxygen vacancy, the molecule dissociates upon annealing above ~150 K to heal the vacancy in agreement with previous results. These experimental results, which provide a new model for the interaction of oxygen with TiO2(110), are consistent with the recent prediction that O42- is the most stable form of oxygen in bridging oxygen vacancies.2
1 G.A. Kimmel and N.G. Petrik, PRL 100, 196102 (2008).
2 D. Pillay, Y. Wang, and G. S. Hwang, J. Am. Chem. Soc. 128, 14000 (2006).