H2O adsorption and dissociation on defective hematite (0001) surfaces:: A DFF study

The interaction of absorbed water with defected hematite surfaces is studied in low-coverage. Three point-defective surfaces, including an Fe-vacancy, an Fe-adatom site, and an O-vacancy were studied using periodic density functional theory in a periodic slab model. The 2-coordinated O around an Fe-adatom or vacancy shows a decreased electron occupation. As a result, the defective surfaces with Fe-adatoms and vacancies are more reactive for H2O than either clean or O-vacancy surfaces. The Fe-adatom surface is most reactive for H2O molecular adsorption and is also highly reactive for dissociative adsorption. (C) 2008 Elsevier B.V. All rights reserved.