Influence of nitrogen doping on the defect formation and surface properties of TiO2 rutile and anatase.
Nitrogen doping-induced changes in the electronic properties, defect formation, and surface structure of TiO2 rutile(110) and anatase(101) single crystals were investigated. No band gap narrowing is observed, but N doping induces localized N 2p states within the band gap just above the valence band. N is present in a N(III) valence state, which facilitates the formation of oxygen vacancies and Ti 3d band gap states at elevated temperatures. The increased O vacancy formation triggers the 1 x 2 reconstruction of the rutile (110) surface. This thermal instability may degrade the catalyst during applications.
Department of Physics, Tulane University, New Orleans, Louisiana 70118, USA.
Matthias
M
Batzill
Erie H
EH
Morales
Ulrike
U
Diebold