Photochemical studies on N-doped TiO2 single crystals - Fundamental Investigations of Water Splitting on Model TiO2 (Mike Henderson's BES Project - 48526)
EMSL Project ID
19811
Abstract
Development of new energy sources is a major need for the 21st century. Hydrogen has considerable potential as an alternative fuel. The discovery by Fujishima and coworkers in 1969 that water could be photocatalytically split on TiO2 electrodes has motivated research toward development of visible light active photocatalysts. While TiO2 absorbs little of the solar spectrum, cation doping red-shifts the TiO2 absorption spectrum into the visible, but without apparent activity for water splitting. Promising results have emerged recently on a new class of visible-light active TiO2 photocatalysts doped with anions (C, N, S). Emerging research effort has approached anion-doped TiO2 photocatalysis from a phenomenological perspective, placing emphasis on catalyst preparation and performance evaluation, and not on developing a fundamental understanding at the molecular-level. As such, there is a specific opportunity for basic science to provide a solid foundation of understanding of how doping influences the visible-light photocatalytic properties of TiO2 and a general need for a better understanding of the heterogeneous photocatalytic water splitting reaction. We propose examining the fundamental properties of heterogeneous photocatalytic water splitting on ion-doped TiO2 single crystal surfaces (with and without noble-metal loading) in a concerted approach that employs: (a) controlled doping using molecular beam epitaxy and ion implantation, (b) characterization using state-of-the-art techniques, (c) theoretical modeling using DFT methodologies, (d) photochemistry and photodynamics using UHV-based surface science methods, and (e) photocatalytic performance tests.
Project Details
Project type
Large-Scale EMSL Research
Start Date
2006-07-21
End Date
2009-09-30
Status
Closed
Released Data Link
Team
Principal Investigator
Team Members
Related Publications
Du Y, NA Deskins, Z Zhang, Z Dohnalek, M Dupuis, and I Lyubinetsky. 2009. "Imaging Consecutive Steps of O2 Reaction with Hydroxylated TiO₂(110): Identification of HO₂ and Terminal OH Intermediates." Journal of Physical Chemistry C 113(2):666-671.
Du Y, NA Deskins, Z Zhang, Z Dohnalek, M Dupuis, and I Lyubinetsky. 2009. "Two Pathways for Water Interaction with Oxygen Adatoms on TiO2(110)." Physical Review Letters 102(9):Art. No. 096102. doi:10.1103/PhysRevLett.102.096102
Henderson MA. 2008. "Effect of Coadsorbed Water on the Photodecomposition of Acetone on TiO2(110)." Journal of Catalysis 256(2):287-292. doi:10.1016/j.jcat.2008.03.020
N.G. Petrik, Z. Zhang, Y. Du, Z. Dohnálek, I. Lyubinetsky, and G.A. Kimmel, "The Chemical Reactivity of Reduced TiO2(110): The Dominant Role of Surface Defects in Oxygen Chemisorption", J. Phys. Chem. C 113 (2009) 12407.
S.A. Chambers, T. Ohsawa, C.M. Wang, I. Lyubinetsky, and J.E. Jaffe, "Band Offsets at the Epitaxial Anatase TiO2/n-SrTiO3(001) Interface", Surf. Sci. 603 (2009) 771-80.
S.-C. Li, Z. Zhang, D. Sheppard, B.D. Kay, J.M. White, Y. Du, I. Lyubinetsky, G. Henkelman, and Z. Dohnálek, "Intrinsic Diffusion of Hydrogen on Rutile TiO2(110)", JACS 130 (2008) 9080-8.
Takeo Ohsawa, Michael A. Henderson and Scott A. Chambers, ?Epitaxial growth and orientational dependence of surface photochemistry in crystalline TiO2 rutile filmes doped with nitrogen?, J. Phys. Chem. C 114, 6595 (2010).
T. Ohsawa, I. Lyubinetsky, Y. Du, M.A. Henderson, V. Shutthanandan, and S.A. Chambers, "Crystallographic Dependence of Visible-Light Photochemistry in Epitaxial TiO2-xNx Anatase and Rutile", Phys. Rev. B 79 (2009) 085401.
T. Ohsawa, I.V. Lyubinetsky, M.A. Henderson, and S.A. Chambers, "Hole-Mediated Photodecomposition of Trimehtylacetate on a TiO2(001) Anatase Epitaxial Thin Film Surface", J. Phys. Chem. C 112 (2008) (50) 20050?20056.
Y. Du, N.A. Deskins, Z. Zhang, Z. Dohnálek, M. Dupuis, and I. Lyubinetsky, Formation of O Adatom Pairs and Charge Transfer upon O2 Dissociation on Reduced TiO2(110), Phys. Chem. Chem. Phys. 12 (2010) 6337
Y. Du, Z. Dohnálek, and I. Lyubinetsky, "Transient Mobility of Oxygen Adatoms upon O2 Dissociation on Reduced TiO2 (110)", J. Phys. Chem. C 112 (2008) 2649-53.
Z.Q. Yu, C.M. Wang, Y. Du, S. Thevuthasan, and I. Lyubinetsky, "Reproducible Tip Fabrication and Cleaning for UHV STM", Ultramicroscopy 108 (2008) 873-7.
Z. Zhang, Y. Du, N.G. Petrik, G.A. Kimmel, I. Lyubinetsky, and Z. Dohnálek, "Water as a Catalyst: Imaging Reactions of O2 with Partially and Fully Hydroxylated TiO2(110) Surfaces", J. Phys. Chem. C 113 (2009) 1908?1916.