Berlin 2018 – wissenschaftliches Programm
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O: Fachverband Oberflächenphysik
O 55: Focus Session: Structure and Chemistry of Metal-Oxide Surfaces II
O 55.9: Vortrag
Mittwoch, 14. März 2018, 12:45–13:00, MA 005
Determining the structure of nitrogen doped rutile TiO2(110) — •Francesco Allegretti1, Michael Wagstaffe2, David A. Duncan1,3, Tien-Lin Lee3, Johannes V. Barth1, Andrew G. Thomas2, and Rob Lindsay2 — 1Physik-Department E20, Technische Universität München, Germany — 2School of Materials, University of Manchester, United Kingdom — 3Diamond Light Source, Didcot, United Kingdom
Titanium dioxide is the prototypical photocatalyst for water cracking, however its wide band gap (>3 eV) means that it only utilises a small percentage of natural sunlight. One approach to narrowing this band gap, to allow more efficient solar water cracking, is the deliberate doping of TiO2 with impurities [1]. Notably, using nitrogen as the dopant leads to a significant enhancement of the photocatalytic functionality under visible light irradiation [2]. Previous angular scanned photoelectron diffraction measurements [3] have suggested that these N3− ions occupy O2− sites in the bulk unit cell, however the level of agreement, both between O 1s and N 1s core-level data and between theory and experiment was only qualitative. Here we present an X-ray standing wave study of N-doped rutile TiO2(110) that directly demonstrates that the majority of N3− ions do indeed occupy O2− sites, however a minority bulk-like component with strongly different site was also observed.
[1] Z. Wang, et al., Phys. Chem. Chem. Phys. 16, 2758 (2014) [2] J. Tao, et al., J. Phys. Chem. C 118, 994 (2014) [3] M. Batzill, et al., Chem. Phys. 339, 36 (2007)