About the Nitrogen Location in Nanocrystalline N-Doped TiO2: Combined DFT and EXAFS Approach

• Published in: Journal of physical chemistry. C 2012-01, Vol.116 (2), p.1764-1771
• Main Authors: Ceotto, Michele, Lo Presti, Leonardo, Cappelletti, Giuseppe, Meroni, Daniela, Spadavecchia, Francesca, Zecca, Roberto, Leoni, Matteo, Scardi, Paolo, Bianchi, Claudia L, Ardizzone, Silvia
• Format: Article
• Language: English
• Subjects: C: Nanops and Nanostructures; Condensed matter: electronic structure, electrical, magnetic, and optical properties; Condensed matter: structure, mechanical and thermal properties; Cross-disciplinary physics: materials science; rheology; Electron states; Electronic structure and electrical properties of surfaces, interfaces, thin films and low-dimensional structures; Electronic transport phenomena in thin films and low-dimensional structures; Exact sciences and technology; Low-dimensional structures (superlattices, quantum well structures, multilayers): structure, and nonelectronic properties; Materials science; Methods of electronic structure calculations; Nanocrystalline materials; Nanoscale materials and structures: fabrication and characterization; Physics; Surfaces and interfaces; thin films and whiskers (structure and nonelectronic properties)
• ISSN: 1932-7447; 1932-7455
• DOI: 10.1021/jp2097636

N-doped titanium dioxide is one of the most promising materials for photocatalysis in the visible region. The exact location of nitrogen in the host lattice is still under debate. Here, we synthesized a series of N-doped titania nanoparticles. Average Ti nearest neighbors distances were obtained from EXAFS experiments and compared with DFT calculations at different levels of theory. The comparison shows that N substitutes oxygen at low levels of doping, whereas oxygen vacancy creation is observed at higher dopant concentrations. Overall, this article illustrates a general method for bulk characterization based on DFT and EXAFS approaches, which can be extended to several systems.