Making Photo-selective TiO2 Materials by Cation鈥揂nion Codoping: From Structure and Electronic Properties to Photoactivity

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• 作者：Antonio M. M谩rquez ; Jos茅 J. Plata ; Yanaris Ortega ; Javier Fdez. Sanz ; Gerardo Col贸n ; Anna Kubacka ; Marcos Fern谩ndez-Garc铆a
• 刊名：The Journal of Physical Chemistry C
• 出版年：2012
• 出版时间：September 6, 2012
• 年：2012
• 卷：116
• 期：35
• 页码：18759-18767
• 全文大小：518K
• 年卷期：v.116,no.35(September 6, 2012)
• ISSN：1932-7455

文摘

Photoselective oxidation yielding high-added value chemicals appears as a green novel process with potential to be explored. In this study we combine spectroscopic XPS (N 1s and O 1s) and multiwavelength Raman data with density functional theory calculations to explore the structural and electronic properties of W,N-codoped TiO₂ anatase surfaces and interpret the outstanding photocatalytic properties of such a system in partial oxidation reactions. Theoretical calculations allow us to examine several substitutional and N-interstitial configurations at different concentrations of the W,N dopants (similar to those experimentally found), as well as their interaction with structural point defects: Ti cation vacant sites and surface wolframyl species that are required to compensate the extra charge of the W⁶⁺ and N-containing anions. The joint use of theoretical and experimental XPS and Raman tools renders key structural information of W,N-codoped microcrystalline TiO₂ solids. The incorporation of N at substitutional positions of anatase with the concomitant presence of W鈺怬 species introduces localized states in the band gap, a result that is critical in interpreting the chemical behavior of the solids. The combination of the electronic and geometric structural information leads to a simple mechanism that rationalizes the experimentally observed photoactivity and selectivity in partial oxidation reactions.