The roles of Li⁺ and F⁻ ions in Li–F-codoped TiO₂ system

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• 作者：Hongfu Jiang ; Haiyan Song ; Zuoxing Zhou ; Xingqin Liu ; Guangyao Meng
• 关键词：A. Semiconductors ; A. Oxide ; D. Luminescence ; D. Phase transitions
• 刊名：Journal of Physics and Chemistry of Solids
• 出版年：2007
• 出版时间：October 2007
• 年：2007
• 卷：68
• 期：10
• 页码：1830-1835
• 全文大小：417 K

文摘

An overall comparative study was carried out on Li-doped, F-doped, and Li–F-codoped TiO₂ powders in order to elucidate the roles of Li⁺ and F⁻ ions in photocatalyst. The characteristic data were based on the analysis of XRD, XPS, and PL spectra. The effects of atomic ratio of Li/Ti and F/Ti on the photocatalytic activity were also investigated. As the results, Li doping accelerated the phase formation of rutile in lower temperature while F doping prevented the phase transition from anatase to rutile. Li doping inducted a large amount of O_OH on the surface of TiO₂, while F doping consumed much of O_OH. Li⁺ ions acted as the roles of recombination center of electron–hole pairs while F doping could restrain the recombination of electron–hole pairs on the center of Li⁺ ions. The roles of Li⁺ and F⁻ ions were also confirmed in the experimental section, where the photocatalytic activity of TiO₂ was improved greatly by synergistic reaction of Li⁺ and F⁻ ions.