Study of surface fluorination of photocatalytic TiO₂ by thermal shock method

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• 作者：Tien Khoa Le^a ; ^b ; Delphine Flahaut^a ; ^{delphine.flahaut@univ-pau.fr} ; Dominique Foix^a ; Sylvie Blanc^a ; Huu Khanh Hung Nguyen^b ; Thi Kieu Xuan Huynh^b ; Herv&#233 ; Martinez^a
• 关键词：Fluorinated TiO2 ; Structure characterization ; XPS ; Photocatalytic activity
• 刊名：Journal of Solid State Chemistry
• 出版年：2012
• 出版时间：March 2012
• 年：2012
• 卷：187
• 期：Complete
• 页码：300-308
• 全文大小：760 K

文摘

Surface fluorinated TiO₂ powders were prepared by thermal shock method and an overall comparative study was achieved on the basis of XRD, SEM, UV-vis and XPS analyses. The main objective was to elucidate the influences of surface fluorination on the crystallite structures, morphologies, optical properties and surface chemistry with the temperature. According to the results, the surface fluorination under thermal shock method below 600 ¡ãC did not change the crystallite structure and the particles size, but successfully created chemisorbed fluoride ions, oxygen vacancies and increased the hydroxyl groups on the surface of TiO₂. The presence of oxygen vacancies was assigned to the red shift of TiO₂ optical absorption edge, which was the origin of visible-light-induced photocatalytic activity of these samples. For the thermal shock temperatures over 600 ¡ãC, the K₂Ti₆O₁₃-like phase was formed, resulting from the decrease of surface hydroxyl groups and the blue shift in absorption edge which reduced the photocatalytic activity.