Surface characteristics and microstructure of dispersed TiO₂ nanoparticles prepared by diffusion flame combustion

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• 作者：Yin Zhao ; Chunzhong Li ; Xiuhong Liu ; Feng Gu ; H.L. Du ; Liyi Shi
• 关键词：Titanium dioxide ; Nanoparticles ; Gas flame combustion ; Oxygen vacancies ; Crystal structure
• 刊名：Materials Chemistry and Physics
• 出版年：2008
• 出版时间：15 February 2008
• 年：2008
• 卷：107
• 期：2-3
• 页码：344-349
• 全文大小：780 K

文摘

Via properly changing concentration of titanium precursor, tuning the residence time and controlling of the temperature field in the reaction region, nanocrystalline TiO₂ powders were synthesized by the diffusion flame method with well-dispersed behavior and controlled crystal structures and particles size. The XPS and IR results showed that there existed high hydration and oxygen vacancies on the surface of the as-prepared nanocrystalline TiO₂ powders, which played a dominant role in controlling polymorph fraction by altering the critical particles size of phase transition. The thermodynamics analysis demonstrated that the high hydration on TiO₂ surface can produce the lattice contraction, which effectively stabilizes anatase phase. However, the oxygen vacancies on TiO₂ surface can decrease activation energy of phase transition of anatase to rutile, which facilitates the phase transformation.