Reaction mechanism and kinetics analysis of the phase transformation of TiO2 from the anatase phase to the rutile phase
Reaction mechanism and kinetics analysis of the phase transformation of TiO2 from the anatase phase to the rutile phase
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DOI：
10.1007/s10854-013-1125-2
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发表时间：
2013-03
期刊：
影响因子：
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通讯作者：
Jeng-Shin Ma;Ming-Chang Wen;Chung‐Hsin Lu
中科院分区：
文献类型：
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作者：
Jeng-Shin Ma;Ming-Chang Wen;Chung‐Hsin Lu
研究了TiO 2由锐钛矿相向金红石相转变的动力学机制。采用热水解法制备了不同pH值的TiO 2粉体。起始溶液的pH值对热水解反应的相变温度有显著影响。随着反应温度的升高，从金红石相到金红石相的转化率增加。紫外可见光谱分析表明，所制备的TiO 2为核-壳结构。通过反应动力学的等温升温过程，确定了从金红石相到金红石相相变过程的控制反应为三维相界控制过程。相变的活化能随起始溶液pH值的增加而增加。
The kinetic mechanism of the phase transformation of TiO2from the anatase phase to the rutile phase was investigated. TiO2powders were prepared with different pH value of the starting solution via the thermal hydrolysis method in this study. The pH values of the starting solutions have significant effects on the phase transformation temperatures of the thermal hydrolysis reaction. As the reaction temperatures were raised, the conversion from the anatase phase to the rutile phase was increased. A core–shell morphology of the prepared TiO2samples was suggested via the signals of the anatase phase and the rutile phase in UV–vis spectrum analysis. Through the isothermal heating process of the reaction kinetics, the controlling reaction in the phase transformation process from the anatase phase to the rutile phase was determined to be the three-dimensional phase boundary controlled process. The activation energy of the phase transformation was increased with an increase in the pH value of the starting solution.