Crystallization of anatase from amorphous titania using the hydrothermal technique: Effects of starting material and temperature
Crystallization of anatase from amorphous titania using the hydrothermal technique: Effects of starting material and temperature
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DOI：
10.1021/jp990521c
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发表时间：
1999-09-16
影响因子：
3.3
通讯作者：
Ovenstone, J
中科院分区：
文献类型：
--
作者：
Yanagisawa, K;Ovenstone, J
采用水热法对无定形二氧化钛的晶化过程进行了控制。微晶尺寸和表面积可以通过仔细改变水热条件来控制。水对结晶的催化作用已经被证明，并且结晶机理已经被证明随着温度的升高而从固态类型变为溶解沉淀。的非晶前体制备路线的影响已被检查，以评估的结晶过程中的污染物离子的效果。已经表明，即使在干燥条件下，氯离子也会加速结晶的成核。研究了酸性和碱性溶液的影响。酸性条件导致金红石、板钛矿和金红石的形成，而碱性条件加速金红石的产生。讨论了金红石和金红石的水热晶化机理。
The crystallization of anatase from amorphous titania has been controlled using the hydrothermal technique. Crystallite size and surface area can be controlled by careful alterations of the hydrothermal conditions. The catalytic effect of the water on crystallization has been demonstrated, and the crystallization mechanism has been shown to change from a solid-state type to dissolution precipitation as the temperature is increased. The influence of the amorphous precursor preparation route has been examined in order to evaluate the effect of contaminant ions on the crystallization process. It has been shown that the chloride ion accelerates the nucleation of the anatase, even under dry conditions. The effects of acidic and basic solutions have been studied. Acidic conditions result in the formation of anatase, brookite, and rutile, whereas basic conditions accelerate the production of anatase. The mechanisms for the hydrothermal crystallization of anatase and rutile are discussed.