Abstract The microstructure of metatitanic acid and its transformations to titanium dioxide during calcination have been investigated previously. However, the detailed microstructure of metatitanic acid has not been elucidated. Herein, we report the high-resolution scanning electron microscopy and X-ray powder diffraction determinations of the microstructure of metatitanic acid and its transformation to titanium dioxide during calcination. It is the first time that the detailed microstructure of metatitanic acid and its transformation to rutile titanium dioxide during calcination have been observed and elucidated. A mechanism of the transformation from metatitanic acid to crystalline titanium dioxide during calcination is described. The basic building blocks of metatitanic acid are the ultrafine crystals with an averaged diameter of a few nanometres, and these ultrafine crystals aggregate to form the porous primary particles. The primary particles further agglomerate to form the porous secondary particle. During the calcination, metatitanic acid undergoes size enlargement of ultrafine crystals, anatase–rutile transformation, merge of primary particles, and the crystal growth of titanium dioxide.

中文翻译：

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偏钛酸的显微结构及其向金红石型二氧化钛的转化

摘要 偏钛酸的微观结构及其在煅烧过程中向二氧化钛的转变之前已经进行了研究。然而，偏钛酸的详细微观结构尚未阐明。在此，我们报告了偏钛酸微观结构的高分辨率扫描电子显微镜和 X 射线粉末衍射测定及其在煅烧过程中向二氧化钛的转化。这是第一次观察和阐明偏钛酸的详细微观结构及其在煅烧过程中向金红石二氧化钛的转变。描述了在煅烧过程中从偏钛酸转变为结晶二氧化钛的机制。偏钛酸的基本组成部分是平均直径为几纳米的超细晶体，这些超细晶体聚集形成多孔初级粒子。初级粒子进一步附聚以形成多孔次级粒子。在煅烧过程中，偏钛酸经历超细晶体尺寸增大、锐钛矿-金红石转变、初级粒子合并和二氧化钛晶体生长。