Preparation of Crystalline TiO<TEX>$_2$</TEX> Ultafine Powders form Aqueous  TiCl<TEX>$_4$</TEX> Solution by Precipitation Method

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J. Korean Ceram. Soc. > Volume 35(4); 1998 > Article

Journal of the Korean Ceramic Society 1998;35(4): 325.

TiCl$_4$ 수용액에서 침전법에 의한 결정상 TiO$_2$ 초미분체 제조

김선재, 정충환, 박순동, 권상철, 박성¹

한국원자력연구소 원자력재료기술개발팀
¹명지대학교 무기재료공학과

Preparation of Crystalline TiO$_2$ Ultafine Powders form Aqueous TiCl$_4$ Solution by Precipitation Method

ABSTRACT

Crystalline TiO2 ultrafine powders were prepared simply by heating and stirring aqueous TiOCl2 solution with {{{{ {Ti }^{4+ } }} concentration of 0.5 M from room temperature to 10$0^{circ}C$ under 1 atmoshpere. The crystallinity and the particle shape of TiO2 ultrafine powders obtained by simple precipitation method were analyzed us-ing XRD(X-ray diffractometer). SEM(scanning electron microscopy) and TEM(transmission electron mi-croscopy) TiO2 crystalline precipitate with rutile phases is fully formed at the temperatures of up to $65^{circ}C$ and then TiO2 crystalline precipitate with anatase phase starts to be formed above temperatures $65^{circ}C$ showing its full formation at 10$0^{circ}C$ These behaviors of TiO2 crystalline precipitate directly from an aqueous TiOCl2 solution would be caused due to the existence of {{{{ OMICRON ^2+ }} ions from distilled water which oxydize TiOCl2 to TiO2 not hydrolyzing it to Ti(OH)4 Here thermodynamically stable TiO2 rutile phase generally formed at higher temperature is practically precipitated at lower temperatures in this study This may be due to the precipitation by very slow reaction enough to make TiO2 particles allocated into stable rutile structure.

Key words: TiO2, Rutile, Anatase, Ultrafine powders, Precipitation