Low temperature nanostructured zinc titanate by an aqueous particulate sol–gel route: Optimisation of heat treatment condition based on Zn:Ti molar ratio
Low temperature nanostructured zinc titanate by an aqueous particulate sol–gel route: Optimisation of heat treatment condition based on Zn:Ti molar ratio
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DOI：
10.1016/j.jeurceramsoc.2009.09.031
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发表时间：
2010-03
影响因子：
5.7
通讯作者：
M. Mohammadi;D. Fray
中科院分区：
文献类型：
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作者：
M. Mohammadi;D. Fray
采用溶胶-凝胶法，在500°C的低温烧结条件下，在1h的短时间内制备了纯度为94%的纳米钛酸锌（ZnTiO 3）薄膜和粉体。研究了Zn：Ti摩尔比对钛酸锌结晶行为的影响。所制备的溶胶显示出在17- 19 nm范围内的窄粒度分布。X射线衍射（XRD）和傅里叶变换红外光谱（FTIR）分析表明，随烧结温度和Zn：Ti摩尔比的变化，粉体中含有菱面体-ZnTiO 3、锐钛矿-ZnO、锐钛矿-Zn 2 TiO 4以及锐钛矿-TiO 2和金红石-TiO 2的混合物。Zn：Ti摩尔比和烧结温度影响钛酸锌的择优取向生长，当Zn：Ti摩尔比为25：75和50：50时，钛酸锌的择优取向生长在（211）晶面;当Zn：Ti摩尔比为75：25时，在600°C烧结时，钛酸锌的择优取向生长在（11 <$0）晶面。透射电子显微镜（TEM）结果表明，400°C热处理后的粉体平均晶粒尺寸约为2nm，1000°C热处理后晶粒尺寸逐渐增大，最大可达8 nm。计算出纳米晶ZnTiO_3晶体生长的激活能为07.86-14.79kJ/mol。场发射扫描电子显微镜（FE-SEM）分析表明，沉积的薄膜具有介孔和纳米晶结构，在600°C下的平均晶粒尺寸为19- 23 nm，在800°C下的平均晶粒尺寸为34- 39 nm，这取决于Zn：Ti摩尔比。
Nanocrystalline zinc titanate (ZnTiO3) thin films and powders with purity of 94% were produced at the low sintering temperature of 500°C and the short sintering time of 1h by a straightforward aqueous particulate sol–gel route. The effect of Zn:Ti molar ratio was studied on the crystallisation behaviour of zinc titanates. The prepared sols showed a narrow particle size distribution in the range 17–19nm. X-ray diffraction (XRD) and Fourier transform infrared spectroscopy (FTIR) revealed that the powders contained mixtures of the rhombohedral-ZnTiO3, cubic-ZnO, cubic-Zn2TiO4phases, as well as the anatase-TiO2and the rutile-TiO2depending on the sintering temperature and Zn:Ti molar ratio. Moreover, it was found that Zn:Ti molar ratio and sintering temperature influence the preferable orientation growth of the zinc titanate, being on (211) planes for molar ratios of Zn:Ti=25:75 and 50:50 and on (11¯0) planes for molar ratio of Zn:Ti=75:25 at sintering temperature of 600°C. Transmission electron microscope (TEM) images showed that the average crystallite size of the powders annealed at 400°C was around 2nm and a gradual increase occurred up to 8nm by heat treatment at 1000°C. The activation energy for crystal growth of nanocrystalline ZnTiO3calculated in the range 07.86–14.79kJ/mol. Field emission scanning electron microscope (FE-SEM) analysis revealed that the deposited thin films had mesoporous and nanocrystalline structure with the average grain size of 19–23nm at 600°C and 34–39nm at 800°C depending upon the Zn:Ti molar ratio.