Crystallization behaviour of TiO2–ZrO2 composite nanoparticles
Crystallization behaviour of TiO2–ZrO2 composite nanoparticles
复制标题
TiO2-ZrO2复合纳米粒子的结晶行为
DOI：
10.1007/s10971-012-2824-5
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发表时间：
2012
影响因子：
2.5
通讯作者：
R. Frahm
中科院分区：
文献类型：
--
作者：
S. Pfleiderer;D. Lützenkirchen;R. Frahm
将TiO2:ZrO2比例分别为1:2、1:1、2:1和10:1的含钛和含锆烷氧化物混合物通过溶胶-凝胶法水解制备纳米复合TiO2 - ZrO2材料。将沉淀的粉末在室温下干燥，在350 ~ 500℃的环境空气中退火4 h，合成纯TiO2和ZrO2粉末进行比较。采用x射线衍射（XRD）和x射线吸收近边缘精细结构（XANES）对样品进行了表征。对这些数据的详细分析提供了晶体和非晶相组成以及晶体粒度。XRD和XANES分析表明，只有两种纯氧化物样品和一种TiO2:ZrO2 = 10:1的复合样品结晶。纯TiO2和TiO2:ZrO2 = 10:1复合TiO2均以锐钛矿结构结晶。ZrO2在复合材料中呈非晶态，而在纯氧化物中呈结晶态。在复合TiO2:ZrO2 = 10:1的结晶样品中，非晶相的浓度仍然大于纯TiO2样品，但与纯TiO2样品相比，随着退火温度的升高，晶粒尺寸几乎不变。纯TiO2析出物制备后直接呈无定形，在常温条件下贮存6个月后时效结晶。TiO2:ZrO2复合材料没有观察到这种老化现象。
Nano-composite TiO2–ZrO2 materials were prepared via sol–gel processes by hydrolysis of mixtures of titanium- and zirconium-containing alkoxides with TiO2:ZrO2 ratios of 1:2, 1:1, 2:1, and 10:1. Precipitated powders were dried at room temperature and annealed in ambient air at temperatures between 350 and 500 °C for 4 h. Pure TiO2 and ZrO2 powders were synthesized for comparison. Samples were characterized with X-ray diffraction (XRD) and X-ray absorption near edge fine structure (XANES). The detailed analysis of those data provides the crystalline and amorphous phase composition as well as the crystallite particle size. According to XRD and XANES analysis, only the two pure oxide samples and one of the composite samples with a composition TiO2:ZrO2 = 10:1, crystallized. Both titania containing powders, the pure TiO2 and the TiO2:ZrO2 = 10:1 composite, were found to crystallize in the anatase structure. ZrO2 was found to stay amorphous in the composites but crystalline in the pure oxide. In the crystallized composite TiO2:ZrO2 = 10:1 sample, the concentration of the amorphous phase remains larger than in pure TiO2 samples, but the crystallite size was found to be nearly constant with increasing annealing temperature in contrast to the increasing particle size of pure TiO2-samples. Pure TiO2 precipitates are amorphous directly after preparation, however they crystallize after 6 month storage at ambient conditions by aging. Such an aging was not observed for the TiO2:ZrO2 composites.
影响因子：
3.7
作者：
Farges, F;Brown, GE;Rehr, JJ
通讯作者：
Rehr, JJ