Direct observation of the growth process of MgO nanoflowers by a simple chemical route
Direct observation of the growth process of MgO nanoflowers by a simple chemical route
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DOI：
10.1002/smll.200400087
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发表时间：
2005-04-01
期刊：
影响因子：
13.3
通讯作者：
Yan, P
中科院分区：
文献类型：
--
作者：
Fang, XS;Ye, CH;Yan, P
通过简单的化学方法，在950 ℃的氩气气氛中，用H2O成功地合成了由MgO纳米纤维组成的新型花状纳米结构。不同的加热持续时间给出了不同的生长阶段，导致不同的产品形态。通过X射线粉末衍射、扫描电子显微镜、高分辨透射电子显微镜和能量色散X射线分析对合成产物进行了系统的研究。结果表明，MgO纳米花的成核和生长过程属于气-固机制，反应过程中的总加热时间是影响MgO纳米花生长的关键因素。首先在Si衬底上形成Mg颗粒，然后在镁熔体表面形成MgO团簇作为形核中心，并形成短的MgO纳米纤维，然后MgO纳米纤维生长，最后形成MgO纳米花。除了纳米花，还观察到新的分级MgO纳米结构。这些纳米结构可用作三维复合材料和用作其它材料的载体。
Novel flowerlike nanostructures consisting of MgO nanofibers were successfully synthesized by a simple chemical route with H2O at 950 degrees C in an Ar atmosphere. Various durations of heating gave different growth stages that led to varied product morphologies. The synthesized products were systematically studied by X-ray powder diffraction, scanning electron microscopy, high-resolution transmission electron microscopy, and energy-dispersive X-ray analysis. The results show that the nucleation and growth process of the nanoflowers seems to be a vapor-solid mechanism, and that the total heating time during the reaction process is a critical factor for the development of MgO nanoflowers. Initially, Mg particles formed on the Si substrate, followed by the formation of MgO clusters as nucleation centers on the magnesium melt surface and the nucleation of short MgO nanofibers, then growth of the MgO nanofibers occurred, and finally MgO nanoflowers were formed. Besides nanoflowers, novel hierarchical MgO nanostructures were also observed. These nanostructures may be used as three-dimensional composite materials and as supports for other materials.