Catalyst-free synthesis of single crystalline ZnO nanonails with ultra-thin caps
Catalyst-free synthesis of single crystalline ZnO nanonails with ultra-thin caps
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无催化剂合成超薄帽单晶 ZnO 纳米钉
DOI：
10.1039/c2ce26197a
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发表时间：
2012-01-01
期刊：
影响因子：
3.1
通讯作者：
Meng, Xiang-Min
中科院分区：
文献类型：
--
作者：
Huang, Xing;Shao, Lidong;Meng, Xiang-Min
通过简单的无催化剂热蒸发方法在硅衬底上成功地合成了具有锥形直径和超薄帽的单晶ZnO纳米钉阵列。每个ZnO纳米钉由底部的纳米线（茎）和顶部的超薄对称六边形帽组成。结构表征表明，所合成的ZnO纳米钉具有纤锌矿（WZ）结构，在茎部和帽部具有[0001]的择优生长方向。值得注意的是，超薄帽的直径与厚度之比超过20：1，这比以前的工作中报道的震级要高得多。基于系统的形貌表征和结构分析，提出了一个自催化的气-液-固（VLS）机制，其次是气-固（VS）过程来解释纳米钉的生长。利用拉曼和光致发光（PL）技术研究了纳米钉的光学性质，结果表明纳米钉具有良好的晶体质量。
Arrays of single-crystalline ZnO nanonails with tapering diameters and ultra-thin caps have been successfully synthesized on a silicon substrate via a simple catalyst-free thermal evaporation method. Each of the ZnO nanonails consists a nanowire (stem) on the bottom and an ultra-thin symmetrical hexagonal cap on the top. Structural characterization reveals that the synthesized ZnO nanonail has a wurtzite (WZ) structure with a preferred growth direction of [0001] in the stem and in the cap. Remarkably, the ultra-thin cap shows a diameter-to-thickness ratio of over 20:1, which is much higher in magnitude than those reported in previous works. Based on the systematic morphological characterization and structural analysis, a self-catalyzed vapor–liquid–solid (VLS) mechanism followed by a vapor–solid (VS) process is proposed to explain the growth of the nanonails. Optical properties are also investigated with Raman and photoluminescence (PL) techniques, which show good crystal quality of the synthesized nanonails.