Self-assembly of [10(1)over-bar0] grown ZnO nanowhiskers with exposed reactive (0001) facets on hollow spheres and their enhanced gas sensitivity
Self-assembly of [10(1)over-bar0] grown ZnO nanowhiskers with exposed reactive (0001) facets on hollow spheres and their enhanced gas sensitivity
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DOI：
10.1039/c0ce00821d
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发表时间：
2011-05-01
期刊：
影响因子：
3.1
通讯作者：
Guo, Zaiping
中科院分区：
文献类型：
--
作者：
Liu, Jun;Chen, Xiaolong;Guo, Zaiping
在这项工作中，我们展示了一种简单的气相工艺，可以在不使用任何封端剂的情况下合成具有暴露的反应性{0001}面的ZnO。该方法基于控制 ZnO 生长方向，使其从典型的 [0001] 切换到 [10 (1) over bar0]，从而产生 [10 (1) over bar0] 生长的纳米晶须，并具有暴露的反应性 {0001} 面。此外，这些纳米晶须在 ZnO 空心球上自组装，形成三维分层纳米结构，从而稳定这些纳米晶须，防止团聚。这种设计的ZnO纳米结构赋予ZnO传感材料小晶体尺寸和暴露的反应性{0001}面，与典型的[0001]生长的ZnO纳米线相比，这导致气体灵敏度大大增强。我们基于密度泛函理论对氧气化学吸附能的计算也显示了这种反应面增强的气体敏感性。
In this work, we demonstrate a simple gas-phase process to synthesize ZnO with exposed reactive {0001} facets without the use of any capping agent. The method is based on controlling the ZnO growth direction, causing it to switch from the typical [0001] to [10 (1) over bar0], resulting in [10 (1) over bar0] grown nanowhiskers with exposed reactive {0001} facets. Moreover, these nanowhiskers self-assemble on ZnO hollow spheres to form a three-dimensional hierarchical nanostructure, which stabilizes these nanowhiskers against agglomeration. Such a designed ZnO nanostructure endows the ZnO sensing material with both small crystal sizes and exposed reactive {0001} facets, which leads to greatly enhanced gas sensitivities compared to typical [0001] grown ZnO nanowires. Such reactive-facet-enhanced gas sensitivity is also shown by our calculation of the chemisorption energy of oxygen, based on density functional theory.