Co3O4 nanostructures with different morphologies and their field-emission properties
Co3O4 nanostructures with different morphologies and their field-emission properties
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DOI：
10.1002/adfm.200700038
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发表时间：
2007-08-13
影响因子：
19
通讯作者：
Sow, Chorng-Haur
中科院分区：
文献类型：
--
作者：
Varghese, Binni;Hoong, Teo Choon;Sow, Chorng-Haur
我们报道了一种在钴箔表面合成垂直排列的四氧化三钴纳米结构的有效方法。这种合成是通过在氧气存在的情况下简单地加热钴箔来实现的。通过控制生长过程中氧物种的反应性和扩散速率，纳米结构的最终形态可以被调整为一维纳米线或二维纳米壁。我们讨论了一种可能的控制此类纳米结构形成的生长机制。详细研究了所合成纳米结构的场发射特性。纳米线和纳米壁的开启电场分别确定为6.4和7.7 V/μm。由于纳米线样品具有尖锐的尖端几何形状和高的长径比，它们表现出更优异的场发射特性，具有更低的开启电场和更高的电流密度。
We report an efficient method to synthesize vertically aligned Co3O4 nanostructures on the surface of cobalt foils. This synthesis is accomplished by simply heating the cobalt foils in the presence of oxygen gas. The resultant morphologies of the nanostructures can be tailored to be either one-dimensional nanowires or two-dimensional nanowalls by controlling the reactivity and the diffusion rate of the oxygen species during the growth process. A possible growth mechanism governing the formation of such nanostructures is discussed. The field-emission properties of the as-synthesized nanostructures are investigated in detail. The turn-on field was determined to be 6.4 and 7.7 V mu m(-1) for nanowires and nanowalls, respectively. The nanowire samples show superior field-emission characteristics with a lower turn-on field and higher current density because of their sharp tip geometry and high aspect ratio.