Fabrication of three-dimensional network of ZnO tetratpods and its response to ethanol
Fabrication of three-dimensional network of ZnO tetratpods and its response to ethanol
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DOI：
10.1016/j.matchemphys.2007.02.099
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发表时间：
2007-07
影响因子：
4.6
通讯作者：
J. Delaunay;Naoki Kakoiyama;I. Yamada
中科院分区：
文献类型：
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作者：
J. Delaunay;Naoki Kakoiyama;I. Yamada
在石英衬底上制备了ZnO四脚体三维网络结构。通过简单的热氧化反应合成了具有数μm长、直径在0.1-1μm范围内的相互连接的四足体。将Zn粉末在炉中在900°C的温度下加热，并使其与空气和水蒸气反应。发现空气中的水蒸气含量控制到衬底上的粘附性和沉积层的形态。根据空气中的水蒸气含量，这些层形成了由相互连接的四足动物组成的颗粒结构或多孔结构。对于小含量的水蒸气获得的四脚体的网络形成具有高表面与体积比的高度多孔层。通过测量暴露于乙醇时其电阻的变化，将四足体网络作为气敏元件进行测试。乙醇的响应作为层温度和乙醇浓度的函数进行了研究。发现四足体网络层的最佳温度为400°C，在该温度下，乙醇浓度低至0.5ppm就容易被检测到。的四脚网络表现出10倍的灵敏度增加时，与ZnO多晶厚膜相比。
A three-dimensional network of ZnO tetrapods was fabricated on a quartz substrate. The interconnected tetrapods, having legs with length of several μm and diameter in the 0.1–1μm range, were synthesized via a simple thermal oxidation reaction. Zn powder was heated in a furnace at a temperature of 900°C and was made to react with air and water vapor. The content of water vapor in air was found to control the adherence onto the substrate and the morphology of the deposited layers. The layers developed a grain structure or a porous structure made of interconnected tetrapods, depending on the content of water vapor in air. The network of tetrapods which was obtained for a small content of water vapor formed a highly porous layer with a high surface to volume ratio. The tetrapod network was tested as a gas sensing element by measuring changes in its electrical resistance upon exposure to ethanol. The responses to ethanol were investigated as a function of the layer temperature and the ethanol concentration. The optimum temperature of the tetrapod network layer was found to be 400°C, at which ethanol concentration as low as 0.5ppm was easily detected. The tetrapod network exhibited a 10-fold increase in sensitivity when compared with a ZnO polycrystalline thick film.