Synthesis of Nanograined ZnO Nanowires and Their Enhanced Gas Sensing Properties

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• 作者：Sunghoon Park ; Soyeon An ; Hyunsung Ko ; Changhyun Jin ; Chongmu Lee
• 刊名：ACS Applied Materials & Interfaces
• 出版年：2012
• 出版时间：July 25, 2012
• 年：2012
• 卷：4
• 期：7
• 页码：3650-3656
• 全文大小：414K
• 年卷期：v.4,no.7(July 25, 2012)
• ISSN：1944-8252

文摘

Polycrystalline ZnO nanowires with grain sizes ranging from 20 to 100 nm were synthesized using a newly designed two-step process: (first step) synthesis of ZnSe nanowires by vapor transportation of a mixture of ZnSe powders; and (second step) thermal oxidation of the ZnSe nanowires at 650 掳C. Compared to the single-crystal ZnO nanowire gas sensors and other nanomaterial gas sensors reported previously, the multiple networked nanowire gas sensors fabricated from the nanograined ZnO nanowires showed substantially enhanced electrical responses to NO₂ gas at 300 掳C. The NO₂ gas sensing properties of the nanograined ZnO nanowires increased dramatically with increasing NO₂ concentration. The multiple-networked nanograined ZnO nanowire sensor showed a response value of 237,263% at 10 ppm NO₂ and 300 掳C, whereas the single-crystal ZnO nanowire sensors showed a response of only 6.5% under the same conditions. The recovery time of the nanograined ZnO nanowire sensor was much shorter than that of the normal ZnO nanowire sensor over the NO₂ concentration range of 1鈥?0 ppm, even though the response time of the former was somewhat longer than that of the latter. The origin of the enhanced NO₂ gas sensing properties of the nanograined ZnO nanowire sensor is discussed.

Keywords:

nanowires; ZnO; polycrystalline; Gas sensor; NO₂