Novel Mixed Phase SnO2 Nanorods Assembled with SnO2 Nanocrystals for Enhancing Gas-Sensing Performance toward Isopropanol Gas

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• 作者：Dan Hu ; Bingqian Han ; Shaojuan Deng ; Zhipeng Feng ; Yan Wang ; Jasminka Popovic ; Marko Nuskol ; Yude Wang ; Igor Djerdj
• 刊名：Journal of Physical Chemistry C
• 出版年：2014
• 出版时间：May 8, 2014
• 年：2014
• 卷：118
• 期：18
• 页码：9832-9840
• 全文大小：560K
• 年卷期：v.118,no.18(May 8, 2014)
• ISSN：1932-7455

文摘

The synthesis and the gas sensing properties of novel mixed phase (i.e., tetragonal and orthorhombic phase) coexistence SnO₂ nanorods are presented. The mixed phases SnO₂ nanorods were obtained by calcinations of SnC₂O₄ synthesized with a chemical precipitation method using SnCl₂路2H₂O and PEG 400 as precursors. The resulting nanorods appear as polycrystalline composed of spherical mixed phases SnO₂ nanocrystals and have a high surface area. It was observed that the calcination temperature was the key parameter determining the content of the orthorhombic phase. The as-synthesized compounds were used as sensing materials of the sensors of indirect heating structure and tested for their ability to detect volatile organic compounds (VOCs), such as isopropanol, acetone, alcohol, and formaldehyde. Gas sensing tests showed that these mixed phases SnO₂ nanorods are highly promising for gas sensor applications, as the gas response for isopropanol was significantly enhanced by the presence of orthorhombic phase (S = 61.5 at 1000 ppm isopropanol and response time and recovery time of 4 and 10 s). The as-prepared two phases SnO₂ nanorods with the highest content of the orthorhombic phase exhibit excellent gas response, selectivity, and stability toward isopropanol gas at the optimized operating temperature of 255 掳C. The enhancement in sensitivity is attributed to the presence of small orthorhombic SnO₂ crystals with average radius shorther than the Debye screening length of 7 nm for SnO₂.