Nanoparticle cluster gas sensor: controlled clustering of SnO₂ nanoparticles for highly sensitive toluene detection.
Nanoparticle cluster gas sensor: controlled clustering of SnO₂ nanoparticles for highly sensitive toluene detection.
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DOI：
10.1021/am500944a
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发表时间：
2014-03
影响因子：
9.5
通讯作者：
K. Suematsu;Yuka Shin;Z. Hua;Kohei Yoshida;M. Yuasa;T. Kida;K. Shimanoe
中科院分区：
文献类型：
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作者：
K. Suematsu;Yuka Shin;Z. Hua;Kohei Yoshida;M. Yuasa;T. Kida;K. Shimanoe
纳米氧化物气敏材料由于其在检测各种低浓度有毒气体方面的潜力而备受关注。在这项研究中，使用聚集的SnO2纳米粒子形成的控制颗粒聚集，我们制作了高灵敏度的气体传感膜检测大的气体分子，如甲苯。以锡酸（SnO2·nH2O）凝胶为前驱体，采用水热法制备了单分散的SnO2纳米粒子。5 nm，pH 10.6。将溶液pH降低至9.3形成Ca. 45 nm的单分散纳米颗粒的组装，如通过动态光散射，X射线衍射，和透射电子显微镜分析确定的。利用团聚纳米颗粒的松散堆积特性，采用旋涂法成功制备了多孔气敏薄膜。使用多孔膜的传感器装置在300 °C下显示出对H2和CO的改进的传感器响应（灵敏度）。提高灵敏度是由于薄膜的孔隙率增加，从而促进了敏感膜的气体扩散。由于Pd的催化和电敏化作用，负载到簇状纳米颗粒上的Pd进一步升级了传感器响应。特别是，负载Pd的SnO2纳米颗粒簇对甲苯表现出优异的灵敏度，能够在低至ppb的水平下检测到甲苯。
Gas sensing with nanosized oxide materials is attracting much attention because of its promising capability of detecting various toxic gases at very low concentrations. In this study, using clustered SnO2 nanoparticles formed by controlled particle aggregation, we fabricated highly sensitive gas sensing films to detect large gas molecules such as toluene. A hydrothermal method using stanic acid (SnO2·nH2O) gel as a precursor produced monodispersed SnO2 nanoparticles of ca. 5 nm at pH 10.6. Decreasing the solution pH to 9.3 formed SnO2 clusters of ca. 45 nm that were assemblies of the monodispersed nanoparticles, as determined by dynamic light scattering, X-ray diffraction, and transmission electron microscopy analyses. Porous gas sensing films were successfully fabricated by a spin-coating method using the clustered nanoparticles due to the loose packing of the larger aggregated particles. The sensor devices using the porous films showed improved sensor responses (sensitivities) to H2 and CO at 300 °C. The enhanced sensitivity resulted from an increase in the film's porosity, which promoted the gas diffusivity of the sensing films. Pd loading onto the clustered nanoparticles further upgraded the sensor response due to catalytic and electrical sensitization effects of Pd. In particular, the Pd-loaded SnO2 nanoparticle clusters showed excellent sensitivity to toluene, able to detect it at down to low ppb levels.