Abstract The multiwalled carbon nanotubes were successfully electrophoresis deposited onto porous silicon to form a multiwalled carbon nanotubes/porous silicon composite and were then fabricated into chemiresistive gas sensors. The morphology, microstructure and NO2-sensing characteristics of the composite were investigated by scanning electron microscopy, X-ray diffraction, X-ray photoelectron spectroscopy, Raman spectroscopy and gas-sensing test. The results indicated that all the carbon nanotubes/porous silicon sensors showed typical p-type semiconductor behavior at room temperature (∼25°C) of the optimal working temperature. The carbon nanotubes/porous silicon sensor under the electrophoresis time of 5 min yielded the best NO2-sensing characteristics, including a high sensor response (∼8.5), fast response-recovery time (∼37 s and ∼34 s), good repeatability and selectivity toward 1 ppm NO2. The heterostructure effect as well as the high specific surface area and the unblocked porous structure was considered essential for the gas-sensing performance.

中文翻译：

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多壁碳纳米管在多孔硅上的电泳沉积，具有增强的 NO2 传感特性

摘要 将多壁碳纳米管成功地电泳沉积到多孔硅上，形成多壁碳纳米管/多孔硅复合材料，然后制成化学电阻式气体传感器。通过扫描电子显微镜、X射线衍射、X射线光电子能谱、拉曼光谱和气敏测试研究了复合材料的形貌、微观结构和NO2传感特性。结果表明，所有碳纳米管/多孔硅传感器在最佳工作温度的室温（~25°C）下均表现出典型的 p 型半导体行为。碳纳米管/多孔硅传感器在 5 分钟的电泳时间下产生了最佳的 NO2 传感特性，包括高传感器响应（~8.5）、快速响应恢复时间（~37 秒和~34 秒），对 1 ppm NO2 具有良好的重复性和选择性。异质结构效应以及高比表面积和未堵塞的多孔结构被认为对气敏性能至关重要。