This paper describes the theory and results for a new class of low-cost chemoresistive gas sensors designed for selective hydrocarbon gas detection. The sensors utilize a multiwalled carbon nanotube (MWCNT) backbone functionalized with metal oxide nanocrystals. Specifically, nanoparticles were grown on the surface of the MWCNTs using atomic layer deposition. The crystallinity of the ZnO-MWCNTs’ heterostructure was examined by using a high-resolution transmission electron microscope. The structure of the ZnO/MWCNTs was analyzed using a scanning electron microscope and energy dispersive x ray. The Hall effect measurement shows p-type characteristics of the MWCNTs, supporting the typical PN junction formation with n-type ZnO nanocrystals. The electron-donating ability of ZnO provided a strong response to the ppm levels of toluene at room temperature (25 °C) and showed strong selectivity with other volatile organic compound gases such as benzene, methane, and formaldehyde.

中文翻译：

---

基于氧化锌纳米颗粒功能化碳纳米管的选择性挥发性有机化合物气体传感器

本文介绍了一类用于选择性烃类气体检测的新型低成本化学电阻式气体传感器的理论和结果。这些传感器利用了金属氧化物纳米晶体功能化的多壁碳纳米管 (MWCNT) 骨架。具体而言，纳米粒子使用原子层沉积在 MWCNT 的表面上生长。通过使用高分辨率透射电子显微镜检查了 ZnO-MWCNTs 异质结构的结晶度。使用扫描电子显微镜和能量色散 X 射线分析 ZnO/MWCNTs 的结构。霍尔效应测量显示 MWCNT 的 p 型特性，支持典型的 PN 结形成与 n 型 ZnO 纳米晶体。