Zhou Jin, Bagheri Mohammad, Järvinen Topias, Pravda Bartus Cora, Kukovecz Akos, Komsa Hannu-Pekka, Kordas Krisztian
Country Microelectronics Research Unit, Faculty of Information Technology and Electrical Engineering, University of Oulu, P.O. Box 4500, FIN-90014 Oulu, Finland.
Interdisciplinary Excellence Centre, Department of Applied and Environmental Chemistry, University of Szeged, Rerrich Bélatér 1, H-6720 Szeged, Hungary.
ACS Appl Mater Interfaces. 2021 Dec 15;13(49):59067-59075. doi: 10.1021/acsami.1c16807. Epub 2021 Dec 6.
HS is a toxic and corrosive gas, whose accurate detection at sub-ppm concentrations is of high practical importance in environmental, industrial, and health safety applications. Herein, we propose a chemiresistive sensor device that applies a composite of single-walled carbon nanotubes (SWCNTs) and brominated fullerene (CBr) as a sensing component, which is capable of detecting 50 ppb HS even at room temperature with an excellent response of 1.75% in a selective manner. In contrast, a poor gas response of pristine C-based composites was found in control measurements. The experimental results are complemented by density functional theory calculations showing that CBr in contact with SWCNTs induces localized hole doping in the nanotubes, which is increased further when HS adsorbs on CBr but decreases in the regions, where direct adsorption of HS on the nanotubes takes place due to electron doping from the analyte. Accordingly, the heterogeneous chemical environment in the composite results in spatial fluctuations of hole density upon gas adsorption, hence influencing carrier transport and thus giving rise to chemiresistive sensing.
硫化氢是一种有毒且具有腐蚀性的气体，在环境、工业和健康安全应用中，在亚ppm浓度下对其进行准确检测具有很高的实际重要性。在此，我们提出一种化学电阻式传感器装置，该装置采用单壁碳纳米管（SWCNTs）和溴化富勒烯（CBr）的复合材料作为传感组件，即使在室温下也能够以1.75%的优异响应选择性地检测50 ppb的硫化氢。相比之下，在对照测量中发现原始碳基复合材料的气体响应较差。密度泛函理论计算对实验结果进行了补充，结果表明与单壁碳纳米管接触的溴化富勒烯会在纳米管中引起局部空穴掺杂，当硫化氢吸附在溴化富勒烯上时，这种掺杂会进一步增加，但在由于分析物的电子掺杂导致硫化氢直接吸附在纳米管上的区域，掺杂会减少。因此，复合材料中的异质化学环境会导致气体吸附时空穴密度的空间波动，从而影响载流子传输，进而产生化学电阻传感。
