Department of Chemical and Biomolecular Engineering (BK-21 Plus) , Korea Advanced Institute of Science and Technology (KAIST) , Daejeon 34141 , Korea.
KAIST Institute for Nanocentury , Daejeon 34141 , Korea.
ACS Sens. 2018 Jul 27;3(7):1329-1337. doi: 10.1021/acssensors.8b00247. Epub 2018 Jul 10.
Strong acidic gases such as CO, SO, and NO are harsh air pollutants with major human health threatening factors, and as such, developing new tools to monitor and to quickly sense these gases is critically required. However, it is difficult to selectively detect the acidic air pollutants with single channel material due to the similar chemistry shared by acidic molecules. In this work, three acidic gases (i.e., CO, SO, and NO) are selectively discriminated using single channel material with precise moiety design. By changing the composition ratio of primary (1°), secondary (2°), and tertiary (3°) amines of polyethylenimine (PEI) on CNT channels, unprecedented high selectivity between CO and SO is achieved. Using in situ FT-IR characterizations, the distinct adsorption phenomenon of acidic gases on each amine moiety is precisely demonstrated. Our approach is the first attempt at controlling gas adsorption selectivity of solid-state sensor via modulating chemical moiety level within the single channel material. In addition, discrimination of CO, SO, and NO with the single channel material solid-state sensor is first reported. We believe that this approach can greatly enhance air pollution tracking systems for strong acidic pollutants and thus aid future studies on selective solid-state gas sensors.
强酸性气体如 CO、SO 和 NO 是具有主要人类健康威胁因素的恶劣空气污染物，因此，开发新的工具来监测和快速感知这些气体是至关重要的。然而，由于酸性分子具有相似的化学性质，因此很难使用单通道材料选择性地检测酸性空气污染物。在这项工作中，使用精确的部分设计的单通道材料选择性地区分了三种酸性气体（即 CO、SO 和 NO）。通过改变碳纳米管通道上聚乙烯亚胺（PEI）的一级（1°）、二级（2°）和三级（3°）胺的组成比例，在 CO 和 SO 之间实现了前所未有的高选择性。通过原位 FT-IR 特性分析，精确地证明了酸性气体在每个胺部分上的独特吸附现象。我们的方法是首次尝试通过调节单通道材料内的化学部分水平来控制固态传感器的气体吸附选择性。此外，还首次报道了使用单通道材料固态传感器对 CO、SO 和 NO 的区分。我们相信，这种方法可以极大地增强对强酸性污染物的空气污染跟踪系统，从而有助于未来对选择性固态气体传感器的研究。
