Department of Inorganic and Physical Chemistry , Indian Institute of Science , Bangalore 560012 , India.
ACS Sens. 2020 Feb 28;5(2):404-411. doi: 10.1021/acssensors.9b02064. Epub 2020 Feb 7.
In this study, two-dimensional few-layer MnPS is introduced as a selective and reversible NO gas sensor in dry nitrogen (N) under ambient conditions. The solvent exfoliation technique is utilized to exfoliate bulk MnPS into a few layers, which are further assembled as thin films by the vacuum filtration method. The films are subsequently transferred onto a sensing device and used for NO sensing. Exfoliated MnPS shows excellent sensitivity toward NO gas with a low detection limit of a few tens of ppb at 25 °C. A sensitivity of 9530% is obtained at 35 ppm concentration of NO with the theoretical limit of detection calculated to be ∼9.5 ppb. The sensor is highly selective toward NO gas (with respect to interferents NO, NH, H, CO, CO, CH, and O) and is fully reversible under ambient conditions. The time constant is determined to be in the range of 30-160 s for adsorption and desorption processes. Raman spectroscopy reveals that the mechanism of sensing is based on charge transfer interactions between the sensor and analyte. This study opens up ways to fabricate gas sensors using few-layer metal phosphochalcogenides (MPX).
在这项研究中，二维少层 MnPS 被引入作为一种在环境条件下的干燥氮气（N）中选择性和可逆的 NO 气体传感器。利用溶剂剥离技术将块状 MnPS 剥离成少层，然后通过真空过滤法将其进一步组装成薄膜。将薄膜转移到传感设备上用于 NO 传感。剥离的 MnPS 对 NO 气体表现出优异的灵敏度，在 25°C 时检测下限低至几十 ppb。在 35 ppm 的 NO 浓度下，获得了 9530%的灵敏度，理论检测限计算为约 9.5 ppb。该传感器对 NO 气体（相对于干扰物 NO、NH、H、CO、CO、CH 和 O）具有高度选择性，在环境条件下完全可逆。吸附和解吸过程的时间常数确定在 30-160 s 范围内。拉曼光谱表明，传感的机制基于传感器和分析物之间的电荷转移相互作用。这项研究为使用少层金属磷硫属化物（MPX）制造气体传感器开辟了道路。
