School of Artificial Intelligence and Information Technology, Nanjing University of Chinese Medicine, No. 138 Xianling Rd, Nanjing, 210023, China.
School of Physics and Optoelectronic Engineering, Shenzhen University, Shenzhen, 518060, China.
Mikrochim Acta. 2023 Jul 6;190(8):283. doi: 10.1007/s00604-023-05843-7.
Transition metal dichalcogenides (TMDs) are promising materials for chemiresistive gas sensor, while TMD alloys (two chalcogenide or/and metal elements) with tunable electronic structures have drawn little attention in gas sensing. Herein, MoWS alloy nanoparticles (NPs) were prepared by a facile sonication exfoliation method and then tested for ammonia sensing. The crystal structure, geometric morphology, and elemental composition of MoWS NPs were investigated. The gas sensing measurements demonstrated MoWS NPs with good response to ammonia at 80 °C with a limit of detection down to 500 part per billion (ppb). The sensor also displayed good stability as well as superb selectivity to ammonia in the presence of interferences, such as methanol, acetone, benzene, and cyclohexane. The theoretical calculations revealed Mo and W atoms at edges (such as MoWS (010)) of sheet-like NPs as the active sites for ammonia adsorption. Electrons donated by the adsorbed ammonia were combined with holes in p-type MoWS NPs, and the concentration of the main charge carrier was reduced, resulting in resistance enhancement.
过渡金属二硫属化物 (TMDs) 是用于电阻式气体传感器的有前途的材料，而具有可调谐电子结构的 TMD 合金（两种硫属元素和/或金属元素）在气体传感方面的关注度较低。本文通过简便的超声剥离方法制备了 MoWS 合金纳米粒子 (NPs)，并对其氨气传感性能进行了测试。对 MoWS NPs 的晶体结构、几何形貌和元素组成进行了研究。气体传感测量表明，MoWS NPs 在 80°C 时对氨气具有良好的响应，检测限低至 500 皮克每十亿（ppb）。该传感器在存在甲醇、丙酮、苯和环己烷等干扰物的情况下，对氨气也表现出良好的稳定性和超高的选择性。理论计算表明，片状 NPs 边缘（如 MoWS(010)）处的 Mo 和 W 原子是氨吸附的活性位点。吸附氨提供的电子与 p 型 MoWS NPs 中的空穴结合，主电荷载流子的浓度降低，导致电阻增强。
