Two-dimensional (2D) materials are considered as ideal building blocks for constructing new functional gas-sensitive devices because of their large specific surface area, abundant active sites and high carrier mobility. However, research has mainly focused on 2D layered materials due to their easy availability. This work aims to further explore the application value of 2D non-layered materials in gas sensing. Firstly, van der Waals epitaxial growth of 2D non-layered CdS1-xSex on fluorophlogopite substrate was achieved by APCVD. Secondly, the CdS1-xSex-based gas sensor exhibits high sensitivity (626 % at 50 ppm NH3), low detection limit (1 ppm), fast response (12 s at 50 ppm NH3), good selectivity and repeatability to NH3 at room temperature. Notably, the sensing performance of the ternary CdS1-xSex for NH3 is better than other structures of binary CdS. This phenomenon is also further explained. Finally, density functional theory is used to calculate the adsorption energy and charge transfer properties, and the results reconfirm that CdS1-xSex is a promising NH3 sensing material. This work provides a universal synthesis method of 2D non-layered alloy materials, and explores the application of 2D CdS1-xSex in gas sensing for the first time, hoping to bring new ideas for the research of other 2D non-layered materials.

中文翻译：

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用于高灵敏度 [公式省略] 检测的二维非分层 [公式省略] 的范德华外延生长


二维 （2D） 材料因其大比表面积、丰富的活性位点和高载流子迁移率而被认为是构建新型功能性气体敏感器件的理想构建块。然而，由于 2D 层状材料很容易获得，因此研究主要集中在 2D 层状材料上。本工作旨在进一步探索二维非层状材料在气体传感中的应用价值。首先，通过 APCVD 实现了 2D 非层状 CdS1-xSex 在荧光金云母衬底上的范德华外延生长。其次，基于 CdS1-xSex 的气体传感器具有高灵敏度（50 ppm NH3 时为 626 %）、低检出限 （1 ppm）、快速响应（50 ppm NH3 时为 12 秒）、良好的选择性和室温下对 NH3 的可重复性。值得注意的是，三元 CdS1-xSex 对 NH3 的传感性能优于二元 CdS 的其他结构。这种现象也得到了进一步的解释。最后，采用密度泛函理论计算吸附能和电荷转移特性，结果再次证实 CdS1-xSex 是一种很有前途的 NH3 传感材料。本工作提供了一种二维非层状合金材料的通用合成方法，并首次探索了二维 CdS1-xSex 在气传感中的应用，希望为其他二维非层状材料的研究带来新思路。