Exposure to nitrogen oxides (NO_x) has been reported to seriously affect the respiratory systems. More precisely, breathing NO_x may lead to the appearance of asthma symptoms, and may also result in the infection with asthma over long intervals. This study is devoted to finding novel systems to detect nitric oxide (NO) and nitrogen dioxide (NO₂) with improved sensitivity. Consequently, gold (Au) and silver (Ag) codoped molybdenum disulfide (MoS₂) (Au–Ag–MoS₂) is proposed as NO and NO₂ gas sensor based on density functional theory (DFT) calculations. The variations of the electronic properties as well as the adsorption parameters of the new proposed sensor upon the adsorption of NO and NO₂ gases are compared with pristine, Au-doped, and Ag-doped MoS₂. The results reflect a remarkable change in the band gap of the developed systems upon the adsorption of NO and NO₂ gases. Meanwhile, the adsorption parameters demonstrate that the Au doped MoS₂ system is selective to NO, while the codoped MoS₂ system is selective to NO₂. Specifically, the Au-doped MoS₂ exhibits its maximum adsorption energy (E_ads) towards NO of −0.721 eV. Moreover, the highest adsorption energy and charge transfer ($\Delta$Q) are found to be −2.603 eV and 0.448 e, respectively, for the case of NO₂/Au–Ag-codoped MoS₂. Hence, our investigation suggests that Au–Ag-codoped MoS₂ can be utilized as a gas sensor for the detection of NO₂ gas.

暴露于氮氧化物（NO _X）已报道严重影响呼吸系统。更确切地说，呼吸NO _X可能导致哮喘症状的出现，也可能导致感染哮喘长的时间间隔。这项研究致力于发现新型系统，以提高灵敏度来检测一氧化氮（NO）和二氧化氮（NO ₂）。因此，有人建议将金（Au）和银（Ag）共掺杂的二硫化钼（MoS ₂）（Au–Ag–MoS ₂）作为NO和NO _2。气体传感器基于密度泛函理论（DFT）的计算。将新提出的传感器在吸附NO和NO ₂气体时的电子性能以及吸附参数的变化与原始，Au掺杂和Ag掺杂的MoS _{2进行了比较}。结果反映了在吸附NO和NO ₂气体后，已开发系统的带隙发生了显着变化。同时，吸附参数表明Au掺杂的MoS ₂系统对NO具有选择性，而共掺杂的MoS ₂系统对NO ₂具有选择性。具体来说，Au掺杂的MoS ₂表现出最大的吸附能（E _ads）达到-0.721 eV的NO。而且，最高的吸附能和电荷转移（$\Delta$对于NO ₂ / Au-Ag掺杂的MoS ₂，发现Q）分别为-2.603 eV和0.448 e 。因此，我们的研究表明，Au-Ag掺杂的MoS ₂可用作检测NO ₂气体的气体传感器。