Oil-immersed transformer plays a significant role in power systems, whose insulation failure will threaten the stable operation of the system, thus the requirements for its operational stability are higher. In this paper, the Rh-doped MoTe₂ (Rh-MoTe₂) monolayer is proposed for the detection of several typically dissolved gas molecules (CO, H₂ and CH₄) based on the first-principles density functional theory (DFT). It is found that the Rh dopant preferred to be adsorbed through the T_Mo site with maximum binding energy (E_b) of −3.43 eV. Then, the adsorption of Rh-MoTe₂ on CO, H₂ and CH₄ molecules is investigated with adsorption energy (E_ad). Furthermore, the band gaps of CO and H₂ systems have significantly reduced, showing their excellent potential as resistance-type gas sensors; while CH₄ is not suitable for detection due to the weak interaction. This study illustrates the physicochemical properties of Rh-MoTe₂ monolayer and reveals its promising applications in dissolved gas analysis (DGA).

油浸式变压器在电力系统中占有举足轻重的地位，其绝缘失效会威胁到系统的稳定运行，对其运行稳定性提出了更高的要求。在本文中，基于第一性原理密度泛函理论 (DFT)，提出了 Rh 掺杂的 MoTe ₂ (Rh-MoTe ₂ ) 单分子层用于检测几种典型溶解气体分子（CO、H ₂和 CH _{4 ）。}结果发现，Rh 掺杂剂更倾向于通过 T _Mo位点吸附，最大结合能 ( E _b ) 为 -3.43 eV。_{然后，Rh-MoTe 2}对CO、H ₂和CH ₄的吸附用吸附能 ( E _ad )研究分子。_{此外，CO和H 2}体系的带隙明显减小，显示出作为电阻式气体传感器的卓越潜力；而CH ₄相互作用弱，不适合检测。本研究阐明了 Rh-MoTe ₂单分子层的物理化学性质，并揭示了其在溶解气体分析 (DGA) 中的前景广阔的应用。