Adsorption and sensing of dissolved gas molecules in transformer oil on Rh-doped MoTe2 monolayer: A first-principles study

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 TMo site with maximum binding energy (Eb) of-3.43 eV. Then, the adsorption of Rh-MoTe2 on CO, H2 and CH4 molecules is investigated with adsorption energy (Ead). 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).