Adsorption behavior of Rh-VSe2 monolayer upon dissolved gases in transformer oil and the effect of applied electric field

Dissolved gas analysis (DGA) in transformer oil is an effective method to monitor the operating status of transformers. Based on fundamental principles, the adsorption behavior of decomposed gases from transformer oil (CO, CH₄, C₂H₂, C₂H₄, and C₂H₆) on intrinsic and Rh-doped VSe₂ monolayers is examined. The adsorption structure, adsorption energy, charge transfer, density of state, electron density difference, work function, and desorption properties are discussed to evaluate the potential applications of VSe₂ monolayers as scavengers and gas-sensing materials for transformer oil decomposed gases. The results show that Rh dopant can be stably adsorbed on the surface of VSe₂ monolayer, and the minimum binding energy is −4.957 eV. The adsorption behavior of oil-dissolved gases on the intrinsic VSe₂ monolayer is weak. The sensing performance of VSe₂ monolayer for oil-dissolved gas molecules is significantly enhanced after the introduction of Rh dopant. The sensing performance of Rh-VSe₂ monolayer for CO, C₂H₂, C₂H₄ and C₂H₆ gases is stronger than that of CH₄. Furthermore, in order to improve the applicability of the Rh doped VSe₂ monolayer for the detection of oil-dissolved gases molecules. The effect of electric field on the sensing properties of gas molecules on Rh doped VSe₂ monolayers is also investigated. Finally, the desorption performance of the system is evaluated based on the transition state theory and Van’t-Hoff-Arrhenius expression. The findings of the study not only disclose the method by which the Rh doped VSe₂ monolayer detects the breakdown gasses in transformer oil, but they also offer theoretical recommendations for the advancement of VSe2-based sensors and scavengers.