Adsorption Properties of Dissolved Gas Molecules in Transformer Oil on the ReSe₂ Monolayer: A DFT Study

Based on density functional theory, the adsorption behavior of seven typical dissolved gas molecules (CO, CO₂, H₂, CH₄, C₂H₂, C₂H₄, and C₂H₆) and H₂O molecule on the ReSe₂ monolayer was systematically investigated. The interactions between the ReSe₂ monolayer and eight gas molecules were investigated by calculating the adsorption energies, charge transfer, density of states (DOS), and deformation charge density (DCD) for eight different adsorption systems. The gas sensitivity of the ReSe₂ monolayer toward these gases was studied using frontier molecular orbital theory and work function analysis. The results demonstrate that compared to other gas molecules, the ReSe₂ monolayer exhibits a stronger interaction with CO with an adsorption energy of -1.49 eV. It also displays excellent sensitivity and selectivity toward CO making it a promising candidate for CO gas sensing applications. We aspire that this research will offer theoretical guidance for the development of ReSe₂-based gas sensors and contribute to state monitoring technology in oil-immersed power equipment.