Adsorption properties of ZnO-modified MoTe2 monolayers on H2, CO2, C2H6 gases

Through first-principles DFT calculations, this study investigated the adsorption properties of ZnO-modified MoTe₂ towards dissolved transformer insulating gases: H₂, CO₂, C₂H₆. The modified configuration of ZnO on MoTe₂ was optimized with binding energy of −2.180 eV, ensuring its structural stability of ZnO-MoTe₂ during gas adsorption. The results show that the modification of ZnO changes the energy band structure of the MoTe₂ monolayer, and the ZnO acts as an electron acceptor obtaining −0.452 e from the substrate. Compared with pristine MoTe₂ monolayers, ZnO-MoTe₂ material demonstrates shortened adsorption lengths and enhanced adsorption energies toward all target gases H₂, CO₂, C₂H₆. The deformation charge density, density of states, frontier molecular orbital analysis, and recovery time results show that ZnO-MoTe₂ system exhibits adsorption strength in the order C₂H₆>CO₂>H₂. This work provides theoretical foundations for developing ZnO-MoTe₂-based gas sensors with enhanced sensitivity, particularly for C₂H₆ detection, which can be a potential method for transformer condition monitoring.