TM (Pd, Cu, Mo) Modified ZrSe₂ Monolayer: A Promising Sensing Material for Environmentally Friendly Insulating...

The C₅F₁₀O/CO₂ mixed gas has emerged as a highly promising alternative to SF₆ due to its exceptional environmental and insulating properties. However, during partial discharge faults within electrical equipment, this mixture decomposes to produce characteristic gases such as C₂F₄, CO, and COF₂, posing threats to both environmental safety and equipment integrity. Based on first-principles, the adsorption effect and sensing ability of the ZrSe₂ monolayer modified by transition metal TM (TM = Pd, Cu, Mo) for the three gases were analyzed. The most stable doping site (T_H site) was identified through binding energy analysis, and the thermodynamic properties were calculated to confirm that all doping structures exhibit excellent thermal stability. We also investigated the adsorption energy, distance, and charge transfer, followed by an analysis of the differential charge density (DCD), density of states (DOS), and desorption properties to assess the sensing performance of each system. The results show that the adsorption effect of substrates is obviously enhanced after TM modification compared with intrinsic ZrSe₂. Specifically, the Mo-ZrSe₂ monolayer is an ideal reusable C₂F₄ sensor material, while, due to its excessively prolonged desorption time after CO adsorption, it is indicated that it is more suitable for use as a permanent CO capture agent. Pd-ZrSe₂ and Cu-ZrSe₂ exhibit excellent adsorption capacity for CO, and CO can desorb rapidly from their surfaces at extremely high temperatures. Not only does this work deepen the understanding of sensing mechanisms, but it also identifies prospective materials that could drive the evolution of gas-sensitive devices.