Interfacial Electronic Modulation and Sensing Mechanisms of CO, C₂F₄, and COF₂ on MO_x-Modified V₂CF₂ MXene for C₄F₇N...

To meet the demand for online monitoring of fault byproducts generated from eco-friendly insulating gases in electrical equipment, density functional theory (DFT) calculations were performed to investigate CO, C₂F₄, and COF₂ adsorption on NiO-, TiO₂-, and MoO₃-modified V₂CF₂ MXene. All oxide modifiers form thermodynamically stable MO_x/V₂CF₂ interfaces and significantly regulate the electronic properties of V₂CF₂. Adsorption results reveal distinct oxide-dependent selectivity. CO exhibits the strongest adsorption on NiO-V₂CF₂ (E_ads = -1.490 eV), while NiO modification also enhances interactions with fluorinated gases, giving adsorption energies of -0.817 eV for C₂F₄ and -0.687 eV for COF₂. Density-of-states analysis indicates evident interfacial orbital hybridization and charge redistribution after gas adsorption. Desorption kinetics and ab initio molecular dynamics (AIMD) analyses demonstrate favorable cyclic recoverability within practical temperature windows. NiO-V₂CF₂ enables rapid COF₂ recovery at 298 K (τ = 0.411 s) and room-temperature recoverability for C₂F₄ (τ = 65.9 s), whereas CO regeneration is fastest on TiO₂-V₂CF₂ at 398 K (τ = 7.27 s) and remains feasible on MoO₃-V₂CF₂ at 298 K (τ = 110 s). These results provide theoretical guidance for MXene-based sensing materials for eco-friendly insulating-gas monitoring.