Ag Modified SnS 2 Monolayer as a Potential Sensing Material for C 4 F 7 N Decompositions: A Density Functional Theory Study.

As the field of 2D materials rapidly evolves, substances such as graphene, metal dichalcogenides, MXenes, and MBenes have garnered extensive attention from scholars in the gas sensing domain due to their unique and superior properties. Based on first-principles calculations, this work explored the adsorption characteristics of both intrinsic and silver (Ag) doped tin disulfide (SnS 2 ) toward the decomposition components of the insulating medium C 4 F 7 N (namely, CF 4 , C 3 F 6 , and COF 2 ), encompassing the adsorption energy, charge transfer, density of state (DOS), band structure, and adsorption stability. The results indicated that Ag-doped SnS 2 exhibited an effective and stable adsorption for C 3 F 6 and COF 2 , whereas its adsorption for CF 4 was comparatively weaker. Additionally, the potential for Ag-SnS 2 in detecting C 3 F 6 was highlighted, inferred from the contributions of the band gap variations. This research provides theoretical guidance for the application of Ag-SnS 2 as a sensing material in assessing the operational status of gas-insulated equipment.