Favorable Adsorption and Detection Properties of Metal Oxides (NiO and Ag₂O) Modified Janus SnSSe Monolayer Toward SF₆ Decomposition Gases in a Gas-Insulated Equipment

As the main monitoring method for the operation status and faults of gas-insulated equipment (GIE) equipment, SF6 decomposition gas analysis technology has been continuously upgraded, and the development of new gas-sensitive materials has always been one of the core breakthroughs. Herin, it is proposed the NiO and Ag2 O metal oxide-doped Janus tin sulfide selenide (SnSSe) (MOS-SnSSe) monolayers as prospective sensing materials for detection of four typical decomposition gases, namely, HF, SO2, SOF2, and SO2F2, to provide an option for upgrading the gas-sensitive units. The results suggest that the NiO and Ag2 O dopants are more inclined to stick to the S-surface of intrinsic SnSSe monolayer. Furthermore, the Mulliken analysis reveals the function of carrier-migration bridge of the NiO and Ag2 O dopants in the gas-sensing reaction that encourages the bidirectional migration of charges between the gas species and the SnSSe surface. The change in energy band confirms the adjusted electronic performances of MOS-SnSSe monolayers upon adsorbing gases, and the density of state redistribution in such four gas systems verifies the chemisorption of HF, SO2, SOF2, and SO2F2 on NiO-SnSSe monolayer, the chemisorption of HF and SO2 on Ag2 O-SnSSe monolayer, and the physisorption of SOF2 and SO2F2 on Ag2 O-SnSSe monolayer. Furthermore, our outcome demonstrates that the NiO-SnSSe monolayer is a feasible candidate for an SO2 resistive sensor operating at 458 K, while Ag2 O-SnSSe monolayer can serve as both a work-function-type sensor for such four gas SPICEs and a scavenger for SO2. These discoveries in this research expose the admirable gas sensitivity potentiality of the SnSSe-based system and the special attribute of the Janus community, which we anticipate could motivate more cutting-edge research in the industry of gas sensing.