First-Principle Insight into Ga-Doped MoS₂ for Sensing SO₂, SOF₂ and SO₂F₂

First-principle calculations were carried out to simulate the three decomposition gases (SO₂, SOF₂, and SO₂F₂) of sulfur hexafluoride (SF₆) on Ga-doped MoS₂ (Ga-MoS₂) monolayer. Based on density functional theory (DFT), pure MoS₂ and multiple gas molecules (SF₆, SO₂, SOF₂, and SO₂F₂) were built and optimized to the most stable structure. Four types of Ga-doped positions were considered and it was found that Ga dopant preferred to be adsorbed by the top of Mo atom (T_Mo). For the best adsorption effect, two ways of SO₂, SOF₂, and SO₂F₂ to approach the doping model were compared and the most favorable mode was selected. The adsorption parameters of Ga-MoS₂ and intrinsic MoS₂ were calculated to analyze adsorption properties of Ga-MoS₂ towards three gases. These analyses suggested that Ga-MoS₂ could be a good gas-sensing material for SO₂ and SO₂F₂, while it was not suitable for SOF₂ sensing due to its weak adsorption. This work provides a theoretical basis for the development of Ga-MoS₂ materials with the hope that it can be used as a good gas-sensing material for electrical equipment.