Favorable adsorption and sensing properties of the HfS2 monolayer upon H2S and SOF2 gases by Pt-doping: A first-principles study

In this study, we employed first-principles theory to investigate the properties of Pt-doping in a pristine HfS2 monolayer, and to explore the adsorption behavior of the Pt-doped HfS2 (Pt-HfS2) monolayer when interacting with H2S and SOF2 molecules, aiming to harness its sensing capabilities. Our findings indicate that the Pt dopant can be stably anchored within the HfS2 monolayer, with a cohesive energy of-5.73 eV/atom. Besides, Pt-HfS2 monolayer engages in chemisorption with H2S, characterized by an adsorption energy of-0.95 eV, and physisorption with SOF2, with a comparatively weaker adsorption energy of-0.43 eV. Also, the charge transfer in the SOF2 system is more favorable than in the H2S system, leading to a more pronounced modulation in the bandgap of the Pt-HfS2 monolayer. Consequently, the Pt-HfS2 monolayer is evidenced by a better sensing response of- 56.7 % to SOF2 compared with that of- 29.6 % to H2S. Moreover, the analysis of recovery property reveals the reusability of Pt-HfS2 monolayer as a resistive sensor. These findings uncover the potential of the purposed PtHfS2 monolayer for sensing application targeting H2S and SOF2, which is crucial to evaluate the operation status of SF6-insulation devices. Our work lays the groundwork for exploration of innovative HfS2-based sensing materials for gas sensing in electrical engineering and potentially in various environmental and industrial settings.