Sensing mechanism and optical properties of hydrogen sulfide gas on the surface of precious metal Pt-modified VO₂ surface: a first-principles study

This paper investigates the adsorption behavior and optical properties of hydrogen sulfide gas on vanadium dioxide surfaces and noble metal-decorated vanadium dioxide surfaces using first-principles calculations based on the generalized gradient approximation within density functional theory. The results indicate that hydrogen sulfide gas exhibits physisorption on the vanadium dioxide surface, with an adsorption energy of –0.609 eV, while it undergoes chemisorption on the noble metal-decorated vanadium dioxide surface, with an adsorption energy of –1.923 eV. Furthermore, the optical properties of four different systems were calculated. Within the visible light range, the absorption capacity of these systems, in descending order, is as follows: hydrogen sulfide absorbed on noble metal-decorated vanadium dioxide surface, noble metal-decorated vanadium dioxide surface, hydrogen sulfide absorbed on vanadium dioxide surface, and vanadium dioxide surface alone. The results suggest that the hydrogen sulfide gas-sensing sensitivity is significantly enhanced while noble metals are loaded, and the response to visible light is also considerably improved. Ultimately, this study is expected to provide theoretical support for the research of vanadium dioxide-based hydrogen sulfide gas optical gas-sensing materials.