First‐Principles Insight Into Adsorption Characteristics of Ir‐Embedded HfS ₂ Monolayers for Gas‐Sensing of H ₂ S, SOF ₂ , and SO ₂ F ₂

Abstract Utilizing the first‐principles theory, this study delves into the adsorption characteristic and the sensing potential of Ir‐embedded HfS 2 (Ir─HfS 2 ) monolayer upon three SF 6 decomposed species: H 2 S, SOF 2 , and SO 2 F 2 . One S atom is replaced by an Ir atom in the pristine HfS 2 monolayer to establish the Ir─HfS 2 monolayer, yielding cohesive, and formation energies of −5.76 eV/atom and 2.87 eV, respectively. The monolayer exhibits chemisorption with H 2 S and SOF 2 , while physisorption is observed with SO 2 F 2 . The bandgap alternation upon gas adsorption follow the order SOF 2 > H 2 S > SO 2 F 2 with SO 2 F 2 showing no change. In conjunction with the analysis of recovery properties, the Ir─HfS 2 monolayer demonstrates favorable reusability as a resistive sensor, exhibiting high sensitivity for the detection of SOF 2 at room temperature. Conversely, detecting H 2 S requires a brief heating process at 498 K prior to initiating the next sensing cycle. These insights highlight the significant potential of Ir─HfS 2 monolayer for sensing SF 6 decomposed species, paving the way for future explorations into HfS 2 ‐based materials for gas sensing applications in electrical engineering and diverse environmental and industrial contexts.