Performance for CO gas sensing of janus ReSSe monolayer doped with Fe, Ru and Os from first principles calculation

Abstract Transition metal dichalcogenides (TMDs) have many excellent properties as promising class of two-dimensional materials. In this study, we conducted rigorous calculations utilizing density functional theory to evaluate the potential of Janus ReSSe monolayers, doped with transition metals such as Fe, Ru, and Os, in gas-sensitive applications specifically targeting CO detection. Three stable structures of X-Re 15 S 16 Se 16 Janus doped with X elements (X = Fe, Os, Ru) were designed. Our findings indicate that the C atom of the CO molecule exhibits a higher affinity for adsorbing onto the X (X = Fe, Os, Ru) transition metal atoms, forming robust X–C bonds, rather than the O atom. Among these bonds, the Os-C bond exhibits the strongest bonding states, followed by the Ru-C bond, while the Fe-C bond behaves the weakest. Notably, the d-orbital peaks of the X (X = Fe, Os, Ru) transition metals display distinct bonding strengths with the C atom. This research may provide a theoretical foundation for the development of new gas sensors based on two-dimensional materials.