An investigation, within dispersion-corrected density functional theory, of the electronic and magnetic behavior of diatomic molecules adsorbed on modified MoS2 monolayers containing coinage metals embedded in sulfur trivacancies is reported. The selective electronic responses induced by gas adsorption highlight the strong potential of these systems for gas-sensing applications. Attention is given to small diatomic molecules of environmental relevance, such as NO, CO, and O2, whose mitigation and/or detection remain critical challenges. Results demonstrate that incorporation of group 11 metals into sulfur vacancies significantly enhances the adsorption capability of MoS2 monolayers. Strong adsorption energies, reaching up to ¿46.157 kcal·mol¿1 (¿2.001 eV), are observed, especially in Cu-doped systems, indicating their suitability for gas capture and sensing. Density of states and projected density of states analyses reveal notable changes in the electronic structure upon adsorption. In particular, a copper trimer embedded into a trivacancy of sulfur exhibits state splitting upon CO adsorption on it, identifying it as a promising chemiresistive sensor candidate. The Ag- and Au-doped systems interacting with NO display pronounced modifications in their PDOS profiles and magnetic moments, with total magnetic moments exceeding 1 ¿B and half-metallic behavior that favors spin-up electron conduction. These charge-transfer and magnetic responses enable tunable electronic and magnetic properties. This work provides valuable insight into defect-engineered MoS2 monolayers and establishes embedded coinage metals as effective design elements for advanced environmental monitoring and pollutant detection sensors but limited by the continuous introduction of defect states in the bandgap.
