Theoretical screening of M₃-WS₂ for detecting environmentally toxic gases

High-performance gas detection is critical for effective monitoring of environmentally toxic gases. In this study, the adsorption performance of six toxic gas molecules adsorbed on M₃ clusters modified WS₂ (M₃-WS₂) are systematically discussed by using density functional theory calculations. Based on the binding energies and electronic structures, M₃-WS₂ systems are highly thermodynamically stable. Among the gases studied (CH₄, CO, H₂S, NH₃, NO, and NO₂), NO₂ exhibits the strongest adsorption on the M₃-WS₂ surface. The calculated adsorption energies for NO₂ on the four distinct M₃-WS₂ configurations are −3.780, −3.501, −3.370, and −3.236 eV, respectively. Considering its moderate adsorption energy, appreciable charge transfer, and rapid recovery time at room temperature, Pt₃-WS₂ emerges as a promising candidate for CH₄ sensing. In addition, raising the temperature can accelerate gas molecule desorption from the system. Ir₃-WS₂ emerges as a potential gas-sensitive material for the detection of H₂S with the recovery time of 689 s at 500 K. The work offers theoretical guidance for developing sustainable gas sensor for targeting the environmentally toxic gases.