Transition metal-doped ZrS2 monolayer as potential gas sensor for CO2, SO2, and NO2: Density Functional Theory and Non-equilibrium Green’s Functions’ analysis

Abstract We employ density functional theory combined with non-equilibrium Green’s functions to systematically analyze the adsorption and sensing properties of a pristine ZrS 2 monolayer doped with transition metals, Ni, Pd, or Pt, for three target gases: CO 2 , SO 2 , and NO 2 . The findings reveal that the pristine ZrS 2 monolayer exhibits only a weak physical adsorption, whereas its transition metal-doped monolayers show significantly enhanced sensing capa-bilities. Notably, the adsorption of NO 2 leads to substantial modifications in the band structure of ZrS 2 monolayer, suggesting its use as a resistive NO 2 sensor. Recovery time calculations indicate that the Ni-ZrS 2 monolayer demonstrates strong capture ability for SO 2 and NO 2 due to their prolonged recovery times. Conversely, the Pd-ZrS 2 and Pt-ZrS 2 monolayers exhibit shorter recovery times at temperatures 348 K and 398 K after adsorbing SO 2 and NO 2 , highlighting their suitability for repeated detection. Additionally, charge trans-port calculations reveal that a Ni-ZrS 2 -based device excels in sensing NO 2 , while a Pd-ZrS 2 -based one is optimal for detecting CO 2 and NO 2 , and a Pt-ZrS 2 -based device has a superior sensitivity to SO 2 .