A First-Principles Investigation of Monolayer MoS2 Doped with Mn and V as an Excellent NO2 Sensor with High Selectivity

This article conducts a comprehensive investigation into the adsorption properties of both pristine MoS2 monolayers and those doped with Mn and V, wherein these dopants replace Mo atoms. By the first-principles calculations, the research reveals a noteworthy reduction in the adsorption energy of NO2 on Mn-doped and V-doped MoS2 monolayers compared to pure MoS2 monolayers. Specifically, at the most favorable adsorption site, the adsorption energy decreases from -5.83 to 5.908 eV for Mn-doped MoS2 and from -5.58 to -6.17 eV for V-doped MoS2. Furthermore, computations of the band structure, work function, and charge density difference highlight a significant degree of charge transfer and coexistence of electrons within these systems. Additionally, post-adsorption of NO2 molecules, a distinct shift in the density of states (DOS) toward lower energy states is observed at the adsorption sites of both MoS2/Mn and MoS2/V monolayers, underscoring their exceptional sensitivity in detecting NO2. In summary, these results demonstrate the substantial potential of Mn-doped and V-doped MoS2 monolayers as highly sensitive materials for NO2 detection. Their lower adsorption energies and noteworthy shifts in DOS following NO2 adsorption enhance their capabilities as NO2 sensors.