Adsorption and Gas-Sensing Performance of the Small-Molecule Gas on ZrSe2 Monolayers: A First-Principles Study

The adsorption of five small gasmolecules (CO, CO2,NO, NO2, and NH3) on transition metal (TM)-modifiedZrSe(2) monolayers (Au-ZrSe2 and Pt-ZrSe2) are studied based on first principles. The adsorption structure,adsorption energy (E (ads)), electron transfer(Q (t)), and density of states (DOS) withintrinsic ZrSe2, Au-ZrSe2, and Pt-ZrSe2 monolayers are discussed, and their sensing performance is evaluated.The results show that the electrical conductivity of ZrSe2 is obviously increased after Au and Pt atom modification. The intrinsicZrSe(2) adsorbs the five kinds of gas molecules weakly, whileZrSe(2) modified by the Au or Pt atom improves the adsorptionof the gas molecules in different degrees. Au-ZrSe2 hasthe best adsorption effect on NO2 gas molecules, whilePt-ZrSe2 shows strong sensitivity to CO gas molecules.Moreover, Au-ZrSe2 and Pt-ZrSe2 are of greatsignificance for the adsorption sensing mechanism and also offer prospectivematerials for the advancement of gas-sensitive sensors.