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

ABSTRACT

The adsorption of five small gas molecules (CO, CO2, NO, NO2, and NH3) on transition metal (TM)-modified ZrSe2 monolayers (Au-ZrSe2 and Pt-ZrSe2) are studied based on first principles. The adsorption structure, adsorption energy (Eads), electron transfer (Qt), and density of states (DOS) with intrinsic 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 intrinsic ZrSe2 adsorbs the five kinds of gas molecules weakly, while ZrSe2 modified by the Au or Pt atom improves the adsorption of the gas molecules in different degrees. Au-ZrSe2 has the best adsorption effect on NO2 gas molecules, while Pt-ZrSe2 shows strong sensitivity to CO gas molecules. Moreover, Au-ZrSe2 and Pt-ZrSe2 are of great significance for the adsorption sensing mechanism and also offer prospective materials for the advancement of gas-sensitive sensors.