Study on Gas Adsorption Properties (N2, H2, O2, NO, NO2, CO, CO2, SO2, H2S, H2O and NH3) on the O-vacancy-containing Sc2CO2 Monolayer

In this work, we have studied the (N2, H2, O2, NO, NO2, CO, CO2, SO2, H2S, H2O, and NH3) gases adsorption properties on the O-vacancy-containing Sc2CO2 monolayer by first-principles calculations. We have determined the preferred adsorption positions and the structural features of the O-vacancy-containing Sc2CO2 monolayer after adsorption of different gas molecules. The adsorption energy and charge transfer from the monolayer to the gas molecules have been calculated. The calculated results show that H2, N2, NH3, H2S and H2O molecules are physisorbed, while CO2, CO, NO2, NO, O2 and SO2 molecules are chemisorbed in the neighboring area of the O-vacancy of the Sc2CO2 monolayer. The existence of the O-vacancy significantly enhances the CO and CO2 adsorption intensity of the defect Sc2CO2 monolayer compared to the original Sc2CO2 monolayer. Our results show that the O-vacancy-containing Sc2CO2 monolayer can be used for detecting NO gas as a resistive sensor.