Environmental Gas Adsorption on SnGe2N4: A Theoretical Perspective

This is the authors' abstract. We don't add key points for this paper.

Based on spin-polarized density functional theory (DFT) calculations, a systematic study was conducted on the adsorption behavior of gas molecules such as H 2, CO, CO 2, H 2 O, NO 2, H 2 S, NH 3, and CH 4 on the SnGe 2 N 4 monolayer surface. The results indicate that all gas molecules exhibit relatively low adsorption energies and large adsorption distances on the SnGe 2 N 4 surface, suggesting a tendency toward physisorption. Charge density difference (CDD) and Bader charge analysis demonstrate minimal charge transfer, confirming weak interactions between the gas molecules and the SnGe 2 N 4 surface. Analyzing the band structures and density of states of SnGe 2 N 4 monolayers adsorbed with different gas molecules reveals that except for NO 2 and H 2 S, the adsorption of other gas molecules does not significantly affect the electronic properties of the SnGe 2 N 4 surface. Notably, NO 2 adsorption induces spin polarization, potentially influencing the sensing mechanism. Notably, the adsorption energy of NO 2 on the SnGe 2 N 4 surface (−1.08 eV) is significantly higher than that of other gas molecules, and NO 2 exhibits the most significant charge transfer (−0.051 e ) with the SnGe 2 N 4 surface. Our findings provide fundamental insights into the gas adsorption properties of SnGe 2 N 4, which could be beneficial for its application in gas sensing technologies.