Sensing of nitrogenous toxic gases on X-SnSe2/SnO2 heterostructures by doping with rare earth (X=La, Pr)

The detection of toxic gases, particularly nitrogenous ones, has a direct impact on human health and safety. This study investigated the adsorption behavior of four nitrogenous gases (NO 2 , NO, NH 3 , and HCN) using density functional theory. These gases were detected using a heterostructure of SnSe 2 /SnO 2 doped with rare-earth elements (La and Pr). Analysis of the results revealed distinct reaction patterns on both heterostructures. For nitrogenous gases containing oxygen, high adsorption energies (E ads ), high charge transfer (Q t ), and a high work function were observed, particularly in Pr-SnSe 2 /SnO 2 , where the highest values ​​reached -2.75 eV, -0.34e, and 5.76 eV, respectively, upon adsorption of NO 2 . The results also indicate a significant convergence of these values ​​for both heterostructures upon the adsorption of hydrogen-containing gases. This study demonstrates that Pr-SnSe 2 /SnO 2 is more effective at sensing oxygen-containing gases than hydrogen-containing gases, making it a promising sensor for this class of gases.