DFT Study of Zn-Modified SnP(3): A H(2)S Gas Sensor with Superior Sensitivity, Selectivity, and Fast Recovery Time

The adsorption properties of Cu, Ag, Zn, and Cd-modified SnP(3) monolayers for H(2)S have been studied using density functional theory (DFT). Based on phonon spectrum calculations, a structurally stable intrinsic SnP(3) monolayer was obtained, based on which four metal-modified SnP(3) monolayers were constructed, and the band gaps of the modified SnP(3) monolayers were significantly reduced. The adsorption capacity of Cu, Zn-modified SnP(3) was better than that of Ag, Cd-modified SnP(3). The adsorption energies of Cu-modified SnP(3) and Zn-modified SnP(3) for H(2)S were −0.749 eV and −0.639 eV, respectively. In addition, Cu-modified SnP(3) exhibited chemisorption for H(2)S, while Zn-modified SnP(3) exhibited strong physisorption, indicating that it can be used as a sensor substrate. Co-adsorption studies showed that ambient gases such as N(2), O(2), and H(2)O had little effect on H(2)S. The band gap change rate of Zn-modified SnP(3) after adsorption of H(2)S was as high as −28.52%. Recovery time studies based on Zn-modified SnP(3) showed that the desorption time of H(2)S was 0.064 s at 298 K. Therefore, Zn-modified SnP(3) can be used as a promising sensor substrate for H(2)S due to its good selectivity, sensitivity, and fast recovery time.