Adsorption properties of sulfurous gas based on Fe, Co, Ni decorated SbP monolayer: A first-principles study

The adsorption properties of H2S and SO2 gases on monolayer antimonide phosphorus (SbP) are reported by using the density functional theory (DFT). The adsorption energies, charge transfer, electronic properties and recovery time of gas molecules adsorbed on the pure SbP and metal (Fe, Co, Ni) decorated SbP are computed to evaluate the sensing performance of monolayer SbP. Results indicate that metal decorating can dramatically improve the interaction between the substrate material and the gas molecules. The adsorption energies of H2S on the Fe, Co and Ni decorated SbP monolayer are -1.478 eV, -1.740 eV and -1.015 eV, respectively, which are much larger than the pure SbP (-0.293 eV). Especially, the adsorption of H2S gas by Ni-decorated SbP is not only strong physical adsorption, but also ensures the physical properties of the gas itself. By further applying biaxial strain to H2S/Ni-SbP, it can be found that the recovery time decreases (1.44 x 105-28.63 s) with increasing tensile strain. The adsorption and dissociation of H2S gas on Ni-decorated SbP can be controlled by temperature and biaxial strain. Therefore, we predict that the Ni-decorated SbP can be a promising H2S gas sensor candidate.