Adsorption of small pollutant molecules on monolayer blue phosphorus

Abstract

Binding, electronic and optical properties of small pollutant molecules adsorbed on pristine monolayer blue phosphorus (BlueP) are investigated using the density functional theory (DFT). Ozone (O3), sulfur trioxide (SO3), hydrogen selenide (H2Se), sulfur dichloride (SCl2) and acetylene (C2H2) molecules are considered to explore the efficiency and versatility of the BlueP as a gas sensor in comparison with other materials. Results show while O3, SO3 have high binding energy (>0.5 eV/molecule), H2Se, SCl2 and C2H2 exhibit small binding energies (<0.5 eV/molecule) on BlueP. However, even when SCl2 and C2H2 interact weakly with BlueP, a strong modification is observed in the density of states, electronic band structure and the optical absorption of BlueP by the reduction of electronic and optical gaps from ∼2.1 eV to ∼1.5 eV. These changes in electronic and optical properties are some mandatory pre-requisites for any sensing material. Thus, our results suggest that BlueP can be considered as a promising candidate to solve different current problems of environmental pollution.