First-principles study of pristine and metal decorated blue phosphorene for sensing toxic H2S, SO2 and NO2 molecules

Abstract

First-principles calculations based on density functional theory (DFT-D2 method) are employed to systematically investigate the adsorption behaviors of toxic gas molecules (H2S, SO2 and NO2) on pristine and metal (Li, Al, Ni and Pt) decorated blue phosphorene. The results for small adsorption energy, charge transfer and large adsorption distance reveal that the adsorption of H2S, SO2 and NO2 on pristine blue phosphorene is physisorption. It has been proved that the adsorption ability of pristine blue phosphorene to gas molecules can be improved by metal decorating, except for H2S adsorbed on Al decorated blue phosphorene. Our calculations show that the gas molecules absorbed on metal decorated blue phosphorene belong to chemisorption with relatively large adsorption energies and charge transfer, while the H2S adsorbed on Li and Al decorated blue phosphorene are still physisorption. Meanwhile, the significant conductivity changes of these systems mean the sensitivity of gas molecules improved. From the calculated recovery time, we find that gas molecules desorption from metal decorated blue phosphorene is possible. Therefore, these results indicate that metal decorated blue phosphorene could be ideal candidate for better adsorption or detection toxic H2S, SO2 and NO2 molecules.