Adsorption of NO gas molecule on the vacancy defected and transition metal doped antimonene: A first-principles study

The adsorption behaviors of single vacancy defected and transition metal (TM) atoms (Sc, Ti) doped antimonene for NO molecule have been systematically investigated using the first-principles calculations based on the density functional theory (DFT-D2 method). The results show that the NO molecule is physisorbed on pure antimonene with the low adsorption energy. While the NO molecule is chemisorption on single vacancy defected antimonene (SV-antimonene), TM doped antimonene (Sc-antimonene, Ti-antimonene) and TM doped single vacancy defected antimonene (Sc-SV-antimonene, Ti-SV-antimonene). The introduction of vacancy defects and TM atoms can effectively enhance the interaction between the NO molecule and the antimonene by analyzing the density of states (DOS), charge density difference (CDD) and the electron localization function (ELF). In addition, the significant changes in work function (WF) after NO adsorption indicate that defected and doped antimonene are sensitive to NO molecule. The optical properties suggest that the increase in absorption coefficients of all adsorption systems can be observed in the visible region. Therefore, these results provide theoretical guidance for the design of high-sensitive gas sensors based on antimonene.