Adsorption of toxic gas molecules on pristine and transition metal doped hexagonal GaN monolayer: A first-principles study. (July 2019)

• Record Type: Journal Article
• Authors: Chen, Guo-Xiang; Li, Han-Fei; Wang, Dou-Dou; Li, Si-Qi; Fan, Xiao-Bo; Zhang, Jian-Min
• Is Part Of: Vacuum. Volume 165(2019)
• Page Start: 35
• Page End: 45
• Publication Date: 2019-07
• Subjects: GaN monolayer -- Transition-metal -- Toxic gas molecules -- Adsorption -- Density functional theory -- Gas sensing; Vacuum -- Periodicals; 621.55
• DOI: 10.1016/j.vacuum.2019.04.001
• Languages: English
• ISSNs: 0042-207X

Abstract

Abstract: Using the first-principles calculations based on density functional theory (DFT-D2 method), we systematically study the structural, energetic, electronic and magnetic properties of toxic gas molecules (H2 S, NH3 and SO2 ) adsorbed on pristine and transition metal (TM) atom (Fe, Mn) doped GaN monolayer (GaN-ML). The results show that the H2 S and NH3 are physisorbed on pristine GaN-ML with small adsorption energy, charge transfer, and long adsorption distance. While chemical adsorption character of SO2 on GaN-ML can be obtained, which means that the pristine GaN-ML is sensitive to SO2 . We find that the adsorption ability of pristine GaN-ML can be improved by introducing TM dopants. TM (Fe, Mn) doping can increase adsorption energy and charge transfer of the adsorbed systems, except for SO2 adsorbed Fe doped GaN-ML. The enhancing interaction between adsorbed molecules and the TM doped GaN-ML can dramatically induce electrical conductivity changes. Therefore, the TM doped GaN-ML is more suitable for gas molecules detection compared with the pristine GaN-ML. These present properties of gas molecules adsorbed on the pristine and TM doped GaN-ML will help to guide scientists to develop better two-dimensional GaN-based gas sensors in the future. Highlights: Adsorptions of toxic gas molecules on pristine and TM doped GaN-ML are studied by DFT-D2 method. The H2 S and NH3 are physisorbed on pristine GaN-ML, while chemical adsorption character of SO2 on GaN-ML can be obtained. TM doping is promising to improve gas molecules adsorption ability of pristine GaN-ML. The enhancing interaction between gas molecules and TM doped GaN-ML can induce electrical conductivity changes.