Adsorption of gas molecules on a graphitic GaN sheet and its implications for molecule sensors. Issue 80 (2nd November 2017)

• Record Type: Journal Article
• Authors: Yong, Yongliang; Cui, Hongling; Zhou, Qingxiao; Su, Xiangying; Kuang, Yanmin; Li, Xiaohong
• Is Part Of: RSC advances. Volume 7:Issue 80(2017)
• Page Start: 51027
• Page End: 51035
• Publication Date: 2017-11-02
• Subjects: Chemistry -- Periodicals; 540.5
• DOI: 10.1039/c7ra11106a
• Languages: English
• ISSNs: 2046-2069

Abstract

Abstract : Motivated by the recent realization of two-dimensional nanomaterials as gas sensors, we have investigated the adsorption of gas molecules (SO2, NO2, HCN, NH3, H2 S, CO, NO, O2, H2, CO2, and H2 O) on the graphitic GaN sheet (PL-GaN) using density functional theory calculations. Abstract : Motivated by the recent realization of two-dimensional (2D) nanomaterials as gas sensors, we have investigated the adsorption of gas molecules (SO2, NO2, HCN, NH3, H2 S, CO, NO, O2, H2, CO2, and H2 O) on the graphitic GaN sheet (PL-GaN) using density functional theory calculations. It is found that among these gases, only SO2 and NH3 gas molecules are chemisorbed on the PL-GaN sheet with apparent charge transfer and reasonable adsorption energies. The electronic properties (especially the electric conductivity) of the PL-GaN sheet showed dramatic changes after the adsorption of NH3 and SO2 molecules. However, the strong adsorption of SO2 on the PL-GaN sheet makes desorption difficult, which precludes its application to SO2 sensors. Therefore, the PL-GaN sheet should be a highly sensitive and selective NH3 sensor with short recovery time. Furthermore, the adsorption of NO (or NO2 ) molecules introduces spin polarization in the PL-GaN sheet with a magnetic moment of about 1 μ B, indicating that magnetic properties of the PL-GaN sheet are changed obviously. Based on the change of magnetic properties of the PL-GaN sheet before and after molecule adsorption, the PL-GaN sheet could be used as a highly selective magnetic gas sensor for NO and NO2 detection.