A DFT Study of the Ag-Doped h-BN Monolayer for Harmful Gases (NO2, SO2F2, and NO)

In the post-epidemic era, the rapid recovery of industry and commerce has significantly improved the economic development level of countries. However, the attendant problem of harmful gas emissions has received renewed attention. To solve this problem, the first thing is to use appropriate methods for real-time, accurate, and convenient monitoring of harmful gases. In this study, based on the first-principles density functional theory, we proposed an Ag-doped h-BN monolayer gas sensor for monitoring harmful gases (NO2, SO2F2, and NO). The DMol3 and CASTEP modules were used to optimize the molecular structures, and the optimal structure was obtained through a large number of calculations. Then, the adsorption process was modeled and simulated according to different positions and orientations. The results show that the proposed Ag-doped h-BN monolayer is very effective for the detection of three kinds of harmful gases. The adsorption between the substrate and the target gas is between physical adsorption and chemical adsorption, and the gas sensing performance is SO2F2 > NO2 > NO. In this study, the microscopic gas sensing mechanism and macroscopic gas sensing characteristics were clarified from the theoretical point of view, in order to provide a theoretical basis for the preparation of Ag-doped h-BN monolayer and provide new ideas and ways for the development of gas sensors.