Investigation of novel two-dimensional B2CO monolayer and its high sensing performance in detecting nitrogen-containing gases: A combined density functional theory calculation and non-equilibrium Green's function study

Abstract

Two-dimensional (2D) materials have attracted widespread attention because of their excellent optical and electrical properties and have been extensively studied as gas sensors. A new type of 2D material, the B2CO monolayer, has recently been reported to possess significant structural, energetic, and thermodynamic stability. In this study, density functional theory (DFT) was used to explore the sensing properties of CO, CO2, NH3, NO, and NO2 gas molecules on the B2CO monolayer. After adsorption, the NH3, NO, and NO2 molecules formed chemical bonds with the B2CO monolayer. Among these, the NO2 molecule has the highest muscular adsorption energy in the B2CO monolayer. Based on electronic analysis, the B2CO monolayer can provide robust electron interactions with NO and NO2 molecules. Furthermore, the simulated current–voltage curves showed that the increasing amplitude of the current response for the adsorption of the NO2 molecule is more significant than that for NO. Thus, the calculated sensitivity for the NO2 molecules was much higher than that for the NO molecules in the B2CO monolayer. Based on these results, we predict that the B2CO monolayer will have a much higher sensing performance for detecting nitrogen-containing gases (NCGs) molecules than CO and CO2 molecules, especially NO2 molecules.