Influence of vacancy defects on 2D BeN₄ monolayer for NH₃ adsorption: a density functional theory investigation

Abstract

Two-dimensional (2D) materials have attracted a great deal of interest in developing nanodevices for gas-sensing applications over the years. The 2D BeN4 monolayer, a recently synthesized single-layered Dirac semimetal, has the potential to function as a gas sensor. This study analyses the ammonia (NH3) sensing capacity of the pristine and vacancy-induced BeN4 monolayers using first-principle density functional theory (DFT) calculations. As per the obtained results, the NH3molecule is adsorbed on pristine BeN4 via weak Van der Waals interaction (vdW) with a poor adsorption energy of -0.41 eV and negligible charge transfer. Introducing Be vacancy in BeN4 increases the NH3 adsorption energy to -0.83 eV due to improved charge transfer (0.044e) from defective monolayer to the NH3 molecule. The structural stability, suitable recovery time (74 s) at room temperature, and superior work function sensitivity promise the potential application of defective BeN4 as an NH3 sensor. This research will be a theoretical groundwork for creating innovative BeN4-based NH3 gas sensors.

Highly Efficient CuO-Anchored SnO2 Nanofiber for Low-Concentration H2S Gas Sensors

“…The following expression is used to calculate the charge density difference plot normalΔ ρ = ρ s u r f a c e + H 2 normalS − ρ normals normalu normalr normalf normala normalc normale Here, ρ surface+H 2 S and ρ surface are the charge density of the H 2 S-adsorbed surface and the surface, respectively. The plot in Figure also confirms the charge-donating nature of the H 2 S molecule.…”

Catechol Sensing Performance of Pd-Functionalized Two-Dimensional Polyaramid: A DFT Investigation

“…It can be described as the minimum energy essential for the material to transfer an electron from inside the material to its surface . The value of ϕ can be theoretically obtained from the equation given below ϕ = E v − E f where E v and E f are the energies of the surface under vacuum and Fermi levels in eV, respectively. After the adsorption of the analyte molecule on the substrate surface, a charge distribution occurs at the interface of the analyte and the surface, causing the formation of an interfacial dipole.…”

Metal (Ni, Pd, and Pt)-Doped BS Monolayers as a Gas Sensor upon Vented Gases in Lithium-Ion Batteries: A First-Principles Study

“…In recent years, researchers have been seeking different gas-sensing materials theoretically and experimentally for improving the selectivity and sensitivity of gas sensors. − Traditional metal oxide sensors have disadvantages such as poor selectivity, high energy consumption, and unfriendly to the environment. , The two-dimensional materials are naturally characterized by large areas, ultrahigh carrier mobilities, and rich surface active sites and have attracted great interest. − The application of two-dimensional materials in gas sensors may make up for the shortcomings of traditional metal oxide sensors and promote greatly the development of gas sensors. − Graphene, silicene, phosphorene, and MoS 2 have been studied for their gas-sensing properties, and some prospective results have been obtained. − However, the adsorption of some typical gases, such as CO and CO 2 on those materials is weak, and the interactions between their surfaces and various gases are usually not enough to ensure stable adsorption conditions. To handle this issue, methods like doping other atoms, introducing defects in suitable locations, molecular group functionalizing, and other modification techniques have been proposed. − Transition metal (TM) doping is one of the most widely used methods in gas sensing technology.…”