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

Two-dimensional materials have attracted a great deal of interest in developing nanodevices for gas-sensing applications over the years. The 2D BeN4monolayer, a recently synthesized single-layered Dirac semimetal, has the potential to function as a gas sensor. This study analyzes the NH3sensing capacity of the pristine and vacancy-induced BeN4monolayers using first-principles density functional theory (DFT) calculations. As per the results, the NH3molecule is physisorbed on the pristine BeN4via weak Van der Waals interaction with a poor adsorption energy of -0.41 eV and negligible charge transfer. Introducing Be vacancy in BeN4increased the NH3adsorption energy to -0.83 eV due to the improved charge transfer (0.044 e) from the defective monolayer to the NH3molecule. The structural stability, sufficient recovery time (74 s) at room temperature, and superior work function sensitivity promise the potential application of defective BeN4as an NH3sensor. This research will be a theoretical groundwork for creating innovative BeN4-based NH3gas sensors.