A graphene-like BeS monolayer as a promising gas sensor material with strain and electric field induced tunable response: a first-principles study

A comprehensive investigation of the gas sensing potential of BeS monolayer has been conducted using DFT calculations. Twelve common pollutant gases: NH(3), NO(2), NO, CO, CO(2), CH(4), H(2), O(2), N(2), H(2)S, H(2)O and SO(2), have been studied. Our analysis reveals defect states in the band structure near the Fermi level and strong hybridization between gas molecule orbitals and the BeS monolayer. We observe higher adsorption energies for NH(3) and CO compared to other popular gas sensing materials. The optical properties of CO(2) and NO(2) adsorbed on the BeS monolayer show increased reflectivity and absorption coefficient in the UV and far infrared region. Tensile strain has minimal impact on adsorption energy, while biaxial compressive strains enhance the gas sensing capability of the BeS monolayer. The application of an electric field offers control over gas adsorption and desorption. We propose the BeS monolayer as a promising candidate for future gas molecule sensing applications due to its high adsorption energy, rapid recovery time, and distinct optical properties.