An Ag-modified GaAlTe2 monolayer: a high-performance gas sensor for detecting asphyxiating gases

Abstract

Asphyxiating gases such as methane (CH₄), carbon monoxide (CO), and hydrogen sulfide (H₂S) pose a serious threat to human health by displacing oxygen from the environment, leading to suffocation. Therefore, detecting these gases is crucial for ensuring human health and safety. This study explores the sensing mechanism of an Ag-functionalized GaAlTe₂ monolayer using density functional theory to detect asphyxiating gases such as CH₄, CO, and H₂S. The adsorption properties are evaluated by calculating the adsorption energies, electronic characteristics, charge transfer, work function, and recovery time. Notable variations in the electronic characteristics and suitable adsorption energies ensure that the Ag–GaAlTe₂ monolayer effectively detects CH₄, CO, and H₂S. The adsorption energies of CH₄, CO, and H₂S on the Ag–GaAlTe₂ monolayer are −0.103 eV, −0.631 eV, and −0.605 eV, respectively. Adsorption of CH₄, CO, and H₂S on the Ag–GaAlTe₂ monolayer alters the work function by 2.82%, 3.94%, and 14.48%, respectively, demonstrating high gas sensitivity of the monolayer. The recovery times of the gases CH₄, CO, and H₂S adsorbed on the Ag–GaAlTe₂ monolayer are 0.054 ns, 0.039 s, and 0.015 s, respectively, ensuring the sensor's reusability. The results ensure that the Ag–GaAlTe₂ monolayer is a high-performance gas sensor for detecting asphyxiating gases.