CO- and H ₂ S-adsorbed one-dimensional AlSi structures for gas sensing applications

The potential applications of low-dimensional materials continue to inspire significant interest among researchers worldwide. This study investigates the properties of one-dimensional AlSi monolayers, specifically AlSi nanoribbons, and their adsorption behaviour with CO and H₂S molecules. The electronic, magnetic and optical properties of these systems are calculated using density functional theory and the Vienna Ab initio Simulation Package. Results indicate that the structures remain relatively planar with negligible buckling heights. All three studied structures exhibit non-zero magnetic moments; notably, CO adsorption enhances the magnetic moment of the pristine AlSi nanoribbon, whereas H₂S adsorption reduces it. Adsorption energy calculations reveal that CO exhibits stronger adsorption compared to H₂S. Furthermore, a detailed investigation of the optical properties-including the real and imaginary parts of the dielectric function, absorption coefficient and electron-hole density-demonstrates the potential of these structures in nanotechnology applications, particularly for CO and H₂S gas sensing.