Monolayer AlC₃: Mechanical, Thermoelectric, and Promising Sensing Properties for Environmentally Toxic/Nontoxic Oxygen-Containing Gases

This work investigated the possibility of a monolayer AlC₃ nanosheet as an optimistic sensor for ecologically poisonous/harmless oxygen-containing gases (OCGs), which includes CO, CO₂, and H₂O, implementing nonequilibrium Green's function (NEGF) and first-principles computations. The sensing properties of a pure AlC₃ monolayer were explored in this study, including their mechanical and thermoelectric properties. The pristine AlC₃ has a maximum mobility in the armchair direction for the hole carrier of 62797.44 cm² V^-1 s^-1. At room temperature, the value of electrical conductivity (σ), thermal conductivity (κ), figure of merit (<i>ZT</i>), and Seebeck coefficient (<i>S</i>) are 2.07 × 10¹⁸ S m^-1, 3.84 × 10¹³ W m^-1 K^-1 s^-1, 0.64, and -199.35 × 10^-6 V K^-1, respectively. On the surface of the AlC₃ nanosheet, we found variability in adsorption energies, electronic parameters, charge transfer, recovery time, work function, and <i>I</i>/<i>V</i> transport properties for these OCGs. When gas molecules cooperate with the surface of the AlC₃ nanosheet, all of the OCGs exhibit electron acceptor behavior. The OCGs (CO, CO₂, and H₂O) are noticed to have relatively short recovery times, though, because of their low adsorption energies. Overall, due to the remarkably short recovery time of OCGs, monolayer AlC₃ proves to be an outstanding multigas reversible sensor material designed for CO, CO₂, and H₂O. As a result, AlC₃ seems to be an excellent reversible sensor for CO, CO₂, and H₂O. We found remarkable variations in transport (<i>I</i>/<i>V</i>) properties and sensitivity for OCGs adsorbed on the AlC₃ monolayer, which illustrates its applicability for real-world applications. The current study successfully demonstrates that the AlC₃ monolayer may be utilized to create a gas sensor with outstanding sensing performance and also thermoelectric efficiency.