2D GaC₃ Monolayer for Sensing Environmental Toxic/Nontoxic Gases (ETGs/ENTGs) under First-Principles Investigation

Monolayer GaC3 nanosheet was examined in this study as a potential sensor for ecologically toxic/nontoxic gases (ETGs/ENTGs), including O2, H2O, CO2, CO, NO, NO2, N2, and NH3. Nonequilibrium green’s function (NEGF) and first-principles approaches were employed to calculate and analyze the data. On the surface of the GaC3 nanosheet, we found variations in electronic parameters, e.g., adsorption energies, recovery time, charge transfer, work function, and I/V properties for these ETGs/ENTGs. In the presence of interacting gas molecules with the GaC3 nanosheet surface, all ETGs/ENTGs exhibit electron acceptor behavior. Among all ETGs/ENTGs, gas molecules NO2 and NH3 exhibit distinct magnetic effects after adsorption on the surface of monolayer GaC3. The longer recovery time of 0.57 s is a direct reflection of the best adsorption energy for the adsorbed NH3 molecule on the GaC3 nanosheet at ambient temperature. It is feasible that NH3 might be used as a one-time nonreversible gas sensor due to the fact that its recovery time is somewhat longer. The positive adsorption energy of NO2 molecules implies that they are not suited for gas detection devices. The relatively small adsorption energies of O2, CO2, H2O, CO, NO, and N2 have extremely short recovery times. As a finding, GaC3 appears to be a superior reversible sensor for oxygen-containing gases (O2, CO, CO2, and H2O) and nitrogen-containing gases (NO and N2). We found significant changes in I/V characteristics and sensitivity for ETGs/ENTGs adsorbed on the GaC3 monolayer, which illustrates its applicability to real-world applications. The present study successfully demonstrates that GaC3 may be employed to develop a gas sensor with outstanding sensing performance for ETGs/ENTGs.