Nitrogen-Based Gas Molecule Adsorption on a ReSe₂ Monolayer via Single-Atom Doping: A First-Principles Study

Two-dimensional materials have shown immense promise for gas-sensing applications due to their remarkable surface-to-volume ratios and tunable chemical properties. However, despite their potential, the utilization of ReSe₂ as a gas-sensing material for nitrogen-containing molecules, including NO₂, NO, and NH₃, has remained unexplored. The choice of doping atoms in ReSe₂ plays a pivotal role in enhancing the gas adsorption and gas-sensing capabilities. Herein, the adsorption properties of nitrogen-containing gas molecules on metal and non-metal single-atom (Au, Pt, Ni, P, and S)-doped ReSe₂ monolayers have been evaluated systematically via ab initio calculations based on density functional theory. The findings strongly suggest that intrinsic ReSe₂ has better selectivity toward NO₂ than toward NO and NH₃. Moreover, our results provide compelling evidence that all of the dopants, with the exception of S, significantly enhance both the adsorption strength and charge transfer between ReSe₂ and the investigated molecules. Notably, P-decorated ReSe₂ showed the highest adsorption energy for NO₂ and NO (-1.93 and -1.52 eV, respectively) with charge transfer above 0.5e, while Ni-decorated ReSe₂ exhibited the highest adsorption energy for NH₃ (-0.76 eV). In addition, on the basis of transition theory, we found that only Au-ReSe₂ and Ni-ReSe₂ can serve as reusable chemiresisitve gas sensors for reliable detection of NO and NH₃, respectively. Hence, our findings indicate that gas-sensing applications can be significantly improved by utilizing a single-atom-doped ReSe₂ monolayer.