Pristine and transition metal decorated holey graphyne monolayer as an ammonia sensor: insights from DFT simulations

Abstract

The first-principles density functional theory method has been employed to comprehensively investigate adsorption configurations, adsorption energies, electronic properties, and gas sensing characteristics of pure and transition metal (TM = Sc, Pd, and Cu) decorated holey graphyne (HGY) monolayer for the detection of ammonia (NH3). The calculations reveal that the NH3 molecule weakly interacts with the pristine HGY surface with an adsorption energy of −0.146 eV. The expedited charge transfer and strong orbital hybridization between the NH3 molecule and the decorated TM (except Pd) resulted in the strong adsorption of the NH3 on the TM-decorated system. Among the three metals, it is found that the Sc decorated HGY can be regarded as the potential NH3 sensor owing to its reasonable adsorption energy of −1.49 eV, a large charge transfer of 0.113e, and an attainable recovery time of 3.2 s at 600 K. Furthermore, the stability of the Sc decorated HGY structure at ambient temperature is also validated using the ab initio molecular dynamic simulations. The results of the current study mirror the probable application of 2D HGY-based gas sensors for the detection of ammonia.