Comparison of the Stability of 2H Nanosurfaces by the Adsorption of Small Molecules : A DFT Study

Abstract

Density functional theory (DFT) calculations were carried out to understand the structural stability of 2D nanosheets of gold and silver in hexagonal phase of 2H by the adsorption of small molecules. In this work, we have obtained the bonding and adsorption properties of such small molecules as H2O, H2O2, and C2H5OH on 2H phase of gold and silver nanosurfaces, through DFT method using Quantum Expresso (QE) code. The high absorption energy values of (-2.45 eV, -2,46 eV, -2, 41 eV) for H2O, H2O2, and C2H5OH molecules on 2H-Au surfaces, respectively obtained than that of 2H-silver surfaces that the interaction between small molecules and both 2H nanosurfaces corresponds to physisorption. However, during the adsorption, the gold surface in the 2H phase (2H-Au) seems to preserve its atomic structure, while 2H-Ag surface changes from 2H to the fcc structure. Based on the analysis of electronic and physicochemical properties, the composite systems of 2H-gold/2H-silver-small molecules exhibit semiconductor behaviour. While 2H-Ag surfaces have short recovery time values for hydrogen peroxide (H2O2), this time is quite long for 2H-Au surfaces. Because of the long recovery time, Au-2H reported surfaces can be a candidate for possible applications of viral capture. Thus, the reported results are significant, and they would stimulate the experimental and further studies.