Theoretical study of the adsorption behaviors of gas molecules on the Au-functionalized MoS2 nanosheets: A search for highly efficient gas sensors

Abstract

Using the density functional theory calculations, we explored the electronic, and magnetic properties of Au and Pt adsorbed MoS2 systems. We examined the binding of some gas molecules (CO, CO2, NH3, NO, NO2, and O3) on these noble metal adsorbed structures. Stability analysis based on binding energy calculations indicate that both Au-adsorbed and Pt-adsorbed MoS2 monolayers are energetically stable and can be considered as a promising nanostructure media for gas sensing and capturing. The binding strength of gas molecules over the Au-adsorbed structures was found to be higher than that over the non-adsorbed systems, being attributed to their higher adsorption energies. Band structure calculations reveal a metallic characteristics for Au-adsorbed MoS2 systems, while Pt-adsorbed ones show semiconductor nature. The substantial overlaps of the local density of states of the Au atom and substrate’s interacting atoms are an indication of a covalent interaction and consequently chemisorption process at the interface.