DFT study of gas adsorption and sensing based on noble metal (Ag, Au and Pt) functionalized boron selenide nanosheets

Abstract

Adsorption of transition metal atoms on the surface of 2D layered nanomaterials plays a significant role in modulating the electronic properties of the metal functionalized systems. In this work, we examined the adsorption of Ag, Au and Pt adatoms on the surface of BSe monolayer based on the DFT method. Our band structure calculations reveal that perfect BSe monolayer displays indirect gap semiconductor property. The adsorption performance of the Au-adsorbed BSe monolayer upon NO, NH3 and NO2 gas molecules was examined to evaluate its potential use for highly efficient gas sensor devices. The Au adatom is adsorbed on the BSe monolayer with considerable adsorption energy, which indicates the strength and stability of the substrate for adsorption processes. Thus, the Au-adsorbed BSe monolayer behaves as an excellent adsorbent for sensing NO, NH3 and NO2 gas molecules. Interestingly, all the gas molecules are strongly chemisorbed on the Au site of Au–BSe system. NO2 molecule presents the most favorable adsorption on the surface with oxygen atoms coordinated to the Au atom. Our results also suggest that gas molecules adsorption on the Au–BSe monolayer can lead to remarkable variations in the electronic properties of the systems. The greatly enhanced electron overlaps between the projected density of states of the interacting atoms confirm the chemical interaction between the gas molecules and Au–BSe monolayer.