First-principles study of molecule adsorption on Ni-decorated monolayer MoS_2

摘要

The interactions between four different gas molecules (methanol, o-xylene, p-xylene and m-xylene) and Ni-decorated monolayer MoS2 were investigated by means of density functional computations to exploit its potential application as a gas sensor. The electronic properties of the Ni-decorated monolayer MoS2 and gas molecule (adsorbent-adsorbate properties) strongly depend on the Ni-decorated monolayer MoS2 structure and the molecular configuration of the adsorbate. The adsorption properties of volatile organic compound (VOC) molecules on Ni-decorated MoS2 has been studied taking into account the parameters such as adsorption energy, energy bandgap, density of states, and Mulliken charge transfer. All three xylene isomers showed considerably stronger adsorption on the Ni-decorated monolayer MoS2 than the methanol. Among them, p-xylene was found to have the highest adsorption energy and charge transfer value in interaction with the Ni-decorated monolayer MoS2. The adsorption energy shows a significant improvement after nickel decoration for xylene adsorption. Therefore, the adsorption of xylene vapor on Ni-decorated monolayer MoS2 was found to be favorable comparing to other VOC molecules.