Wettability and friction of water on a MoS₂ nanosheet

Abstract

The molybdenum disulfide (MoS2) nanosheet is a promising two-dimensional (2D) material and has recently been used in biological sensing. While the electronic structure of 2D MoS2 sheet has been actively studied, the role of its atomic structure and thus the interfacial interactions with bio-fluids are still elusive. Using Molecular dynamics simulations, we developed MoS2 force field parameters to reproduce the experimentally determined water contact angle of the MoS2 nanosheet and then predicted the slip-length of water that has not been measured in experiment yet. Simulation results suggest that the MoS2 nanosheet is a hydrophobic and low-friction surface, despite its seemingly significant charges of surface atoms and relatively strong strength of van der Waals potentials. We expect that the developed force fields for depicting surface atoms of MoS2 will facilitate future research in understanding biomolecule-MoS2 interactions in MoS2-based biosensors.