Determination of Accurate Interaction Parameters between the Molybdenum Disulfide and Water to Investigate Their Interfacial Properties

Molybdenum disulfide (MoS2), due to its many potential applications such as energy storage material, sensor, and lubricant, has attracted much attention from the scientific community. However, the environmental conditions like temperature, pressure, and, especially, humidity affect the performance of MoS2. Therefore, understanding the structure of water at the MoS2–water interface is critical to improve and design novel MoS2-based devices. In this study, we develop precise nonbonded interactions between MoS2 represented by the Stillinger–Weber (SW) potential and three water models to reproduce its experimental macroscopic contact angle and the binding energies of water molecules obtained from quantum calculations. The force-field (FF) parameter development was accelerated by integrating particle swarm optimization (PSO) algorithm with molecular dynamics (MD) simulations. Our systematic approach to develop these intermolecular potentials enabled us to reproduce the macroscopic contact angle of ∼63°–70°, which was in good agreement with experimental contact angles reported in the literature. Additionally, the structural properties of water such as z-density profile, orientation of O–H bonds near the MoS2 surface, and hydrogen-bond distribution in different regions of a droplet were studied to gain the molecular level insights of the MoS2–water interface. This study not only provides a novel hybrid approach that integrated experimental and quantum calculations data to develop accurate FF parameters to study wettability of surfaces but also sheds a new light on structure of water at the MoS2–water interface.