Heterogeneous Nucleation Mechanism of Potassium Iodide on Graphene Surface in Water

In this work, molecular dynamic (MD) simulations are applied to investigate the heterogeneous nucleation mechanism of KI on a graphene surface in water. As graphene is immersed in water, it mainly affects the structure of interfacial water (the topmost water layer at the interface between the substance and water). To maximize the hydrogen bonding of water, the dissolved solutes tend to accumulate to form the aggregate at the graphene surface, which undoubtedly affects the nucleation pathways of solutes in water. In comparison with homogeneous nucleation, a lower barrier may be expected during the heterogeneous nucleation of KI on a graphene surface in water. Therefore, as the graphene is immersed in water, this facilitates solute nucleation. From this work, it may be derived that heterogeneous nucleation may be closely related to the geometric characteristics of foreign surfaces, especially their geometric shape.