Abstract: Classical molecular dynamics simulations were employed to investigate the structural and dynamical properties of water near an Au nanoparticle at roomtemperature. The simulation results showed that a well-defined multi-layered structure of water was formed close to the surface of the Au nanoparticle and the orientation of water molecules in the interfacial region changed gradually fromthe random arrangement to the ordered arrangement with the reduction in the radial distance. By analyzing the mean square displacement and occupation time distribution in different water layers, we found that water molecules in the first and second layers display very low diffusivity, whereas water molecules in the third and fourth layers could migrate fromthe interfacial region to the bulk region at short time. Additionally, the average number of hydrogen bonds per water molecule in the interfacial region was higher than that in the bulk phase.

Key words: Nanoparticle, Water, Molecular dynamics, Structure, Diffusion, Hydrogen bond