Ag, Au, Pt, and Au-Pt nanoclusters in [N1114][C1SO3] ionic liquid: A molecular dynamics study

Abstract

A comprehensive study of the solvation of nanoclusters in ionic liquids (ILs) can provide essential understanding needed for the development of various applications of materials based on such systems, such as solar cells, lithium batteries, and nanocluster synthesis. In this work, the solvation of (Au)147, (Pt)147, (Ag)147, (Au-Pt)147, and (Au-Pt)309 clusters in the ionic liquid 1-butyl-1,1,1-trimethylammonium methane sulfonate [N1114][C1SO3] at 300, 500, and 700 K at atmospheric pressure was studied using molecular dynamics simulations. In addition, some thermodynamic, structural, and dynamic properties of ILs and different metal clusters at different temperatures were investigated. Our results showed that the Pt and Au-Pt systems have higher solvation energies than the rest of the systems. The solvation energy of different clusters decreased by increasing the temperature and increased by increasing the size of nanocluster. There was not significant change in the structure of the nanoclusters in the IL at different temperatures. However, the structures become more spherical at highest temperature. The core–shell structure of (Au-Pt)309 nanocluster did not change in IL even at higher temperatures. Our results also indicated that the anions are in closer distances to the nanocluster surfaces than the cations which is in an agreement with the DLVO theory. The charge separation is not complete in the IL because we cannot observe the individual anions and cations shells around the nanoclusters. Our dynamics results also showed that the silver atoms show higher self-diffusion values and the Pt atoms show lower self-diffusion values than the other metals.