Coalescence of AuPd nanoalloys in implicit environments

Abstract

The optimal design of nanoparticles and nanoalloys arises from the control of their morphology which depends on the synthesis process they undergo. Coalescence is widely accepted as one of the most common synthetic mechanisms, and it occurs both in the liquid and gas phase. Coalescence is when two existing seeds collide and aggregate into a larger object. The resulting aggregate is expected to be far from the equilibrium isomer, i.e. the global minimum of the potential energy surface. While the coalescence of nanoparticles is well studied in the vacuum, sparse computational studies are available for the coalescence in an environment. By Molecular Dynamics simulations we study the coalescence of Au and Pd nanoseeds surrounded by an interacting environment. Comparing the initial stages of the coalescence in the vacuum and the presence of an interacting environment, we show that the kinetics of the formation process, strongly depends on the environment and on the size of the nanoalloy. Furthermore, we show that is possible to tune the resulting nanoalloys surface chemical composition by changing their surrounding environment.