Growth mechanisms of silver nanoparticles: a molecular dynamics study

The shape control of metal nanoparticles allows one to finely tune their properties with great versatility. A self-seeding coreduction method has recently been developed for the synthesis of silver nanodiscs, triangular nanoplates and nanospheres. The addition of surfactants was found to be one of the most important factors in determining the final particle shape. In this paper, molecular dynamics simulations are performed to understand the growth mechanisms of silver nanoparticles for different surfactants (i.e. bis(2-ethylhexyl) sulfosuccinate, 1-dodecanethiol and cetyltrimethyl ammonium). The interaction energies between the surfactants and the silver crystal plane (i.e. (100), (110), (111)) are calculated. The molecular structural property of surfactants at the silver surface is also examined. It is demonstrated that the calculated interaction energies explain well the growth behaviour observed in the silver nanoparticle systems. Molecular dynamics simulation could provide a theoretical guideline for the choice of surfactants and hence the synthesis of various metal nanoparticles with controlled shape.