Spontaneous Formation of Heterodimer Au–Fe7S8 Nanoplatelets by a Seeded Growth Approach

Hybrid nanomaterials offer increased flexibility to achieve heterostructures with controlled functionalities and predictable linkages owing to their synergistic interactions. Here, we have developed a synthetic strategy that produced hexagonal-shaped nanoplatelets (NPLs) of gold–pyrrhotite (Au–Fe7S8) with Au embedded inside them by means of a seeded growth method. Using thiol-capped Au nanoparticles (NPs) as a seed, heterogeneous nucleation of the iron precursor was facilitated, leading to the formation of Au–Fe7S8 NPLs. The injection temperature and surface ligand of the seed (Au) were two critical factors that determined the homogeneity and final morphology of the Au–Fe7S8 NPLs. This strategy was further expanded using Ag NPs as the seed to construct heterodimers, producing Ag2S–Fe7S8 heterostructures.