Highly shape-selective synthesis of monodispersed fivefold twinned platinum nanodecahedrons and nanoicosahedrons

A general and facile solid liquid interface mediated reduction route towards highly shape-selective synthesis of monodispersed Pt nanodecahedrons (NDs) and nano-icosahedrons (NI) was demonstrated. The Pt NIs with a size of 12.6 nm and selectivity of 88% were bounded with twenty (111) facets. By altering the added amount of MGS from 1 to 10 mg, the optimum selectivity value is obtained at 5 mg. During prolonged growth, thermodynamically favored Pt NDs or NIs were yielded due to either the induction of residual Pt ions or the drive of total energy minimization. The formation of twined structures is found to be due to the contraction of surface Pt atoms of the nuclei driven by high levels of external stress generated from depositing an overlayer of the incompletely reduced (Pt) nanoclusters with strong Pt Pt interactions on the growing nuclei.