Shape Transformation of Gold Nanoparticles from Octahedron to Cube Depending on in situ Seed-Growth Time

In this study, we report on the observation that the particleshape was dependent upon in situ seed-growth time of ourone pot synthesis of gold nanoparticles. It was found that thecube yield increased with the increase of the seed-growthtime while a short seed-growth time (~15 min) resulted inthe formation of high-yield octahedral particles. This canalso be regarded as a simple and convenient method ofsynthesizing octahedral and cubic gold nanoparticles inaqueous solution. Although the synthetic methods usingcetyltrimethylammonium bromide (CTAB) and ascorbicacid have been previously reported, the shape control of goldnanoparticles relied on the adjustment of the concentrationof reducing agent, gold precursor, activators, or seed parti-cles. In this report, shape of gold nanoparticles was con-trolled by tuning only one parameter, the in situ seed-growthtime, without any variation in reactant concentrations or inthe way of a separate seeding.Typically, a 250 μL of 10 mM HAuCl