Shape Control of Produced Nanoparticles

Shape control is commonly achieved through a two-step process, termed “SEED MEDIATED GROWTH”. At first step the product is uniform spherical seed particles.  These spherical seed particles are composed of densely packed atom with different facets and surface boundaries. Some facets or surface boundaries are energetically stable due to directional considerations or because organic molecules are adsorbed on their surface as shown in next figure. 

In second step the more metal ions are added to specific unstable places on the nanoparticle surfaces, this resulting in larger particles of particular morphology. The reason for the second stage in this method is that facets are less energetically stable and they continue “growing” and “adding” new atoms.