GROWTH MECHANISMS OF GOLD NANOSTRUCTURES*

Gold nanostructures with tetrahedral, hexagonal, icosahedral, decahedral, triangular, and star-decahedral shapes were synthesized in a single step using a polymer by heating HAuCl4-PVP (Polyvinylpyrrolidone) in EG (Ethylene Glycol) solution. In this process, PVP acted as a surfactant controlling the shape of the particles, and EG is a reducing agent obtaining truncated polyhedral particles with different sizes. We studied the growth mechanisms of five-fold nanoparticles and hollow hexagonal particles. The two possible layer-by-layer growth mechanisms are based on nucleation from a five-fold seed and successive growth through the twinning of a truncated tetrahedron. The structural features of the produced nanoparticles were characterized by electron microscopy. TEM, SEM, STEM, and EDS were performed.