Nanostructural Transformations During Reactions of Metal Nanoparticles

摘要

Nanostructural transformations of metal nanoparticles driven by chemical reactions, such as the nanoscale Kirkendall effect, are useful for synthesizing complex nanostructures and for controlling their properties. Three studies of nanoparticle transformations will be presented: (1) In the synthesis of nickel phosphide nanoparticles, the P:Ni molar ratio of the reactants determines whether the nanoparticles have crystalline-hollow, crystalline-solid, or amorphous-solid nanostructures. (2) When Ni nanoparticles of different sizes are oxidized to NiO through the nanoscale Kirkendall effect, the resulting nanostructures strongly depend on the nanoparticle size. (3) Addition of Ag~+ t o Au nanoparticles during digestive ripening r e s u l t s i n Au(core)/Ag(shell) nanoparticles that convert to AuAg a l l o y nanoparticles upon annealing.