Molecular-Level Understanding of Continuous Growth from Iron-Oxo Clusters to Iron Oxide Nanoparticles

The formation of inorganic nanoparticles has been understood based on the classical crystallization theory described by a burst of nucleation, where surface energy is known to play a critical role, and a diffusion-controlled growth process. However, this nucleation and growth model may not be universally applicable to the entire nanoparticle systems because different precursors and surface ligands are used during their synthesis. Their intrinsic chemical reactivity can lead to a formation pathway that deviates from a classical nucleation and growth model. The formation of metal oxide nanoparticles is one such case because of several distinct chemical aspects during their synthesis. Typical carboxylate surface ligands, which are often employed in the synthesis of oxide nanoparticles, tend to continuously remain on the surface of the nanoparticles throughout the growth process. They can also act as an oxygen source during the growth of metal oxide nanoparticles. Carboxylates are prone to chemical reactions ...