TEM and HRTEM Evidence for the Role of Ligands in the Formation of Shape-Controlled Platinum Nanoparticles

The morphology of platinum nanoparticles synthesized using an organometallic approach from PtMe2(C8H12) is influenced by the nature of the ligands used as stabilizing agents. The use of long alkyl chain amines leads to the formation of multipodal nanoparticles that transform into compact nano-objects, adopting cubic, truncated cubic, or cuboctahedral shapes. In contrast, the use of diamine ligands allows the growth of compact (111) arrowlike faces, forming polycrystalline nanoparticles of an overall desert-rose aspect. Different reaction parameters are studied ([ligand]/[metal] ratio, temperature, solvent identity) in order to optimize the various shapes.