Ligands as Matchmakers: Alloying from a Physical Mixture of Metal Nanoparticle Dispersions by Digestive Ripening

Digestive ripening (DR) of a physical mixture of different metal nanoparticles (NPs) in the presence of a suitable ligand is demonstrated to be a convenient way to obtain alloy NPs. The results show that the right choice of metal-ligand combination is extremely important for efficient alloying. The results are rationalized on the basis of hard soft acid base principles, and it is concluded that better alloying ensues if DR is carried out with soft ligands when soft metals are being used and hard ligands facilitate alloying between hard metals. On the other hand, when a physical mixture of hard-soft metals is taken, ligands with intermediate character work better. The results presented here could prove to be extremely valuable and open new avenues of making interesting alloy/intermetallic systems.

Automated summary

This study demonstrates that digestive ripening of a physical mixture of different metal nanoparticles in the presence of a suitable ligand is a convenient method to obtain alloy nanoparticles. The choice of metal-ligand combination is crucial for efficient alloying, with the use of soft ligands for soft metals and hard ligands for hard metals resulting in better alloying. Intermediate character ligands work better for a physical mixture of hard-soft metals. These results could be extremely valuable and lead to new opportunities for creating interesting alloy/intermetallic systems.