Controlling the composition and elemental distribution of bi- and multi-metallic nanocrystals via dropwise addition

Colloidal synthesis of metal nanocrystals often relies on using reduction kinetics to manipulate their size, shape, internal structure and composition. Whereas the first three features can all be readily manipulated, it remains challenging to control the composition of nanocrystals because the reduction rate, and thus the production rate of atoms, follows an exponential decay during the synthesis. By stabilizing the reduction rate of a precursor in the steady state, dropwise addition has emerged as a transformative route for the colloidal synthesis of nanocrystals. This Perspective highlights the advantages of dropwise addition over traditional one-shot injection for controlling the composition and elemental distribution of bi- and multi-metallic nanocrystals. Our analysis demonstrates the promise of dropwise addition for achieving the deterministic synthesis of complex nanocrystals with controlled compositions for a range of applications, especially those related to catalysis and energy conversion. By stabilizing the reduction rate of a precursor in the steady state, dropwise addition has emerged as a transformative route for the colloidal synthesis of nanocrystals. This Perspective highlights the advantages of dropwise addition over one-shot injection for controlling the composition and elemental distribution of bi- and multi-metallic nanocrystals.