Reduction Rate of Metal Precursors

Generally, when the reduction rate is slow, the nucleation and growth stage will be near equihbrium, and when the reduction rate is sped up, the near-equihbrium state will be broken. Near-equilibrium nucleation and growth lead to multi-twinned [39] and phase-separated BMNCs [42], while BMNCs with branched [38,43] or thermodynamically unstable morphologies [44] can be obtained under conditions far from the equilibrium regime. 

Nucleation under near-equilibrium conditions favors the formation of fivefold twinned metallic NCs when the (111) facets are stabilized [45]. Neglecting the edge and comer energy, the total free energy of a metallic NC can be written as  

If the reduction rate is high enough to keep the monomer concentration higher than supersaturation, as described by LaMer s model, numerous tiny nuclei will form and few monomers will be left for further growth. These liny nuclei tend to 

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