Synthesis of Palladium Nanoscale Octahedra through a One‐Pot, Dual‐Reductant Route and Kinetic Analysis

Shape‐controlled synthesis of colloidal metal nanocrystals has traditionally relied on the use of an approach that involves the reduction of a metal precursor by a single reductant. Once the concentration of atoms surpasses supersaturation, they will undergo homogeneous nucleation to generate nuclei and then seeds, followed by further growth into nanocrystals. In general, it is a grand challenge to optimize such an approach because the kinetic requirement for nucleation tends to be drastically different from what is needed to guide the growth process. In this work, we overcome this difficulty by switching to a dual‐reductant approach, in which both strong and weak reductants are added into the same reaction solution. By controlling their amounts to program the reduction kinetics, the strong reductant only regulates the homogeneous nucleation process to generate the desired seeds, and once consumed, the weak reductant takes over to control the growth pattern and thereby the shape of the resulting nanocrystals. Separation agreement: A strategy for effectively separating the growth of nanocrystals from the nucleation step in a one‐pot setting is presented. The use of a combination of strong and weak reductants in the right proportion manipulates the reduction profile of the reaction to ensure the formation of single‐crystal seeds and then Pd octahedral nanocrystals.