The Wallace H. Coulter Department of Biomedical Engineering, Georgia Institute of Technology , Atlanta, Georgia 30332, United States.
Nano Lett. 2015 Feb 11;15(2):1445-50. doi: 10.1021/acs.nanolett.5b00158. Epub 2015 Jan 30.
Kinetic control is a powerful means for maneuvering the twin structure and shape of metal nanocrystals and thus optimizing their performance in a variety of applications. However, there is only a vague understanding of the explicit roles played by reaction kinetics due to the lack of quantitative information about the kinetic parameters. With Pd as an example, here we demonstrate that kinetic parameters, including rate constant and activation energy, can be derived from spectroscopic measurements and then used to calculate the initial reduction rate and further have this parameter quantitatively correlated with the twin structure of a seed and nanocrystal. On a quantitative basis, we were able to determine the ranges of initial reduction rates required for the formation of nanocrystals with a specific twin structure, including single-crystal, multiply twinned, and stacking fault-lined. This work represents a major step forward toward the deterministic syntheses of colloidal noble-metal nanocrystals with specific twin structures and shapes.
动力学控制是操纵孪晶结构和形状的金属纳米晶体的有力手段，从而优化它们在各种应用中的性能。然而，由于缺乏关于动力学参数的定量信息，对于反应动力学所起的明确作用只有模糊的理解。以 Pd 为例，在这里我们证明了动力学参数，包括速率常数和活化能，可以从光谱测量中得出，然后用于计算初始还原速率，并进一步将该参数与种子和纳米晶体的孪晶结构定量相关联。在定量的基础上，我们能够确定形成具有特定孪晶结构（包括单晶、多孪晶和堆垛层错线）的纳米晶体所需的初始还原速率范围。这项工作朝着具有特定孪晶结构和形状的胶体贵金属纳米晶体的确定性合成迈出了重要的一步。
