Facile Synthesis of Platinum Right Bipyramids by Separating and Controlling the Nucleation Step in a Continuous Flow System
Facile Synthesis of Platinum Right Bipyramids by Separating and Controlling the Nucleation Step in a Continuous Flow System
复制标题
通过在连续流系统中分离和控制成核步骤轻松合成铂直位双锥体
DOI：
10.1002/chem.202101988
复制
发表时间：
2021
期刊：
影响因子：
--
通讯作者：
Xia, Younan
中科院分区：
文献类型：
--
作者：
Chen, Ruhui;Shi, Yifeng;Xie, Minghao;Xia, Younan
胶体合成具有可控形状和内部结构的金属纳米晶体需要严格控制成核和生长过程。在这里，我们报告了一种通过分离成核与生长并控制连续流动反应器中的成核步骤来简便合成Pt右双锥（RBP）的方法。具体地，通过将反应溶液引入保持在升高的温度下的管式流动反应器中以产生单孪晶种来热触发均质成核。在较低的温度下，保护单孪晶晶种免受氧化蚀刻，以允许它们缓慢生长并演变成RBP，同时可以在很大程度上抑制不需要的晶种的额外成核，以确保RBP作为主要产物。进一步的研究表明，种子的内部结构和生长模式分别由用于成核和生长步骤的温度决定。参与合成的Br−离子也在RBP的生成中发挥了关键作用，它作为Pt{100}面的封端剂，同时通过与Pt（IV）离子配位来调节还原动力学。
Colloidal synthesis of metal nanocrystals with controlled shapes and internal structures calls for a tight control over both the nucleation and growth processes. Here we report a method for the facile synthesis of Pt right bipyramids (RBPs) by separating nucleation from growth and controlling the nucleation step in a continuous flow reactor. Specifically, homogeneous nucleation was thermally triggered by introducing the reaction solution into a tubular flow reactor held at an elevated temperature to generate singly‐twinned seeds. At a lower temperature, the singly‐twinned seeds were protected from oxidative etching to allow their slow growth and evolution into RBPs while additional nucleation of undesired seeds could be largely suppressed to ensure RBPs as the main product. Further investigation indicated that the internal structure and growth pattern of the seeds were determined by the temperatures used for the nucleation and growth steps, respectively. The Br−ions involved in the synthesis also played a critical role in the generation of RBPs by serving as a capping agent for the Pt{100} facets while regulating the reduction kinetics through coordination with the Pt(IV) ions.