Feng Yuhua, Wang Yawen, Song Xiaohui, Xing Shuangxi, Chen Hongyu
Division of Chemistry and Biological Chemistry , School of Physical and Mathematical Sciences , Nanyang Technological University , Singapore 637371.
Faculty of Chemistry , Northeast Normal University , Changchun 130024 , P. R. China . Email:
Chem Sci. 2017 Jan 1;8(1):430-436. doi: 10.1039/c6sc02276f. Epub 2016 Aug 17.
We report multi-site nucleation and growth of Ag islands on colloidal Au nanoparticles. By modifying a single factor, a range of products from Janus nanoparticles to satellite nanostructures are obtained. The identification of these key factors reveals the correlation between the concentration gradient and the choice of nucleation sites. In contrast to the inhibited homogeneous nucleation in the bulk solution, we argue that the non-steady-state concentration gradient plays a critical role in inhibiting nucleation within nanometer distance during the initial stage of growth-an essential but not yet recognized factor in colloidal synthesis. A depletion sphere model was developed, so that the multi-site nucleation is well integrated with the classic theory of nucleation and growth. Alternative explanations are carefully examined and ruled out. We believe that the synthetic know-how and the mechanistic insights can be broadly applied and are of importance to the advance of nanosynthesis.
我们报道了在胶体金纳米颗粒上银岛的多部位成核与生长。通过改变单一因素，可获得从Janus纳米颗粒到卫星纳米结构的一系列产物。对这些关键因素的识别揭示了浓度梯度与成核位点选择之间的相关性。与本体溶液中受抑制的均相成核不同，我们认为非稳态浓度梯度在生长初期抑制纳米距离内的成核过程中起着关键作用，这是胶体合成中一个重要但尚未被认识到的因素。我们建立了一个耗尽球模型，使多部位成核与经典的成核和生长理论很好地结合起来。仔细研究并排除了其他解释。我们相信，这些合成技术和机理见解能够得到广泛应用，对纳米合成的进展具有重要意义。
