Center for Nanoscale Materials, Nanoscience and Technology Division, Argonne National Laboratory, Argonne, IL 60439, USA.
Nanoscale. 2016 Oct 6;8(39):17250-17255. doi: 10.1039/c6nr05167g.
Fractals are commonly observed in nature and elucidating the mechanisms of fractal-related growth is a compelling issue for both fundamental science and technology. Here we report an in situ electron microscopy study of dynamic fractal growth of platinum during electrodeposition in a miniaturized electrochemical cell at varying growth conditions. Highly dendritic growth - either dense branching or ramified islands - are formed at the solid-electrolyte interface. We show how the diffusion length of ions in the electrolyte influences morphology selection and how instability induced by initial surface roughness, combined with local enhancement of electric field, gives rise to non-uniform branched deposition as a result of nucleation/growth at preferred locations. Comparing the growth behavior under these different conditions provides new insight into the fundamental mechanisms of platinum nucleation.
分形在自然界中很常见，阐明与分形相关的生长机制是基础科学和技术领域的一个重要问题。在这里，我们报告了在微型电化学池中的电沉积过程中，铂的动态分形生长的原位电子显微镜研究，研究了不同的生长条件。在固-液界面处形成了高度枝状的生长-密集的分支或分叉的岛屿。我们展示了电解质中离子的扩散长度如何影响形态选择，以及初始表面粗糙度引起的不稳定性，结合电场的局部增强，如何导致由于优先位置的成核/生长而导致非均匀的分支沉积。比较这些不同条件下的生长行为为深入了解铂成核的基本机制提供了新的认识。
