Department of Materials Science and Engineering, University of California, Los Angeles, 410 Westwood Plaza, Los Angeles, California 90095, USA.
Nanoscale. 2018 Feb 8;10(6):2764-2773. doi: 10.1039/c7nr07514f.
Assembling Au nanocrystals with tunable dimensions and shapes on graphene templates has attracted increasing attention recently. However, directly growing anisotropic Au nanobelts on a graphene support has been rarely reported. Here, a facile, one-pot, and surfactant-free route is demonstrated to synthesize well-defined Au nanobelts with the induction of a multilayer graphene (mlG) template. The obtained Au nanobelts are single-crystalline with a preferable (111) orientation. More importantly, their structural evolution starting from Au clusters is systematically investigated using scanning electron microscopy (SEM) and transmission electron microscopy (TEM). The results confirm that mlG consistently induces the growth of Au nanobelts from nucleation to the growth completion. The interfacial interaction between Au atoms and the graphene lattice is a predominant factor to direct the shapes and structures of Au nanocrystals, which makes the structures of Au nanobelts highly tunable with the surface modification of the mlG template. The assembly of mlG-Au nanobelts also presents extraordinary detection sensitivity when employed as a flexible surface-enhanced Raman scattering (SERS) substrate, suggesting their great potential application in high-performance sensors. This report strengthens the fundamental understanding of the interactions between noble metals and carbon interfaces, which paves the way to construct and manipulate the complex structures of metals on graphitic substrates.
在石墨烯模板上组装具有可调尺寸和形状的 Au 纳米晶体最近引起了越来越多的关注。然而，在石墨烯载体上直接生长各向异性的 Au 纳米带却很少有报道。本文报道了一种简便的、一锅法的、无表面活性剂的方法，在多层石墨烯（mlG）模板的诱导下合成具有良好定义的 Au 纳米带。所得到的 Au 纳米带为单晶，具有较好的（111）取向。更重要的是，使用扫描电子显微镜（SEM）和透射电子显微镜（TEM）系统地研究了它们从 Au 团簇开始的结构演变。结果证实，mlG 始终从成核到生长完成诱导 Au 纳米带的生长。Au 原子与石墨烯晶格之间的界面相互作用是指导 Au 纳米晶体形状和结构的主要因素，这使得 Au 纳米带的结构可以通过 mlG 模板的表面修饰进行高度调节。作为一种柔性表面增强拉曼散射（SERS）基底，mlG-Au 纳米带的组装也表现出非凡的检测灵敏度，这表明它们在高性能传感器中有很大的应用潜力。本报告加强了对贵金属与碳界面之间相互作用的基本理解，为在石墨基底上构建和操纵金属的复杂结构铺平了道路。
