High-Yield Seedless Synthesis of Triangular Gold Nanoplates through Oxidative Etching

• Published in: Nano letters 2014-12, Vol.14 (12), p.7201-7206
• Main Authors: Chen, Lei, Ji, Fei, Xu, Yong, He, Liu, Mi, Yifan, Bao, Feng, Sun, Baoquan, Zhang, Xiaohong, Zhang, Qiao
• Format: Article
• Language: English
• Subjects: Condensed matter: structure, mechanical and thermal properties; Cross-disciplinary physics: materials science; rheology; Etching; Exact sciences and technology; Formations; Gold; Iodides; Low-dimensional structures (superlattices, quantum well structures, multilayers): structure, and nonelectronic properties; Materials science; Nanocrystalline materials; Nanoscale materials and structures: fabrication and characterization; Nanostructure; Noble metals; Physics; Planar structures; Plasmons; Surfaces and interfaces; thin films and whiskers (structure and nonelectronic properties)
• ISSN: 1530-6984; 1530-6992
• DOI: 10.1021/nl504126u

We demonstrate that monodispersed triangular gold nanoplates with high morphological yield (>90%) can be synthesized through a rapid one-pot seedless growth process. The edge length of triangular Au nanoplates can be readily tuned between 40 and 120 nm by varying the reaction parameters. Systematic studies reveal that distinct from previous hypothesis that the formation of nanoplates is mainly determined by the selective binding of iodide ions, our results show that iodide ions could have dual functions: it can selectively bind to the Au {111} facets and also selectively remove other less stable shape impurities through oxidative etching by forming tri-iodide ions (I3 –), thus facilitating the formation of nuclei with dominant planar structure. This new synthetic route will not only help to better understand the growth mechanism of triangular gold nanoplates but also promote the research in anisotropic noble metal nanostructures.