Formation of Highly Thin, Electron-Transparent Gold Nanoplates from Nanoseeds in Ternary Mixtures of Cetyltrimethylammonium Bromide, Poly(vinyl pyrrolidone), and Poly(ethylene glycol)

Abstract

A simple approach to grow highly thin and electron-transparent gold nanoplates with a micrometer range edge-length dimension is demonstrated. The thin nanoplates were obtained by realizing an effective two-dimensional (2D) crystal growth of the nanoseed in a ternary surfactant mixture of cetyltrimethylammonium bromide (CTAB), poly (vinyl pyrrolidone) (PVP), and poly (ethylene glycol) (PEG). By simply controlling the concentration ratio of these three surfactants in the growth solution, high yield triangular and hexagonal nanoplates with thicknesses as low as ca. < 5 nm and edge-length dimensions extended up to ca. 1 μm could be realized. It was found that PVP and PEG play a unique combinative function in the projection of effective 2D crystal growth of the nanoseed probably via effective selective adhesion on the nanocrystals plane. Owing to their special characteristics, the highly thin gold nanoplates should find extensive use in catalysis, nanoelectronics, and surface-enhanced Raman spectroscopy (SERS)...