Feasible synthesis of etched gold nanoplates with catalytic activity and SERS properties

Etched gold nanoplates have been successfully synthesized through a simple and green hydrothermal reaction, which was conducted in the presence of dextran at 130 degrees C for 24h. Scanning and transmission electron microscopy (SEM and TEM) demonstrated that the as-synthesized products are generally etched nanoplates and the electron diffraction (ED) pattern clearly showed that they are highly [111] oriented with a hexagonal nature. X-ray diffraction measurements indicated that the etched gold nanoplates are a pure face-centered cubic (fcc) phase with a preferred orientation in the < 111 > direction. Energy-dispersive X-ray spectroscopy (EDS) revealed that the product is only composed of elemental gold. The influences of the reaction parameters have been studied and it was found that the concentrations of dextran and HAuCl4, as well as the reaction temperature, play important roles in the control of morphology in the products. In addition, the formation mechanism of the etched gold nanoplates has also been revealed. The etched gold nanoplates could catalyze the reduction of 2-nitroaniline quite effectively and the reproducibility of the surface enhanced Raman spectrum (SERS) property of Rhodamine 6G on the etched gold nanoplates has also been investigated.