Controllable synthesis of multiple shapes of gold nanostructures

Abstract

In this work, we present a simple one-step method to synthesize various gold nanostructures (microplates, nanowires and nanowire networks) with the high yield using cinnamic acid (CA, C9H8O2) as reducing and capping agent through a thermal process. In this reaction system, by adjusting the concentration of CA from a high level to low level, the shape of the products was found to change from nanoparticles/microplates to two-dimensional nanowire networks/branched nanowires, ultimately to one-dimensional nanowires. Additionally, the size of the products increased with the increase in the concentration of HAuCl4 in the reaction system. The shape of the products was also strongly dependent on the pH of the reaction solution. By controlling the reaction time, the possible mechanism about the formation of different shape gold nanostructures was deduced.K e y w o r d s : metal, nanostructure, crystal growth, TEM

Controlled spontaneous generation of gold nanoparticles assisted by dual reducing and capping agents

“…Interesting findings were notably obtained with tannic acid [113,114], ascorbic acid [115], ascorbic-acid-based amphiphiles [116], gallic acid [117], 2-mercaptosuccinic acid [118,119], lactic acid [120], cinnamic acid [121], and the synthetic antibiotic ciprofloxacin (1-cyclopropyl-6-fluoro-1,4-dihydro-4-oxo-7-piperazinylquinolone-3-carboxylic acid) [122]. The main interest of these weak organic acids compared with some other reducing agents relies on the fact that Au-NPs can be synthesized at neutral pH and at room temperature.…”