Growth and galvanic replacement of silver nanocubes in organic mediaElectronic supplementary information (ESI) available. TEM and HRTEM of Ag nanocubes obtained with 0.44 mol DCB; HRTEM of Ag NPs formed after 1 h of reaction; fraction of twinned vs. single crystalline Ag NPs at different reaction times; TEM images of Ag NPs obtained under an inert atmosphere; TEM image of Ag NPs obtained with 3 mmol and 12 mmol oleylamine; extinction spectra and TEM images of Ag NPs obtained in different solvent

• Main Authors: Polavarapu, Lakshminarayana, Liz-Marzn, Luis M
• Format: Journal Article
• Language: English
• Published: 03.05.2013
• ISSN: 2040-3364; 2040-3372
• DOI: 10.1039/c3nr01244a

Although metal nanoparticles with various shapes can be prepared in polar organic solvents, little has been advanced toward the shape-controlled synthesis in non-polar solvents. We report a simple method for the synthesis of nearly monodisperse single crystalline silver nanocubes in a non-polar solvent (1,2-dichlorobenzene) by using oleylamine as both a reducing and capping agent. Mechanistic studies based on the time evolution of Ag nanoparticles revealed that multiply twinned nanocrystals form at the beginning of the reaction, which are gradually transformed into single crystalline Ag nanocubes by oxidative etching. Control experiments showed that the solvent plays an important role in the formation of such single crystalline Ag nanocubes. The effects of reaction temperature, oleylamine concentration, solvent, and the nature of the silver ion precursor on the morphology and monodispersity of the nanoparticles were systematically investigated. Additionally, the galvanic replacement reaction with HAuCl 4 in an organic medium was implemented to prepare hydrophobic hollow AuAg nanocages with tunable localized surface plasmon resonances. A simple method is reported for the synthesis of hydrophobic silver nanocubes and their transformation into nanocages and nanoframes in non-polar solvents.