On the polyol synthesis of silver nanostructures: glycolaldehyde as a reducing agent.
The polyol synthesis is a popular method of preparing metal nanostructures, yet the mechanism by which metal ions are reduced is poorly understood. Using a spectrophotometric method, we show, for the first time, that heating ethylene glycol (EG) in air results in its oxidation to glycolaldehyde (GA), a reductant capable of reducing most noble metal ions. The dependence of reducing power on temperature for EG can be explained by this temperature-dependent oxidation, and the factors influencing GA production can have a profound impact on the nucleation and growth kinetics. These new findings provide critical insight into how the polyol synthesis can be used to generate metal nanostructures with well-controlled shapes. For example, with the primary reductant identified, it becomes possible to evaluate and understand its explicit role in generating nanostructures of a specific shape to the exclusion of others.
Department of Chemistry, University of Washington, Seattle, Washington 98195, USA.
Sara E
SE
Skrabalak
Benjamin J
BJ
Wiley
Munho
M
Kim
Eric V
EV
Formo
Younan
Y
Xia
D000079:Acetaldehyde / Q000031:analogs & derivatives* / Q000737:chemistry; D008855:Microscopy, Electron, Scanning; D049329:Nanostructures / Q000737:chemistry* / Q000648:ultrastructure; D010084:Oxidation-Reduction; D011108:Polymers / Q000138:chemical synthesis* / Q000737:chemistry; D012834:Silver / Q000737:chemistry*; D013053:Spectrophotometry
D011108:Polymers; C024617:polyol; D012834:Silver; D000079:Acetaldehyde; C010972:glycolaldehyde