Facile Synthesis of Stable Subnanosized Silver Clusters in Microemulsions

Abstract

Island clusters: By using kinetic control, stable Agn clusters (n≤10) are synthesized in microemulsions. Nanoislands composed of the subnanosized clusters can be deposited onto a substrate (see picture). The clusters are characterized by a variety of methods, including scanning tunneling microscopy (STM), mass spectrometry, UV/Vis spectroscopy, and differential pulse voltammetry.

Water‐Soluble Fluorescent Silver Nanoclusters

“…[33] Ag n nanoclusters (n < 10) were also obtained in microemulsions using NaH 2 PO 2 Á H 2 O as a mild reducing agent in a kineticallycontrolled manner. [34] …”

Exceptional oxidation activity with size-controlled supported gold clusters of low atomicity

“…25 While it appears that in order to control reactivity, the atomicity control of the gold clusters is crucial, the synthesis of size-selected metal clusters and their deposition over a solid support is a challenging task. 26 The wet-chemistry methods for preparing supported metal clusters involve the anchoring of well defined precursors to an adequate support, 27,28 followed by removal of the ligands by post-synthesis treatments, trying to prevent cluster agglomeration during these steps. 9, [29][30][31]32 Soft landing of monodisperse metal clusters grown in the gas phase and with precise size selection by mass spectrometry is a more straightforward method, but it requires sophisticated equipment, and the scaling up of the process is a major drawback.…”

Metallic Clusters: Theoretical Background, Properties and Synthesis in Microemulsions

“…The reaction was studied at room temperature through a period of six weeks. After a few days, the color of the microemulsion changed, and new bands were observed in the absorption spectra, at 250-270 (nm) and 400-450 (nm), associated with the formation of small Ag clusters (with n < 10) with planar geometries, whose presence was confirmed by STM [41]. After approximately four weeks, the sample became colorless, and a new band appeared at 287 (nm) associated with the formation of tridimensional geometries.…”

“…The absence of a plasmonic band has also been observed for Ag clusters prepared in AOT microemulsions by the addition of a mild reducing agent (sodium hypophosphite) [40,41]. The reaction was studied at room temperature through a period of six weeks.…”