A general phase-transfer protocol for metal ions and its application in nanocrystal synthesis. Nat. Mater. 8, 683

Institute of Bioengineering and Nanotechnology, 31 Biopolis Way, The Nanos, Singapore 138669, Singapore.
Nature Material (Impact Factor: 36.5). 08/2009; 8(8):683-9. DOI: 10.1038/nmat2490
Source: PubMed


Nanocrystals prepared in organic media can be easily self-assembled into close-packed hexagonal monolayers on solvent evaporation for various applications. However, they usually rely on the use of organometallic precursors that are soluble in organic solvents. Herein we report a general protocol to transfer metal ions from an aqueous solution to an organic medium, which involves mixing the aqueous solution of metal ions with an ethanolic solution of dodecylamine (DDA), and extracting the coordinating compounds formed between the metal ions and DDA into toluene. This approach could be applied towards transferring a wide variety of transition-metal ions with an efficiency of >95%, and enables the synthesis of a variety of metallic and semiconductor nanocrystals to be carried out in an organic medium using relatively inexpensive water-soluble metal salts as starting materials. This protocol could be easily extended to synthesize a variety of heterogeneous semiconductor/noble-metal hybrids and to nanocomposites with multiple functionalities.

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Available from: Edward H Sargent, Jun 12, 2015
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    • "Platinum (Pt) nanoparticles are catalytically active for the anodic reaction (methanol oxidation reaction, MOR) of the direct methanol fuel cell (DMFC)123. Hollowing platinum (Pt) nanoparticles with galvanic replacement or scarificial templates offers a promising approach to meet the high performance goals in electrocatalysis456789. For intance, Fan and co-workers developed a photocatalytic approach using densely packed optically active porpyrins to template the synthesis of well-defined hollow Pt nanostructures which were excellent catalyst for the methanol oxidation reaction (MOR)7. "
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    Scientific Reports 08/2014; 4:6204. DOI:10.1038/srep06204 · 5.58 Impact Factor
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    • "contained within each NC, these nanoscale materials are generally represented by an exact chemical formula: Au m (SR) n where m and n are the numbers of Au atoms and thiolate ligands respectively [9]. Unlike traditional nanocrystals [10] having a size within the length scale of 3–100 nm, NCs exhibits discrete electronic structure and molecular-like behaviour. However, the successful biological applications of these thiolated NCs will require a better understanding of the NCs parameters that can potentially impact biological interactions and functions. "
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    • "Finally, the as-prepared ternary Au@Ag2S-Pt nanocomposites were transferred from aqueous phase to toluene using an approach developed for the phase transfer of metal nanoparticles and ions3637. Phase transfer of the nanocomposites from aqueous phase to a non-polar organic medium was conducted since we experimentally found that the loading efficiency of the particles on XC-72C carbon supports from the organic medium (~99%) was much higher than that from the aqueous phase (~37%). "
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    ABSTRACT: Mastery over the structure of nanomaterials enables control of their properties to enhance their performance for a given application. Herein we demonstrate the design and fabrication of Pt-based nanomaterials with enhanced catalytic activity and superior selectivity toward the reactions in direct methanol fuel cells (DMFCs) upon the deep understanding of the mechanisms of these electrochemical reactions. In particular, the ternary Au@Ag2S-Pt nanocomposites display superior methanol oxidation reaction (MOR) selectivity due to the electronic coupling effect among different domains of the nanocomposites, while the cage-bell structured Pt-Ru nanoparticles exhibit excellent methanol tolerance for oxygen reduction reaction (ORR) at the cathode because of the differential diffusion of methanol and oxygen in the porous Ru shell of the cage-bell nanoparticles. The good catalytic selectivity of these Pt-based nanomaterials via structural construction enables a DMFC to be built without a proton exchange membrane between the fuel electrode and the oxygen electrode.
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