Shape Control of Platinum Nanoparticles

Authors


  • The authors are very grateful to V. Collière and L. Datas from the “Service Commun de Microscopie Electronique de L'Université Paul Sabatier” (TEMSCAN) for TEM/HRTEM, M.-J. Casanove from CEMES for TEM-FEG. E. R. thanks the program CONACyT-SFERE for a grant (N°161295). This research was supported by the Centre national de la Recherche Scientifique, CNRS. Supporting Information is available online from Wiley InterScience or from the authors.

Abstract

The synthesis of shape controlled platinum nanoparticles has been investigated through an organometallic approach starting from the complex Pt2(dba)3 and using a long alkyl chain amine, hexadecylamine (HDA), as stabilizer. The influence of the experimental parameters (reactive gas and solvent nature, stabilizer/metal ratio, reactants concentration, temperature) on the shape of the Pt nanoparticles has been studied. Various shaped platinum nanostructures such as isolated nanoparticles, dendrites or crystalline nanowires were obtained, depending on the reaction conditions. This method takes profit of the mild conditions of chemistry in solution and allows obtaining regular nanostructures, most of them being homogeneous in shape as well as in size (isolated nanoparticles) or diameter/length (nanowires). Transmission electron microscopy and wide-angle X-ray scattering were used as characterization techniques. Beside the Knight-shift effect of platinum, NMR solution investigations clearly evidenced the coordination of the amine at the Pt particles surface and its mobility. This mobility, increased when H2 is used as reactive gas for the precursor decomposition, favors the particles coalescence into nanowires. This phenomenon is also favored by the “soft” template character of the amine in particular in toluene solution.

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