•  
  •  
 
Nano Research

Article Title

Exploring the synthesis conditions to control the morphology of gold-iron oxide heterostructures

Authors

Pablo Tancredi, Laboratory of Amorphous Solids, INTECIN, Faculty of Engineering, University of Buenos Aires – CONICET, Buenos Aires, CP C1063ACV, Argentina
Luelc Souza da Costa, Department of Inorganic Chemistry, Institute of Chemistry, University of Campinas (UNICAMP), CP6154, 13083-970, Campinas, SP, Brazil Brazilian Nanotechnology National Laboratory (LNNano), Rua Giuseppe Máximo Scolfaro 10000, Campinas, SP, Brazil
Sebastian Calderon, International Iberian Nanotechnology Laboratory (INL), Av. Mestre José Veiga s/n, 4715-330 Braga, Portugal
Oscar Moscoso-Londoo, “Gleb Wataghin” Institute of Physics, University of Campinas (UNICAMP), CEP 13083-859, Campinas, SP, Brazil Autonomous University of Manizales, Antigua Estación del Ferrocarril, Manizales, CP 170001, Colombia
Leandro M. Socolovsky, Facultad Regional Santa Cruz, Universidad Tecnológica Nacional - CIT Santa Cruz (CONICET) – Av de los Inmigrantes 555, Río Gallegos, Santa Cruz, Argentina
Paulo J. Ferreira, International Iberian Nanotechnology Laboratory (INL), Av. Mestre José Veiga s/n, 4715-330 Braga, Portugal Materials Science and Engineering Program, The University of Texas at Austin, Austin, Texas 78712, USA
Diego Muraca, “Gleb Wataghin” Institute of Physics, University of Campinas (UNICAMP), CEP 13083-859, Campinas, SP, Brazil
Daniela Zanchet, Department of Inorganic Chemistry, Institute of Chemistry, University of Campinas (UNICAMP), CP6154, 13083-970, Campinas, SP, Brazil
Marcelo Knobel, “Gleb Wataghin” Institute of Physics, University of Campinas (UNICAMP), CEP 13083-859, Campinas, SP, Brazil

Keywords

nanoparticles, gold–iron oxide heterostructures, heterogeneous nucleation, epitaxial growth, HR-microscopy

Abstract

Gold–iron oxide nano-heterostructures with a clear and well-defined morphology were prepared via a seed-assisted method. The synthesis process and the events of heterogeneous nucleation during the decomposition of the iron precursor were carefully studied in order to understand the mechanism of the reaction and to tailor the architecture of the fabricated heterostructures. When employing Au seeds of 3 and 5 nm, nanoparticles with a dimer-like morphology were produced due to the occurrence of a single iron oxide nucleation event. Otherwise, multi-nucleation events could be favored by two mechanisms: (i) by the incorporation of a reducing agent and the slowing down of the heating protocol, leading to a core–shell system; (ii) by the increase of the Au seed size to 8 nm, leading to a flower-like system. Further increase of the Au seed size to 12 nm using similar synthesis conditions promotes the homogeneous nucleation and growth of the iron oxide phase, without formation of heterostructures. An in-depth study was performed on the gold–iron oxide heterostructures to confirm the epitaxial growth of the oxide domain over the Au seed and to analyze the elemental distribution of the components within the heterostructures. Finally, it was found that the modification of the plasmonic properties of the Au nanoparticles are strongly influenced by the architecture of the heterostructure, with a more pronounced damping effect for the systems produced after multi-nucleation events.

Graphical Abstract

Publisher

Tsinghua University Press

Share

COinS