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

Autor(es)

Tancredi, Pablo ^[1] ; da Costa, Luelc Souza ^{[2, 3]} ; Calderon, Sebastian ^[4] ; Moscoso-Londono, Oscar ^{[5, 6]} ; Socolovsky, Leandro M. ^[7] ; Ferreira, Paulo J. ^{[4, 8]} ; Muraca, Diego ^[5] ; Zanchet, Daniela ^[2] ; Knobel, Marcelo ^[5]

Afiliação do(s) autor(es)

^[1] Univ Buenos Aires, CONICET, Fac Engn, Lab Amorphous Solids, INTECIN, CP C1063ACV, Buenos Aires, DF - Argentina

^[2] Univ Campinas UNICAMP, Inst Chem, Dept Inorgan Chem, CP6154, BR-13083970 Campinas, SP - Brazil

^[3] Brazilian Nanotechnol Natl Lab LNNano, Rua Giuseppe Maximo Scolfaro 10000, Campinas, SP - Brazil

^[4] Int Iberian Nanotechnol Lab INL, Av Mestre Jose Veiga S-N, P-4715330 Braga - Portugal

^[5] Univ Campinas UNICAMP, Gleb Wataghin Inst Phys, BR-13083859 Campinas, SP - Brazil

^[6] Autonomous Univ Manizales, Antigua Estn Ferrocarril, Manizales 170001 - Colombia

^[7] Univ Tecnol Nacl, CIT Santa Cruz CONICET, Fac Reg Santa Cruz, Av Inmigrantes 555, Rio Gallegos, Santa Cruz - Argentina

^[8] Univ Texas Austin, Mat Sci & Engn Program, Austin, TX 78712 - USA

• Tipo de documento: Artigo Científico
• Fonte: NANO RESEARCH; v. 12, n. 8, p. 1781-1788, AUG 2019.
• Citações Web of Science: 1

Resumo

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. (AU)

• Processo FAPESP: 14/26672-8 - Efeitos de interface e superfície em nanoheteroestruturas magnético-metálicas
• Beneficiário: Oscar Moscoso Londono
• Modalidade de apoio: Bolsas no Brasil - Pós-Doutorado
• Processo FAPESP: 11/50727-9 - Desenvolvimento de sistemas para produção de hidrogênio e para geração e utilização de energia eletro-química
• Beneficiário: Ernesto Rafael Gonzalez
• Modalidade de apoio: Auxílio à Pesquisa - Temático