Advanced bimetallic In–Cu/Ag/Au nanostructures via microemulsion-based reaction

Bimetallic nanomaterials and nanostructures constituted of the coinage metals (Cu, Ag, Au) and indium with elaborate compositions and structures are realized viaa microemulsion-based approach. In detail, this comprises Cu sub(11)In sub(9)uInn corehell-Ahell-B nanoparticles, In-Ag Janushead-like nanoparticles, Ag super(0) hollow spheres, Ag sub(3)Inn corehell nanoparticles, AuuIn sub(2)n corehell-Ahell-B nanoparticles and AuIn sub(2) nanoparticles. To obtain these advanced architectures, two approaches are applied: (1) In super(0) nanoparticles-pre-synthesized in a microemulsion-were reacted in a follow-up reaction with CuCl sub(2).2H sub(2)O, AgNO sub(3) or KAuCl sub(4); (2) simultaneous co-reduction of InCl sub(3).4H sub(2)O together with CuCl sub(2).2H sub(2)O, AgNO sub(3) or KAuCl sub(4) in a microemulsion. Characterization of the resulting advanced structures and compositions requires elaborate electron microscopy techniques, combined with energy dispersive X-ray spectroscopy for chemical analyses of single nanoparticles as well as X-ray powder diffraction and optical spectroscopy. The versatility of the experimental approach toward complex nanoparticle architectures is related to a precise control and fine-tuning of the experimental conditions. The resulting tool kit of In-Cu/In-Ag/In-Au-based bimetallic and intermetallic nanomaterials and, in general, of nanostructured metal architectures with such variability and complexity have not yet been described.