title: Real-Time Imaging of the Formation of Au-Ag Core-Shell Nanoparticles.
abstract: We study the overgrowth process of silver-on-gold nanocubes in dilute, aqueous silver nitrate solution in the presence of a reducing agent, ascorbic acid, using in situ liquid-cell electron microscopy. Au-Ag core-shell nanostructures were formed via two mechanistic pathways: (1) nuclei coalescence, where the Ag nanoparticles absorbed onto the Au nanocubes, and (2) monomer attachment, where the Ag atoms epitaxially deposited onto the Au nanocubes. Both pathways lead to the same Au-Ag core-shell nanostructures. Analysis of the Ag deposition rate reveals the growth modes of this process and shows that this reaction is chemically mediated by the reducing agent.
authors.affiliation: Department of Chemistry, National University of Singapore , 3 Science Drive 3, Singapore 117543.
authors.forename: Shu Fen
authors.initials: SF
authors.lastname: Tan
authors.affiliation: Centre for Bioimaging Sciences and Department of Biological Sciences, National University of Singapore , 14 Science Drive 4, Singapore 117543.|Department of Physics, National University of Singapore , 2 Science Drive 3, Singapore , 117551.|NUSNNI-Nanocore, National University of Singapore , 5A Engineering Drive 1, Singapore , 117411.|Centre for Advanced 2D Materials and Graphene Research Centre, National University of Singapore , 6 Science Drive 2, Singapore 117546.
authors.forename: See Wee
authors.initials: SW
authors.lastname: Chee
authors.affiliation: Centre for Bioimaging Sciences and Department of Biological Sciences, National University of Singapore , 14 Science Drive 4, Singapore 117543.|Department of Physics, National University of Singapore , 2 Science Drive 3, Singapore , 117551.|NUSNNI-Nanocore, National University of Singapore , 5A Engineering Drive 1, Singapore , 117411.|Centre for Advanced 2D Materials and Graphene Research Centre, National University of Singapore , 6 Science Drive 2, Singapore 117546.
authors.forename: Guanhua
authors.initials: G
authors.lastname: Lin
authors.affiliation: Institute of Materials Research and Engineering, A*STAR (Agency for Science, Technology and Research) , 2 Fusionopolis Way, Singapore 138634.|Department of Materials Science and Engineering, National University of Singapore , 9 Engineering Drive 1, Singapore 117575.
authors.forename: Michel
authors.initials: M
authors.lastname: Bosman
authors.affiliation: Institute of Materials Research and Engineering, A*STAR (Agency for Science, Technology and Research) , 2 Fusionopolis Way, Singapore 138634.
authors.forename: Ming
authors.initials: M
authors.lastname: Lin
authors.affiliation: Centre for Bioimaging Sciences and Department of Biological Sciences, National University of Singapore , 14 Science Drive 4, Singapore 117543.|Department of Physics, National University of Singapore , 2 Science Drive 3, Singapore , 117551.|NUSNNI-Nanocore, National University of Singapore , 5A Engineering Drive 1, Singapore , 117411.|Centre for Advanced 2D Materials and Graphene Research Centre, National University of Singapore , 6 Science Drive 2, Singapore 117546.
authors.forename: Utkur
authors.initials: U
authors.lastname: Mirsaidov
authors.affiliation: Department of Chemistry, National University of Singapore , 3 Science Drive 3, Singapore 117543.|Centre for Advanced 2D Materials and Graphene Research Centre, National University of Singapore , 6 Science Drive 2, Singapore 117546.
authors.forename: Christian A
authors.initials: CA
authors.lastname: Nijhuis
mesh_terms: D006046:Gold / Q000737:chemistry*; D053768:Metal Nanoparticles / Q000737:chemistry*; D046529:Microscopy, Electron, Transmission / Q000379:methods*; D036103:Nanotechnology / Q000379:methods; D012834:Silver / Q000737:chemistry*
chemical_list: D012834:Silver; D006046:Gold