title: Formation of one-dimensional Ag-Au solid solution colloids with Au nanorods as seeds, their alloying mechanisms, and surface plasmon resonances.
abstract: In this work, one dimensional (1D) Ag-Au solid solution nanoalloys were synthesized by rapidly diffusing Ag into the preformed Au nanorod (AuNR) seeds at ambient temperature in aqueous solution. By varying the molar ratio of AgCl/AuNR (in gold atoms), two kinds of 1D Ag-Au alloy nanostructures with a narrow size distribution--AgAu nanowires and Ag(33)Au(67) nanorods--could be obtained in high yields when NaCl and polyvinylpyrrolidone (PVP) were used as an additive and capping reagent, respectively. Based on HRTEM imaging combined with a series of control experiments, it is conceivable that vacancy/defect-motivated interdiffusion of Ag and Au atoms coupled with oxidative etching is a crucial stage in the mechanism responsible for this room-temperature alloying process, and the subsequent conjugation of the fused Ag-Au alloyed nanostructures is associated with the formation of the AgAu nanowires. The resulting 1D Ag-Au nanoalloys form stable colloidal dispersions and show unique localized surface plasmon resonance (LSPR) peaks in the ensemble extinction spectra.
authors.affiliation: State Key Laboratory of Materials-Oriented Chemical Engineering, School of Chemistry and Chemical Engineering, Nanjing University of Technology, Nanjing 210009, China.
authors.forename: Tao
authors.initials: T
authors.lastname: Guo
authors.forename: Yiwei
authors.initials: Y
authors.lastname: Tan
mesh_terms: D000497:Alloys / Q000737:chemistry*; D003102:Colloids / Q000737:chemistry*; D006046:Gold / Q000737:chemistry*; D053768:Metal Nanoparticles / Q000737:chemistry; D008855:Microscopy, Electron, Scanning / Q000379:methods; D046529:Microscopy, Electron, Transmission / Q000379:methods; D043942:Nanotubes / Q000737:chemistry*; D053770:Nanowires / Q000737:chemistry; D055095:Optics and Photonics / Q000379:methods; D056951:Photoelectron Spectroscopy / Q000379:methods; D012834:Silver / Q000737:chemistry*; D013056:Spectrophotometry, Ultraviolet / Q000379:methods; D013059:Spectrum Analysis, Raman / Q000379:methods; D020349:Surface Plasmon Resonance / Q000379:methods*; D013696:Temperature; D013816:Thermodynamics
chemical_list: D000497:Alloys; D003102:Colloids; D012834:Silver; D006046:Gold