title: Gold Nanoframes by Nonepitaxial Growth of Au on AgI Nanocrystals for Surface-Enhanced Raman Spectroscopy.
abstract: Plasmonic noble metal nanoparticles with defined interior nanogaps are of great significance to surface-enhanced Raman spectroscopy (SERS) applications owing to the presence of intraparticle hotspots. In this contribution, we discovered site-selective nonepitaxial growth of Au on nonmetallic AgI nanocrystals, and on the basis of this observation, we designed an unconventional route to synthesize monometallic Au nanoframes that possess ∼7 nm of interior nanogaps and ∼23 nm of overall size by templating of small AgI nanocrystals. Chemical bonding between Au and the iodide-rich surface of the AgI nanocrystals was proposed to play a critical role in the nonepitaxial growth of the Au nanoframes against the AgI nanocrystals. The Au nanoframes obtained from this synthesis showed superior SERS activity in detecting molecules of interest in low concentrations owing to the presence of intraparticle hotspots in additional to the interparticle ones, benchmarking against Au nanospheres. This intriguing synthesis may open up new opportunities toward a variety of noble metal/semiconductor nanoconjugates for a broad range of applications such as synergistic catalysis.
authors.affiliation: †Center for Materials Chemistry, Frontier Institute of Science and Technology, and MOE Key Laboratory for Nonequilibrium Synthesis and Modulation of Condensed Matter, Xi'an Jiaotong University, Xi'an, Shaanxi 710054, China.
authors.forename: Lei
authors.initials: L
authors.lastname: Zhang
authors.affiliation: †Center for Materials Chemistry, Frontier Institute of Science and Technology, and MOE Key Laboratory for Nonequilibrium Synthesis and Modulation of Condensed Matter, Xi'an Jiaotong University, Xi'an, Shaanxi 710054, China.
authors.forename: Tingzhuo
authors.initials: T
authors.lastname: Liu
authors.affiliation: †Center for Materials Chemistry, Frontier Institute of Science and Technology, and MOE Key Laboratory for Nonequilibrium Synthesis and Modulation of Condensed Matter, Xi'an Jiaotong University, Xi'an, Shaanxi 710054, China.
authors.forename: Kai
authors.initials: K
authors.lastname: Liu
authors.affiliation: §School of Chemistry and Chemical Engineering, Shanghai Jiao Tong University, Shanghai 200240, China.
authors.forename: Lu
authors.initials: L
authors.lastname: Han
authors.affiliation: ‡Department of Chemistry, University of California, Riverside, California 92521, United States.
authors.forename: Yadong
authors.initials: Y
authors.lastname: Yin
authors.affiliation: †Center for Materials Chemistry, Frontier Institute of Science and Technology, and MOE Key Laboratory for Nonequilibrium Synthesis and Modulation of Condensed Matter, Xi'an Jiaotong University, Xi'an, Shaanxi 710054, China.
authors.forename: Chuanbo
authors.initials: C
authors.lastname: Gao
keywords: gold nanoframe; hotspot; nanogap; nonepitaxial growth; surface-enhanced Raman spectroscopy