Single Au Atom Doping of Silver Nanoclusters

Abstract

Ag29 nanoclusters capped with lipoic acid (LA) can be doped with Au. The doped clusters show enhanced stability and increased luminescence efficiency. We attribute the higher quantum yield to an increase in the rate of radiative decay. With mass spectrometry, the Au-doped clusters were found to consist predominantly of Au1Ag28(LA)123–. The clusters were characterized using X-ray absorption spectroscopy at the Au L3-edge. Both the extended absorption fine structure (EXAFS) and the near edge structure (XANES) in combination with electronic structure calculations confirm that the Au dopant is preferentially located in the center of the cluster. A useful XANES spectrum can be recorded for lower concentrations, or in shorter time, than the more commonly used EXAFS. This makes XANES a valuable tool for structural characterization.

Rendering hydrophobic nanoclusters water-soluble and biocompatible

“…For the counterions of these [Ag 29 (SSR) 12 (PPh 3 ) 4 ] 3À nanoclusters, the Ag 29 -Na 1 nanocluster comprised three NMPconjoined [Na 1 (NMP) 5 ] + cations per Ag 29 compound ( Fig. 1A and B), whereas each Ag 29 compound matched only one DMFconjoined [Na 3 (DMF) 12 ] 3+ cation in the structure of Ag 29 -Na 3 (Fig.…”

“…The crystal lattice of Ag 29 -Na 1 contained six [Ag 29 (SSR) 12 (-PPh 3 ) 4 ] 3À anions and 18 [Na 1 (NMP) 5 ] + cations (Fig. 1E); by comparison, two [Ag 29 (SSR) 12 (PPh 3 ) 4 ] 3À anions and two [Na 3 (DMF) 12 ] 3+ cations were observed in the unit cell of Ag 29 -Na 3 (Fig.…”

“…Herein, we report a versatile strategy to render hydrophobic nanoclusters water-soluble-the micellization of these nanoclusters in the presence of solvent-conjoined Na + cations. Specically, the [Ag 29 (SSR) 12 (PPh 3 ) 4 ] 3À (SSR ¼ 1,3-benzene dithiol) nanocluster is absolutely hydrophobic; however, in the presence of solventconjoined cations (Na 1 (NMP) 5 or Na 3 (DMF) 12 ) as counterions, Ag 29 @Na compounds ([Ag 29 (SSR) 12 12 ] 3+ , Ag 29 -Na 1 or Ag 29 -Na 3 hereaer because they contain three Na + monomers or one [Na 3 ] 3+ trimer, respectively) show good dissolvability in aqueous solution. A combination of DLS (dynamic light scattering) and aberration-corrected HAADF-STEM (high angle annular dark eld detector scanning transmission electron microscopy) measurements unambiguously shows that the phase-transfer of hydrophobic Ag 29 into water is triggered by the micellization of nanoclusters.…”

Single Atoms on Graphene for Energy Storage and Conversion

“…In addition, X‐ray absorption fine structure (XANFS) is known for accurately reflecting the oscillatory structure of the samples according to the X‐ray absorption coefficient . It generally includes X‐ray absorption near edge structure (XANES) and extended X‐ray absorption fine structure (EXAFS).…”

Molecular reactivity of thiolate-protected noble metal nanoclusters: synthesis, self-assembly, and applications

“…It has been demonstrated that alloying can effectively enhance the stability and materials performance (e.g., luminescence 154 and catalytic activity 99,105,155 ) of metal NCs. In addition to the well-known co-reduction method, the alloying can be achieved at atomic precision through reactions of the preformed metal NCs with various heteroatom sources, including metal cations, 53 M(I)-SR/M(II)-SR complexes, metal NCs, and metal surfaces.…”