Adding Two Active Silver Atoms on Au₂₅ Nanoparticle

Abstract

Alloy nanoparticles with atomic monodispersity is of importance for some fundamental research (e.g., the investigation of active sites). However, the controlled preparation of alloy nanoparticles with atomic monodispersity has long been a major challenge. Herein, for the first time a unique method, antigalvanic reduction (AGR), is introduced to synthesize atomically monodisperse Au25Ag2(SC2H4Ph)18 in high yield (89%) within 2 min. Interestingly, the two silver atoms in Au25Ag2(SC2H4Ph)18 do not replace the gold atoms in the precursor particle Au25(SC2H4Ph)18 but collocate on Au25, which was supported by experimental and calculated results. Also, the two silver atoms are active to play roles in stabilizing the alloy nanoparticle, triggering the nanoparticle fluorescence and catalyzing the hydrolysis of 1,3-diphenylprop-2-ynyl acetate.

Identification of an Eight-Electron Superatomic Cluster and Its Alloy in One Co-crystal Structure

“…Prominent silver/gold alloy examples being structurally characterized include Au 25-x Ag x [10], Au 38-x Ag x [11], Au 24 Ag 20 [12], Au 24 Ag 46 [13], Au 12 Ag 32 [3b], Au 25 Ag 2 [14], Ag 28 Au [15], Au 12 Ag 13 [16], Au 80 Ag 30 [17], Au 3 Ag 38 [18], Au 7 Ag 8 [19], and Au x Ag y [20] + via a galvanic replacement method [22]. Despite the tremendous progresses in their synthesis and characterization, the mechanistic studies for the formation of Ag alloy NCs are lagged significantly behind.…”

Ion-precursor and ion-dose dependent anti-galvanic reduction

“…One possible reason is that different ion species possess various reduction potentials and coordination natures. One hour later, the four reactions were stopped by the addition of excessive petroleum ether, the as-obtained precipitates were collected and thoroughly washed with methanol, then used for thin-layer chromatography (TLC) analyses 42,43 (CH 2 Cl 2 -petroleum ether as developing solvent). To unravel this question, we tested the reaction between the anion Au 25 (PET) 18 À (N(C 8 H 17 ) 4 + as the counter ion) and four different silver ion precursors.…”

Tuning Properties in Silver Clusters

“…Nevertheless, by tailoring the properties of the solvents and ligands, some remarkable success has been achieved in obtaining a truly single-sized product of Ag clusters in both aqueous and organic phases using one-pot synthesis approaches. 20,[28][29][48][49] This scaling up of cluster synthesis with no known upper limit (irrespective of pure or doped clusters, Figure 2) reminds us of the molecular nature of these clusters and could facilitate the application of clusters in photocatalysis 50 and sensing [24][25] over large areas in addition to improving the fundamental understanding of their properties. …”