Facile Synthesis of Gold Icosahedra in an Aqueous Solution by Reacting HAuCl₄ with N‐Vinyl Pyrrolidone

Abstract

Herein we describe a protocol that generates Au icosahedra in high yields by simply mixing aqueous solutions of HAuCl(4) and N-vinyl pyrrolidone. Our mechanistic study reveals that water plays an important role in this synthesis: as a nucleophile, it attacks the gold-vinyl complex, leading to the production of an alcohol-based Au(I) intermediate. This intermediate then undergoes a redox reaction in which Au(I) is reduced to Au(0), leading to the formation of Au atoms and then Au icosahedra of about 18 nm in size at a yield of 94 %, together with a carboxylic acid in the final product. This new protocol has also been employed to prepare multiply twinned nanoparticles of Ag (15-20 nm in size), spherical aggregates (25-30 nm in size) of Pd nanoparticles, and very small nanoparticles of Pt (2 nm in size). Since no organic solvent, surfactant, or polymer stabilizer is needed for all these syntheses, this protocol may provide a simple, versatile, and environmentally benign route to noble-metal nanoparticles having various compositions and morphologies.

Biogenic Synthesis of Metal Nanoparticles Using a Biosurfactant Extracted from Corn and Their Antimicrobial Properties

“…In fact these components have been previously reported to act as reducing agents of different metal salts. For instance, unsaturated fatty acids have been recently used as the reducing agents to fabricate gold octahedral and triangular NPs [41,42,43]. Moreover, different proteins, such as human serum albumin (HSA), bovine serum albumin (BSA) or subtilisin Carlsberg (SC), have been also employed in the synthesis of gold NPs [44,45].…”

Gold Nanoparticle Synthesis, Morphology Control, and Stabilization Facilitated by Functional Polymers

“…The authors noted that the mild reducing power of PVP, resulting in a slow reduction rate, played an important role in the formation of nanoplates during nucleation and in their growth into highly anisotropic nanostructures [95]. The same group reported a protocol that generates gold icosahedra of about 18 nm in size in high yields by simply mixing aqueous solutions of HAuCl 4 and PVP [96]. This protocol was also used to prepare multiply twinned silver nanoparticles (15-20 nm in size), spherical aggregates (25-30 nm in size) of Pd nanoparticles, and very small (2 nm) Pt nanoparticles [96].…”

Decahedral and icosahedral twin crystals of silver: Formation and morphology evolution

“…In previous reports, such twin particles in small sizes have been produced by vapor phase deposition, which are suitable for the investigation of nucleation and morphology evolution using transmission-and scanning electron microscopes (TEM and SEM) [8][9][10][11][12]. A recent trend is the emphasis on large scale synthesis employing various wet chemistry methods [4,[13][14][15][16][17][18]. For the detailed understanding of the cluster nucleation and the subsequent growth of fcc crystals in various interesting morphologies, also a great mass of simulation and calculation results are available [19][20][21][22][23][24][25], which mostly are waiting for the mutual scrutiny with experimental facts.…”