Large-Scale Synthesis of Metal Nanocrystals in Aqueous Suspensions

Abstract

Fundamental studies and practical use of metal nanoparticles (NPs) frequently depend on the ability to reproducibly synthesize large quantities of shape-specific NPs. For this reason, facile synthetic procedures are desired that will lead to large quantities of uniformly sized metal NPs exhibiting specific shapes. Here, we report a general approach to the large-scale synthesis of noble metal nanocrystals having well-defined shapes and a narrow size distribution. This method utilizes seed-mediated NP growth in aqueous suspensions of cationic surfactants and metal salts. It leads to a ∼60-fold increase in NP volumetric production capacity, compared to the most widely used solution-based synthetic methods. In addition, it uses up to 100 times less cationic surfactant than conventional solution-based methods. The applicability of the method is demonstrated in the synthesis of Pd nanocubes, rhombic dodecahedra, and polyhedrons with low index facets; branched Pd nanocrystals; alloy Pt/Pd nanocubes; Ag nanocubes. The advantages and limitations of the approach are discussed, including accessible shapes, growth kinetics, and the capability to scale up the synthetic procedure.

Pd Nanoparticle Assemblies as Efficient Catalysts for the Hydrogen Evolution and Oxygen Reduction Reactions

“…Note that, when the concentration of CPC was increased to 42 m m , polyhedral Pd nanostructures with smaller diameters (10 nm) were obtained (Figure D). From these experimental results, we can conclude that the optimal concentration range of CPC for synthesizing porous Pd NPAs is from 0.8 m m to about 21 m m , which is consistent with previous reports …”

Wässrige Goldüberwachsung von Silbernanopartikeln: Vereinigung der plasmonischen Eigenschaften von Silber mit der Funktionalität von Gold

“…Im Vergleich mit anderen AgNC-Synthesemethoden entspricht die Formpräzision dem Stand der Wissenschaft, [11,23] und es ist mçglich, hohe Ausbeuten (> 90 %) unter milden Reaktionsbedingungen und bei quantitativer Silberumwandlung zu erreichen. Ausgehend von den eng verteilten, einkristallinen AuNPs nimmt die Grçße bei der Silberüberwachsung von 41.3 AE 2.6 nm (Durchmesser) auf 69.7 AE 2.9 nm (Kantenlänge) zu.…”

“…In diesem Fall entstehen AgNCs mit scharfen Kanten (siehe die Hintergrundinformationen,S 1u nd S2). Im Vergleich mit anderen AgNC-Synthesemethoden entspricht die Formpräzision dem Stand der Wissenschaft, [11,23] und es ist mçglich, hohe Ausbeuten (> 90 %) unter milden Reaktionsbedingungen und bei quantitativer Silberumwandlung zu erreichen.…”

Controllable Synthesis of Upconversion Nanophosphors toward Scale‐Up Productions

“…This characteristic represents an essential challenge in managing thermodynamic equilibrium for a smooth and uniform synthesis in lab, [ 27,28 ] and the scale‐up process where the breaking of local thermodynamic equilibrium is likely to occur to yield the uncontrollable changes on the phases and other features for the particle, especially the luminescent performance. [ 29,30 ] Despite the understanding on the nucleation mechanism of UCNPs obtained through complicated synthesis, there is little focused discussion on the large‐scale industrial production of UCNPs.…”