Monodisperse sub-10nm gold nanoparticles by reversing the order of addition in Turkevich method – The role of chloroauric acid

Sivaraman, Sankar Kalidas; Kumar, Sanjeev; Santhanam, Venugopal

doi:10.1016/j.jcis.2011.06.015

Cited by 143 publications

(115 citation statements)

References 47 publications

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“…They also have observed that the diameter of the obtained GNPs levels off at very high citrate to gold(III) molar ratios (Ct/Au≥14:1) [5]. Puntes group [21] and Sivaraman et al [22] have shown that if the sequence of the addition of citrate and gold chloride is reversed, the GNPs formed are smaller and narrower in size distribution. Moreover, gold salt concentrations much higher than 0.25 mM have been studied by other groups.…”

Section: Introductionmentioning

confidence: 94%

Effect of high gold salt concentrations on the size and polydispersity of gold nanoparticles prepared by an extended Turkevich–Frens method

et al. 2012

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The Turkevich-Frens synthesis starting conditions are expanded, ranging the gold salt concentrations up to 2 mM and citrate/gold(III) molar ratios up to 18:1. For each concentration of the initial gold salt solution, the citrate/gold(III) molar ratios are systematically varied from 2:1 to 18:1 and both the size and size distribution of the resulting gold nanoparticles are compared. This study reveals a different nanoparticle size evolution for gold salt solutions ranging below 0.8 mM compared to the case of gold salt solutions above 0.8 mM. In the case of [Au 3+ ]<0.8 mM, both the size and size distribution vary substantially with the citrate/gold(III) ratio, both displaying plateaux that evolve inversely to [Au 3+ ] at larger ratios. Conversely, for [Au 3+ ]≥0.8 mM, the size and size distribution of the synthesized gold nanoparticles continuously rise as the citrate/gold(III) ratio is increased. A starting gold salt concentration of 0.6 mM leads to the formation of the most monodisperse gold nanoparticles (polydispersity index< 0.1) for a wide range of citrate/gold(III) molar ratios (from 4:1 to 18:1). Via a model for the formation of gold nanoparticles by the citrate method, the experimental trends in size could be qualitatively predicted: the simulations showed that the destabilizing effect of increased electrolyte concentration at high initial [Au 3+ ] is compensated by a slight increase in zeta potential of gold nanoparticles to produce concentrated dispersion of gold nanoparticles of small sizes.

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Section: Introductionmentioning

confidence: 94%

Effect of high gold salt concentrations on the size and polydispersity of gold nanoparticles prepared by an extended Turkevich–Frens method

et al. 2012

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“…[13,14] A increasing temperature) and also by increasing the concentration of DCA. [15][16][17][18][19][20] Once particles are formed, disproportionation can also occurs at particle surface leading to nucleus growth and also to the regeneration of some Au III species.…”

Section: Introductionmentioning

confidence: 99%

“…[Au III ], [27,28] X, [8,[27][28][29][30][31][32][33] [DCA], [15,17,18,20] [electrolyte] [34] , pH, [15,19,24] temperature [35,36] , initiation method [37] ) that enable to obtain, eventually in high quantity, AuNPs with radius ranging between 2 and 75 nm with narrow size and shape polydispersity. Among these parameters the reactant ratio, X, is the oldest and probably the most exploited to modify AuNPs size.…”

Section: Introductionmentioning

confidence: 99%

Shape-Tailored Colloidal Molecules Obtained by Self-Assembly of Model Gold Nanoparticles with Flexible Polyelectrolyte

Shi

Carn

2015

Langmuir

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ABSTRACT.We study the effect of citrate to gold molar ratio (X) on the size of citrated gold nanoparticles (AuNPs). This dependence is still a matter of debate for X  3 where the polydispersity is yet minimized. Indeed, there is no consensus between experiments proposed so far for comparable experimental conditions. Nonetheless, the sole available theoretical prediction has never been validated experimentally in this range of X. We show unambiguously using 3 techniques (UV-Vis spectroscopy, dynamic light scattering and transmission electronic microscopy), 2 different synthetic approaches (Direct, Inverse) and 10 X values for each approach that AuNPs' size decay as a monoexponential with X. This result is, for the first time, in agreement with the sole available theoretical prediction by Kumar et al. on the whole studied range of X.2

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“…At concentrations lower than 1 m m , the suspensions were stable even after a few months, whereas at higher concentrations, precipitation on the walls of the container occurred within days after the preparation of the solutions. More recently, monodispersed sub-10 nm gold (5.7 ± 0.8 nm) [70] and silver (average size of 1.6 nm) [69] nanoparticles could be obtained via modified Turkevich methods.…”

Section: Citrate-mediated Synthesis (Turkevich Method)mentioning

confidence: 99%

Surfactant-free solution-based synthesis of metallic nanoparticles toward efficient use of the nanoparticles’ surfaces and their application in catalysis and chemo-/biosensing

Kawasaki

2013

Nanotechnology Reviews

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Abstract:The choice of stabilizer and the stabilizer-toprecursor ions molar ratio during metal nanoparticle synthesis are important for controlling the shape, size, and dispersion stability of the nanoparticles. However, the active sites on the nanoparticles surfaces may be blocked by the stabilizing agents used, resulting in a less-than-effective utilization of the surfaces. In this review, various surfactant-free solution-based methods of synthesizing metal nanoparticles are described, along with the applications of such nanoparticles in catalysis and sensing. " Surfactant-free " synthesis does not imply truly bare metal nanoparticles synthesis but implies one where the metal nanoparticles are prepared in the absence of additional stabilizing agents such as thiolate and phosphine compounds, surfactants, and polymers. These metal nanoparticles are stabilized by the solvents or the simple ions of the reducing agents or low-molecular-weight salts used. Surfactant-free synthesis of metal nanoparticles via photochemical-, ultrasonochemical-, and laser ablation-mediated synthesis methods is also described. Because of the effective utilization of their surfaces, metal nanoparticles prepared without surfactants, polymers, templates, or seeds are expected to exhibit high performance when used in catalysis (synthetic catalysis and electrocatalysis) and sensing (surface-enhanced Raman scattering (SERS)), surfaceassisted laser desorption/ionization-mass spectrometry (SALDI-MS)).

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Monodisperse sub-10nm gold nanoparticles by reversing the order of addition in Turkevich method – The role of chloroauric acid

Cited by 143 publications

References 47 publications

Effect of high gold salt concentrations on the size and polydispersity of gold nanoparticles prepared by an extended Turkevich–Frens method

Effect of high gold salt concentrations on the size and polydispersity of gold nanoparticles prepared by an extended Turkevich–Frens method

Shape-Tailored Colloidal Molecules Obtained by Self-Assembly of Model Gold Nanoparticles with Flexible Polyelectrolyte

Surfactant-free solution-based synthesis of metallic nanoparticles toward efficient use of the nanoparticles’ surfaces and their application in catalysis and chemo-/biosensing

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