Syntheses and Characterization of Nearly Monodispersed, Size-Tunable Silver Nanoparticles over a Wide Size Range of 7–200 nm by Tannic Acid Reduction

Abstract

Nearly monodispersed spherical silver nanoparticles (Ag NPs) were synthesized by using tannic acid (TA) as both reductant and stabilizer in a 30 °C water bath. The size of the as-prepared Ag NPs could be tuned in a range of 7-66 nm by changing the molar ratio of TA to silver nitrate and pH of the reaction solutions. UV-vis spectra, TEM observations, and temporal evolution of the monomer concentrations for the reactions carried out at different experimental conditions showed that the improved size distribution and size tunability of the Ag NPs were mainly attributed to the use of TA, which could promote the balance of nucleation and growth processes of the NPs effectively. The size of the Ag NPs was extendable up to 200 nm in one-pot fashion by the multi-injection approach. The size-dependent surface-enhanced Raman scattering (SERS) activity of the as-prepared Ag NPs was evaluated, and the NPs with size around 100 nm were identified to show a maximum enhanced factor of 3.6 × 10(5). Moreover, the as-prepared TA-coated Ag NPs presented excellent colloidal stability compared to the conventional citrate-coated ones.

Morphology Control of Ag Polyhedron Nanoparticles for Cost‐Effective and Fast Solar Steam Generation

“…As can be seen from Figure a–c, only one peak shows strong absorption but with a broad FHWM and tailing effect and this phenomenon is agreed with previous reports . Taking the narrow size distribution of each of the cases in Figure into consideration, the tailing effect does not result from the mixed structures and nonuniformity.…”

Direct-written polymer field-effect transistors operating at 20 MHz

“…Other synthesis protocols have been recently proposed using tannic acid for controlling nanoparticle size either in combination with sodium citrate43 or by careful control of the reaction mixture pH44. However, the reported conditions appear to be unsuitable for the preparation of AgNPs in such large amounts as required for conductive ink applications.…”

“…We have, therefore, conducted an optimization of the reaction conditions and in particular temperature, reagents ratio and order of addition of the reagents, to allow the preparation of 23.8 ± 4.0 nm AgNPs (Fig. 1a and b) with a production scale-up factor between 150 and 300 times and yet of comparably narrow size distribution as those previously reported in the literature424344. In a typical synthesis, our method yields 20 times more AgNPs also with respect to the approach recently reported by Zhang and coworkers45.…”

Empirical structural design of core@shell Au@Ag nanoparticles for SERS applications

“…11,12 Up to date, there are a limited number of protocols available to produce uniform, spherical Ag NPs with controlled sizes. [13][14][15][16][17] Distinct to Ag NPs, uniform Au NPs with different shapes can be easily produced. [18][19][20] This has strongly ecouraged the growth of core@shell (CS) Au@Ag NPs by using pre-formed Au NPs as seeds and the utilization of the Ag shells instead of Ag NPs for SERS studies.…”