Moderating effect of ammonia on particle growth and stability of quasi-monodisperse silver nanoparticles synthesized by the Turkevich method

Abstract

A new method to stabilize silver nanoparticles by the addition of ammonia is proposed. Colloidal dispersions of silver nanoparticles were synthesized by the Turkevich method using sodium citrate to reduce silver nitrate at high pH and at 90 °C. After approximately 12 min, a diluted ammonia solution was added to the reaction flask to form soluble diamine silver (I) complexes that played an important growth moderating role, making it possible to stabilize metallic silver nanoparticles with sizes as small as 1.6 nm after 17 min of reaction. Colloidal dispersions were characterized by UV-visible absorption spectroscopy, X-ray diffraction, and transmission electronic microscopy.

Preparation of antibacterial cotton fabric using chitosan-silver nanoparticles

“…AgNPs were prepared by the reduction of silver nitrate solution with sodium citrate using the standard method described by Turkevich [23]. Aqueous solution of silver nitrate (1.0 mmol l -1 , 500 ml) was heated and stirred gently with a magnetic stirrer up to 90 o C. Then preheated sodium citrate solution (5.0 ml of 0.3 mol l -1 ) at 90 o C was added to the above solution.…”

Nanostructured Assemblies of Gold and Silver Nanoparticles for Plasmon Enhanced Spectroscopy Using Living Biotemplates

“…The plasmonic origin of the phenomenon is fully understood [19,37], and nowadays the major effort focuses on the fabrication of new substrates for SERS [38]. As discussed previously (Figures 2 and 3), the FG and FGS surfaces clearly offer the necessary morphological characteristics of a typical SERS substrate.…”

“…Over the years, a wide variety of molecular targets have been investigated by SERS using active nanoparticles, mainly gold and silver [2,3,11,12,[26][27][28][29][30][31][32][33][34]. The plasmonic origin of the phenomenon is fully understood [19,37], and nowadays the major effort focuses on the fabrication of new substrates for SERS [38]. As discussed previously (Figures 2 and 3), the FG and FGS surfaces clearly offer the necessary morphological characteristics of a typical SERS substrate.…”

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

“…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.…”