Growth Kinetic Study of Tannic Acid Mediated Monodispersed Silver Nanoparticles Synthesized by Chemical Reduction Method and Its Characterization

Abstract

The complex process of nanoparticle formation in an aqueous solution is governed by kinetics and thermodynamic factors. This paper describes a room-temperature growth kinetic study and evaluation of thermodynamic activation parameters of monodispersed silver nanoparticles (AgNPs) synthesized in alkaline medium by chemical reduction method using AgNO 3 as a source of Ag + ions and tannic acid (TA) as a reductant (reducing agent) as well as a capping or stabilizing agent in the absence of any other external stabilizer. A simple and conveniently handled reaction process was monitored spectrophotometrically to study the growth kinetics in an aqueous solution as a function of the concentration of silver ion, hydroxide ion, and TA, respectively. The neutral nucleophilic group donates the electron density via a lone pair of electrons to Ag + ions for the reduction process, i.e., for the nucleation of AgNPs colloid. Also, a few silver ions form a silver oxide, which also facilitates the nucleation center to enhance the growth of AgNPs colloid. The decrease and increase in rate constant on varying the TA concentration showed its adsorption onto the surface of metallic AgNPs and stabilized by polygalloyl units of TA and were the main elements to control the growth kinetics. Consequently, stabilized TA-mediated AgNPs are formed using the electron donated by quinone form of TA followed by a pseudo-first-order reaction. Apart from this, nanoparticles formed were characterized using UV–visible spectrophotometry, Fourier transform infrared spectroscopy, field emission scanning electron microscopy, energy-dispersive X-ray spectroscopy, transmission electron microscopy, and powder X-ray diffraction techniques to confirm its formation during the present kinetic study.

Fabrication of α-Fe2O3 Nanostructures: Synthesis, Characterization, and Their Promising Application in the Treatment of Carcinoma A549 Lung Cancer Cells

“…The Williamson-Hall (W-H) plot given in Figure 2 b was also used to calculate the grain size as well as the strain of the α-Fe 2 O 3 NPs. 33 …”

“…The crystal structure of α-Fe 2 O 3 NPs was well matched with JCPDS card numbers 33-0664 and 34-1266. − The average crystallite size ( D ) of synthesized α-Fe 2 O 3 NPs was calculated using Debye–Scherrer’s relation and was found to be 45 nm (mesoporous range). The Williamson-Hall (W-H) plot given in Figure b was also used to calculate the grain size as well as the strain of the α-Fe 2 O 3 NPs …”

“…These have been investigated to produce more stable, soluble, biocompatible, and size-controlled NPs with desired shapes such as spherical, nanoflowers, nanotubes, and nanowires. Several chemical routes such as sol–gel, − co-precipitations, hydrothermal, sonochemical, microwave-assisted, physical routes as spray pyrolysis, chemical reduction, ,− thermal decompositions, and green synthesis as a biological route were used for the synthesis of metal NPs. Many researchers have successfully synthesized iron-based NPs for their application in in vitro and in vivo analysis − and obtained good results, i.e.…”

Kinetic and Mechanistic Studies of the Formation of Silver Nanoparticles by Nicotinamide as a Reducing Agent

“… 44 However, a few of the silver ions under alkaline conditions form silver oxide. 44 , 45 , 49 This silver oxide supports the nucleation process, and when this surface becomes constant, the rate constant again starts falling. The existence of silver as silver oxide was also confirmed by EDS (see section 3.1.2 ) and PXRD studies (see section 3.1.4 ).…”

Novel pathway for the sonochemical synthesis of silver nanoparticles with near-spherical shape and high stability in aqueous media

“…Furthermore, the sonochemical method differs from the NP wet synthesis methods by not requiring relative high temperatures to promote the synthesis reaction 25 , long reaction times 26 , pH control of the NP suspension 27 , use of shape control agents (e.g. tannic acid) 28 , and use of steric capping agents to control shape and stability of NPs 29 . More details on the different conditions necessary to generate monodispersed and quasi-spherical AgNPs using classical methods are summarized in previous studies 1 .…”