Gamma Radiolytic Formation of Alloyed Ag‐Pt Nanocolloids

Abstract

Colloidal dispersions of Ag-Pt composite nanoparticles were prepared by gamma radiolysis technique in the presence of nonionic surfactant Brij'97. Simultaneous as well as sequential reduction methods were employed in order to study the structural formation of Ag-Pt bimetallic clusters. Similar shape and trend was observed in optical spectra for both methods. Radiolysis yielded nearly spherical Ag-Pt bimetallic clusters by use of AgNO3 instead of AgClO4. The disappearance of the silver resonance and the simultaneous growth of the 260 nm resonance are independent of cluster structure and degree of alloying. To understand formation of Ag-Pt aggregate, the optical studies were also done as a function of amount of dose absorbed, concentration of surfactant, that is, Brij'97. The shape of the absorption spectrum did not change with increase in gamma radiation dose. TEM analysis exhibited fine dispersions of Ag-Pt clusters surrounded by a mantle when capped with Brij'97. The particle size obtained was in the range of 5–9 nm. On the basis of optical, XRD, and TEM analysis, alloy formation is discussed.

Synthesis of silver–platinum nanoferns substrates used in surface-enhanced Raman spectroscopy sensors to detect creatinine

“…The presence of Pt particles in the AgPt nanoferns thin films lowered the absorbance of Ag particles as they replaced and covered the Ag particles [13]. The reduction of Ag caused the Pt to receive electrons from Ag which lowered the absorbance spectra of Ag [14].…”

Preparation of Nanoparticles

“…Takalani Cele University of South Africa, Pretoria, South Africa *Address all correspondence to: tmadima@yahoo.com specific hydroxyl scavengers are used. Among them, isopropanol is frequently used [60].…”

Nanofl uids for Heat Transfer

“…Gamma radiolysis: the principle of radiolytic synthesis of nanoparticles consists in reducing the metal ions contained in a solution through intermediate species (usually electrons) produced by radiolysis. The synthesis can be described in three parts (i) radiolysis of the solvent, (ii) reduction reaction of metal ions by species produced by radiolysis followed by (iii) coalescence of the produced atoms (Benoit et al, 2009;Ramnani et al, 2007;Temgire et al, 2011).…”