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Advances in Physical Chemistry
Volume 2011 (2011), Article ID 249097, 9 pages
http://dx.doi.org/10.1155/2011/249097
Research Article

Gamma Radiolytic Formation of Alloyed Ag-Pt Nanocolloids

1Elkay Chemicals Private Limited, Bhosari, Pune 411061, India
2Department of Chemical Engineering, Indian Institute of Technology Bombay, Mumbai 400076, India
3Department of Chemistry, University of Pune, Pune 411007, India

Received 24 September 2010; Revised 30 January 2011; Accepted 7 February 2011

Academic Editor: Günther Rupprechter

Copyright © 2011 M. K. Temgire et al. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

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.