Ansari, Jamilur R. and Singh, Neelam and Mohapatra, Satyabrata and Ahmad, Razi and Saha, Nayan Ranjan and Chattopadhyay, Dipankar and Mukherjee, Manabendra and Datta, Anindya (2019) Enhanced near infrared luminescence in Ag@Ag2S core-shell nanoparticles. Applied Surface Science, 463. pp. 573-580. ISSN 0169-4332

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Abstract

Ag-Ag2S core-shell nano-structured particles, prepared by soft chemical route, were found to be luminescent in the near-infrared (NIR) range. The silver nanoparticles were pre-synthesized with size control by poly-vinylpyrrolidone (PVP) polymer capping from silver nitrate solution, by reduction using sodium borohydride in solution, which were further subjected to reaction with sulfur ions in the later stage by mixing controlled amount of Na2S in the solution. With increasing concentration of sulfur ions, the plasmonic peak of Ag showed progressive blue shift and damping, leading to final diminishment. Enhanced NIR luminescence obtained from Ag@Ag2S core-shell nanoparticles were found to be asymmetric and blue shifting with reduced intensity and increasing sulfur ion concentration. The mechanism behind such a beha vior is predicted due to formation of composite layer of Ag2S-Ag both at the surface and the volume, with Ag core at the center, diminishing in size with increasing sulfur concentration. The structure, chemical composition, morphology and final core-shell structure formation were further established by combination of X-ray diffractometry (XRD), X-ray Photoelectron Spectroscopy (XPS) and Transmission Electron Microscopy (TEM) analysis.

Item Type:	Article
Additional Information:	Copyright for this article belongs to M/s Elsevier.
Subjects:	Chemistry > Physical Chemistry Materials Science Applied Physics/Condensed Matter
Divisions:	UNSPECIFIED
Depositing User:	Mr. Yogesh Joshi
Date Deposited:	04 Mar 2020 11:13
Last Modified:	04 Mar 2020 11:13
URI:	http://npl.csircentral.net/id/eprint/4181

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