Ahmed, Jahangeer and Ganguly, Aparna and Saha, Soumen and Gupta, Govind and Trinh, Phong and Mugweru, Amos M. and Lofland, Samuel E. and Ramanujachary, Kandalam V. and Ganguli, Ashok K. (2011) Enhanced Electrocatalytic Activity of Copper-Cobalt Nanostructures. JOURNAL OF PHYSICAL CHEMISTRY C, 115 (30). pp. 14526-14533. ISSN 1932-7447

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Abstract

Novel core–shell nanostructures containing Cu and Co have been synthesized using the microemulsion method at 700 °C. The core consists of Cu–Co composite particles, whereas the shell is composed of Cu–Co alloy particles (shell thickness 12 nm). It is to be noted that in bulk Cu–Co binary system there is practically no miscibility. TEM studies show formation of spherical-shaped nanoparticles of core–shell structures. The composition of the core (Cu–Co composite) and shell (Cu–Co alloy) were confirmed by XPS studies. The formation of the Cu–Co alloy as the shell is mainly driven by surface energy considerations. We have also obtained Cu–Co nanocomposites (by controlling the concentration of reducing agent) with particle size in the range of 40–200 nm. These Cu–Co nanostructures show ferromagnetic behavior at 4 K. The saturation magnetization of the core–shell (Cu–Co composite @ Cu–Co alloy) nanostructure (125 emu/g) is found to be higher than that of pure Cu–Co nanocomposite or alloy, which may be useful for applications as a soft magnet. Electrochemical studies of these nanocrystalline Cu–Co particles show higher hydrogen evolution efficiencies (5 times) compared to bulk (micrometer-sized) Cu–Co alloy particles.

Item Type:	Article
Additional Information:	Copyright for this article belongs to M/s American Chemical Society.
Subjects:	Chemistry Chemistry > Physical Chemistry Materials Science Nanoscience/ Nanotechnology
Divisions:	UNSPECIFIED
Depositing User:	Mr. Abhishek Yadav
Date Deposited:	10 Dec 2012 08:04
Last Modified:	10 Dec 2012 08:04
URI:	http://npl.csircentral.net/id/eprint/889

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