Electrochemical Preparation of Nickel and Iron Nanoparticles in a Hydrophobic Ionic Liquid

Preparation of nickel and iron nanoparticles was achieved in a room-temperature ionic liquid, 1-butyl-1-methylpyrrolidinium bis(trifloromethylsulfonyl)amide (BMPTFSA) containing Ni(TFSA)(2) or Fe(TFSA)(2). Potentiostatic cathodic reduction of [Ni(TFSA)(3)](-) in Ni(TFSA)(2)/BMPTFSA at -2.2 V vs. ferrocene/ferrocenium (Fc/Fc(+)) changed the color of electrolyte to black, resulted in formation of Ni nanoparticles, which were verified by transmission electron microscopy and energy-dispersive X-ray analysis. Addition of acetonitrile into Ni(TFSA)(2)/BMPTFSA resulted in reduction of the mean diameter of Ni nanoparticles from 3.2 to 1.9 nm. Fe nanoparticles with a mean diameter of 4.6 nm were also obtained from Fe(TFSA)(2)/BMPTFSA at -2.2 V vs. Fc/Fc(+). (C) 2011 The Electrochemical Society. [DOI: 10.1149/2.010112esl] All rights reserved.