Electro-reduction of cuprous chloride powder to copper nanoparticles in an ionic liquid

Cyclic voltammetry of the CuCl powder in a cavity microelectrode revealed direct electro-reduction in solid state in 1-butyl-3-methylimidazolium hexafluorophosphate. Potentiostatic electrolysis of the salt powder (attached to a current collector) in the ionic liquid produced Cu nanoparticles as confirmed by X-ray diffraction, energy dispersive X-ray analysis, scanning and transmission electron microscopy. The particle size decreased down to 10 nin when the electrode potential was shifted from -0.9 V to -1.8 V (versus Ag/Ag+). The electro-reduction and the nanoparticle formation mechanisms were investigated in the ionic liquid and also in aqueous 0.1 mol L-1 KCKlO(4) in which larger Cu particles were obtained. (c) 2007 Elsevier B.V. All rights reserved.