Synthesis and characterization of Pt-Cu bimetallic alloy nanoparticles by reverse micelles method

Platinum-copper bimetallic alloy nanoparticles were synthesized in water-in-oil (w/o) microemulsions of water/cetyltrimethyammonium bromide (CTAB)/isooctane/n-butanol by the co-reduction of H2PtCl6 and CuCl2 with hydrazine at room temperature. The samples were characterized by high-resolution transmission electron microscopy (HRTEM), X-ray diffraction (XRD) and X-ray photoelectron spectrum (XPS). XRD results show that there is only one peak in the pattern of bimetallic nanoparticles, corresponding to the (1 1 1) plane of the PtCu3 bulk alloy. XPS illustrates that both elements in the nanoparticles are in zero-valence and possess the characteristic metallic binding energy. HRTEM analyses confirm the formation of the PtCu3 alloy nanoparticles with a mean diameter of about 1.6 nm, where the corresponding lattice spacing of 1.87 angstrom is consistent with that of the (200) plane Of PtCu3 bulk alloy. Moreover, the factors influencing the size of PtCu3 nanoparticles had also been investigated and discussed. (c) 2005 Elsevier B.V. All rights reserved.