Cu nanowire arrays were synthesized via a porous alumina membrane (PAM) template with a high aspect ratio, uniform pore size (120-140 nm), and ordered pore arrangement. The Cu2O nanowire arrays were prepared from the oxidization of Cu metal nanowire arrays. The electrochemical deposition potential of Cu metal nanowires (-180 mV vs. SCE) was determined from X-ray diffraction (XRD) patterns. The microstructure and chemical composition of Cu nanowire arrays were characterized using field emission scanning electron microscopy (FE-SEM), high resolution transmission electron microscopy (HR-TEM), and X-ray diffraction (XRD). Results indicate that the Cu/Cu2O nanowire arrays assembled into the nanochannel of the porous alumina template with diameters of 120-140 nm. The valence of copper was controlled by the porous alumina template during the annealing process. Copper nanowires transformed to the Cu2O phase with the space limitation of the PAM template. Single-crystal Cu2O nanowire arrays were also obtained under the template embedded. (C) 2010 Elsevier B.V. All rights reserved.