Effective Synthesis of Magnetic Metal Nickel Nanotubes

Abstract

Using porous anodic alumina (PAA) as the template, we fabricated a highly ordered array of magnetic metal nickel nanotubes by adding the tri-block copolymer F127 (EO108PO69EO108, EO: ethylene oxide, PO: propylene oxide) in a common electrolyte solution and by using electrodeposition technique. This synthetic method is very easy, effective and facile. Especially, the pore wall of the template does not need to be modified. The morphology, structure and magnetic property of the product were characterized by transmission electron microscopy (TEM), scanning electron microscopy (SEM), X-ray diffraction (XRD) and vibrating sample magnetometry (VSM). The face-centered cubic (fcc) structure of nickel was confirmed by X-ray diffraction (XRD). We investigated the effects of experimental parameters such as the electric current density, the concentration of copolymer and electrodeposition time on product morphology by transmission electron microscopy (TEM). Experimental results showed that the wall of nickel nanotubes thickened as current densities and deposition time increased, but the wall thickness was hardly influenced by a change in the concentration of F127. Based on these experimental results, we could control the wall thickness of the nanotubes by adjusting experimental parameters. Magnetic measurements on the array of Ni nanotubes indicated an enhanced coercivity compared to bulk nickel.