Template-free Synthesis of One-dimensional Cobalt Nanostructures by Hydrazine Reduction Route

Abstract

One-dimensional cobalt nanostructures with large aspect ratio up to 450 have been prepared via a template-free hydrazine reduction route under external magnetic field assistance. The morphology and properties of cobalt nanostructures were characterized by scanning electron microscopy, X-ray diffractometer, and vibrating sample magnetometer. The roles of the reaction conditions such as temperature, concentration, and pH value on morphology and magnetic properties of fabricated Co nanostructures were investigated. This work presents a simple, low-cost, environment-friendly, and large-scale production approach to fabricate one-dimensional magnetic Co materials. The resulting materials may have potential applications in nanodevice, catalytic agent, and magnetic recording.

Keywords: Cobalt nanowires; Hydration hydrazine reduction; Magnetic field assistance.

Figure 1

SEM images with the same magnification times of Co nanostructures prepared at different reaction temperatures: a 40°C; b 60°C; c 80°C.

Figure 2

SEM images of products prepared in different Co ion concentrations under a 0.40 T magnetic field: a 0.01 mol/l; b 0.1 mol/l; c 0.5 mol/l.

Figure 3

SEM images of samples prepared under different magnetic fields: a 0 T; b 0.15 T; c 0.40 T.

Figure 4

XRD pattern of Co nanowires prepared at 60°C under a 0.40 T magnetic field.

Figure 5

Hysteresis loops of Co nanostructures measured at different intensity of applied field: Zero-field, 0.15 T-field, and 0.40 T-field.