Morphology-Controllable Synthesis of Nickel Nanostructures through Solution Route using Hydrazine Hydrate as a Precipitating Agent

Abstract

Ferromagnetic nickel (Ni) metal nanostructures with controllable morphology and dimensions are of great importance because of both their functionalized properties and potential applications including catalysis, magnetic sensors, magnetic recording media and addressing some basic issues about magnetic phenomena in low-dimensional systems. There are several possible methods of preparing Ni nanostructures. But, according to the massive production needs and the economical aspects, the desired route is the chemical reduction of metal cations from their salt solutions in the presence of a reducing agent. In this present work, morphology controllable synthesis of Ni nanostructures was carried out using hydrazine hydrate (N2H5OH) and Ni-salt (NiCl2·H2O) in the absence of NaOH and pH buffer, which were mostly used in the reported synthesis procedures. It was observed that the Ni nanostructures with spike, grass and fiber-like morphologies are strongly dependent on the way of synthesis, time of reaction and presence of surfactant. X-ray diffractometer (XRD), scanning electron microscopy (SEM) and vibrating sample magnetometer (VSM) were employed to characterize Ni nanostructures with different morphologies. The saturation magnetization (Ms) and coercivity (Hc) value of the Ni nanostructures were very close to the saturation Ms and Hc value of bulk Ni. The structural and microstructural results together with magnetic properties of the nanostructured system clearly show the potential of this technique to obtain morphology controlled property tuning.