Synthesis and characterization of nickel nanoparticles prepared using the aquolif approach

We report on the synthesis of nickel nanoparticles using a combination of chemical reduction and freezing-drying processes that we named the aquolif approach. The X-ray diffraction (XRD) patterns reveal that the synthesized nanoparticles were composed of a single metallic nickel phase. The average crystallite sizes of the nickel nanoparticles were determined using the Scherrer method. The average crystallite sizes increased from 8±3 to 16±3 nm as the annealing temperature increased, which is consistent with the XRD and transmission electron microscopy results. The zero-field-cooling and field-cooling (ZFC-FC) magnetization curves reveal that the nickel nanoparticles exhibited superparamagnetic behavior with a high blocking temperature and a surface effect at lower temperatures. Our experimental results demonstrate that the aquolif approach can be successfully scaled up to industrially prepare other types of metallic nanoparticles.