Preparations of Nickel, Cobalt, and Iron Nanoparticles through the Rapid Expansion of Supercritical Fluid Solutions (RESS) and Chemical Reduction

Nanoscale materials have attracted a great deal of attention for their interesting chemical and physical properties and potential technological applications. The preparation of nanoscale materials with desired properties represents a significant challenge. Here we report a facile and flexible method for preparing stable suspensions of polymer-protected nickel, cobalt, and iron nanoparticles. The method is based on the rapid expansion of supercritical fluid solutions (RESS), coupled with chemical reduction. The metal nanoparticles thus prepared were characterized using X-ray powder diffraction and transmission electron microscopy (TEM) methods. The TEM results show that the metal nanoparticles have reasonably narrow size distributions.