Abstract: Self-sacrificial template, which is freshly precipitated Ni(OH)₂ colloid, is used to fabricate ultrafine core-shell nickel spheres. The size distribution, morphology, chemical and catalyzed properties of the synthesized spheres can be controlled by regulating the preparation conditions. The varying conditions are: initial nickel ion concentration, the pH value of the solution, the scouring agent and the anion in saline solution. With very little Ni²⁺ concentration in the solution, the hollow spheres are formed. The higher the alkali content, the more the ultrafine colloidal cores.

Key words: ultrafine particles; core-shell; self-sacrifice; morphology