Preparation of nanosized NiO powders by mixing acid and base nickel salts and their reduction behavior

Nanosized NiO powder was prepared by mixing an acid nickel salt and a base nickel salt and their reduction behavior was studied. Ni formate was employed as an acid salt and nickel hydroxide and basic nickel carbonate as base salts. One equivalent acid salt was mixed with 9 equivalent base salt. The mixture of the formate and the carbonate produced similar to 100 nm spherical NiO powder by heat treatment at 750 degrees C/2 h, but the mixture of the formate and the hydroxide gave rise to similar to 100 nm pseudo spherical NiO powder by heat treatment at 600 degrees C/2 h and grew fast to give pseudo cubic crystals of 100 similar to 600 nm by heat treatment at 750 degrees C/2 h. Reduction by hydrogen gas proceeded much faster for the one with the hydroxide than that with the carbonate to give porous body with well grown necks. Their behavior was studied by analysis of TG/DSC, XRD, and SEM.