Preparation of nanometer-sized nickel powders by hydrothermal hydrogen reduction of Ni(OH)2 slurry

The nickel powder samples obtained at different reaction steps of the hydrogen reduction of Ni(OH)2 slurries were examined by XRD, TEM, SEM and other methods. The obvious differences between samplings from acidic medium with pH12 were observed. The mechanism of hydrogen reduction of Ni(OH)2 slurry with pH2+ ions dissociated from basic nickel sulfates like Ni(SO4)0.3(OH)1.4 but for Ni(OH)2 slurry with pH>12 the mechanism was confirmed to be a heterogenous reaction of Ni(OH)2 solid particles and activated hydrogen occurred at the surface of Ni(OH)2.