Structural aspects of nanoparticles formation in thermal decomposition of aqua solutions of nickel acetate ammines

Ni/NiO nanopowders have been prepared by using thermal decomposition of aqua solutions of nickel acetate ammine complexes in air at the annealing temperature range 300-500 °C and time of decomposition from 30 to 180 min. Particle size of powders has been investigated with transmission electron microscopy (TEM) and scanning electron microscopy (SEM). Powders pore structure has been determinated with low temperature nitrogen adsorption method. Thermal decomposition of nickel acetate ammines resulted in formation of plate-like particles. Formation of plate-like particles were occurred with joining in groups of 3-4 spherical-like nucleuses. Sizes of spherical-like nucleuses were increased from 5 to 20-25 nm with annealing temperature rising from 300 to 500 °C, respectively. Sizes of plate-like particles were height 5 nm and length 20-30 nm at 350 °C. At 400 and 500 °C length of plate-like particles was 80-100 and 100-200 nm, height 20-30 and 50-100 nm and one particle contained 2 or more layers of spherical-like nucleuses. Spherical secondary aggregates of nanoparticles were formed with joining of 3-4 or more plate-like particles. Sizes of secondary aggregates increased from 30 to 400-520 nm for 300 to 500 °C, respectively.