Abstract
The kinetics of synthesizing process of nickel oxide nanopowder by the thermal decomposition of nickel hydroxide in various environments (fixed layer, fixed layer with a magnetic field and vortex layer) at temperatures from 220 to 280°C were studied. Ni(OH)2 nanopowder was prepared in advance by chemical deposition from an aqueous solution of nickel nitrate (10 wt. %) and alkali NaOH (10 wt. %) at room temperature, pH=9. The crystal structure and composition of the samples were studied by X-ray phase analysis. The specific surface area S of the powders was measured using BET method by low-temperature nitrogen adsorption. The size and morphology of the particles investigated by scanning electron microscope. It is show that the magnetic field does not actually affect the rate of the thermal decomposition process. It is shown that the thermal decomposition process in the vortex layer proceeds much more intensively than in the stationary layer (5–10 times). NiO nanoparticles obtained by thermal decomposition of nickel hydroxide at 280°C in various environments have different sizes and morphologies. It is show that the thermal decomposition in a magnetic field promotes rounding of the boundaries of nanoparticles and the vortex layer activates their coagulation process.
Keywords
Kinetics, nickel hydroxide, nickel oxide, thermal decomposition, nanoparticle, nanopowder, fixed layer, vortex layer, magnetic field, activation energy.