Investigation of the Process of Synthesizing Nanosized Nickel Powders by Hydrogen Reduction Under Nonisothermal Conditions

摘要

We study the kinetic characteristics and properties of the product of the process of synthesizing nickel nanopowders by the hydrogen reduction of Ni(OH)(2) hydroxide compound under nonisothermal conditions. It is shown that the process of hydrogen reduction of the nanopowder of Ni(OH)(2) hydroxide takes place within the temperature range 210-300 degrees C with the maximal specific rate equal to 9.44 center dot 10(-8) kg/sec recorded at a temperature of 285 degrees C. The activation energy of the process of reduction of Ni(OH)(2) nanopowder under nonisothermal conditions was estimated as approximate to 54 kJ/mole, which confirms the kinetic conditions of limiting of the process. It is shown that the elevation of temperature up to 285 degrees C enables us to efficiently increase the rate of the total process of hydrogen reduction of Ni(OH)(2) nanopowder (with guaranteeing high quality of the products of reduction). The obtained Ni nanoparticles mainly have round shapes and the sizes from ten to several tens of nanometers with a mean value of 50 nm.