Study On Preparation Of Nanosized Nickel Powder By Reduction Process Of Liquid Phase

Nano-particle is referred to the particle diameter within 1 to 100 nanometers. For its huge effect of bulk and surface, nanosized nickel powder has so much special performance of magnetism, light absorption, chemical activity, and so on. As a new-style material, nanosized nickel powder is becoming more and more important, and it has broad applied-prospect in many industrial fields, such as spaceflight, aviation, energy sources, electron and environment. At present, there are several methods as following in preparation of nanosized nickel powder: ① decomposing hydroxyl nickel by heating, ②electrolyte, ③reduction process of H2, ④reduction process of hydrazine. Owing to the advantages of facile raw and processed materials, convenient operation, higher efficiency and good quality of products, reduction process of hydrazine has been adopted in this study. The experiment is processed in a plastic reactor or a vitreous reactor whose wall is ameliorated with epoxy resins. And the experiment needs to control reactive temperature by means of putting the reactor in the water of constant temperature. By changing the premier concentration of reactants, the system's pH and temperature, the different kinds of dispersants and the concentration of dispersant, the factors which can affect powder's average diameter and surface morphology in preparation of nanosized nickel powder are studied. The results can provide academic and practical foundation for preparation of nanosized nickel powder. The as-prepared nickel powder is detected by the scanning electron microscope(SEM) and X- ray diffraction(XRD). The results are listed below: ① With mixed reducers, the reaction rate is increased.② By analysis, we find that there is a nickel's self- catalyzing process through the reaction which can accelerate the reaction. ③ The optimum reaction conditions for preparation of nanosized nickel powder are: a. the premier concentration of reactants: [Ni2+]=0.25mol·L-1, [Reducer]/[ Ni2+]=2, b. the system's pH: 9～10, c. the system's temperature: 80℃, d. a kind of special dispersant, e. the concentration of dispersant: 1.5mL dispersant per 500mL reactive solution. ④ Under the above mentioned optimum conditions, high-purity and orbicular, evenly distributed nickel powder with 60nm in average diameter is prepared. ⑤ In this paper, the magnetism performance of nanosized nickel powder was studied.