Abstract: Nano-sized NiO was prepared by coordination homogeneous precipitation method using ammonia water and Ni（NO3）2·6H2O as raw materials.Influences of various processing parameters in preparation process on the yield of precursor and on mean particle diameter of nano-sized NiO were investigated.Optimum conditions for preparing nano-sized NiO were as follows：nickel ion concentration was 0.8 mol/L，amount-of-substance ratio of ammonia water to nickel nitrate hexahydrate was 3∶1，temperature of precipitation reaction was 80 ℃，reaction time was 90 min，calcination temperature was 400 ℃，and calcination time was 1 h.XRD and TEM etc.were used to characterize crystalline structure and morphology of the product.Results indicated that nano-sized NiO prepared under the optimum conditions had a fine crystal phase of standard face-centered cubic lattice structure with a mean particle diameter of about 12 nm.Shape of nano-sized NiO was spherical. 

Key words: nickel oxide；nanoparticles；coordination homogeneous precipitation method；characterization