水合肼还原氢氧化镍合成镍金属颗粒

Synthesis of Nickel Powders by Hydrazine Hydrate Reduction of Nickel Hydroxide

摘要:

用氢氧化镍在水溶液中被还原制备了窄粒度分布的微细镍粉，分析了镍颗粒的形成和还原途径，讨论了水合肼与氢氧化镍摩尔比、水合肼浓度和表面活性剂PEG6000的添加量对镍颗粒的粒径大小、表面形貌和分散性的影响。结果表明：镍颗粒在氢氧化镍表面完成形核，反应过程中氢氧化镍逐渐溶解。随着水合肼与氢氧化镍反应摩尔比的提高，镍颗粒的粒径先变小后变大；随着水合肼浓度的提高，镍颗粒的粒径变小；少量添加表面活性剂PEG6000使镍颗粒的分散性得到改善，更高的表面活性剂添加量使镍一次颗粒趋于保留氢氧化镍的形貌。通过调节表面活性剂添加量可以使平均粒径控制在1~2 μm。

Abstract:

Fine nickel powders with a narrow particle size distribution were prepared by reducing nickel hydroxide in aqueous solution. The formation and reduction pathways of nickel powder were analyzed, as well as the effects of the molar ratio of hydrazine hydrate to nickel hydroxide, hydrazine concentration, and the dosage of surfactant PEG6000 on particle size, surface morphology, and dispersion. Results reveal that the nickel particle nucleation occurs on the nickel hydroxide surface, and the nickel hydroxide gradually dissolves during the reaction. With the increase in molar ratio of hydrazine hydrate to nickel hydroxide, the nickel particle size is initially decreased and then increased. Higher hydrazine hydrate concentrations result in smaller particle sizes. A small amount of PEG6000 surfactant can improve dispersion of nickel particles, but a higher amount of PEG6000 surfactant results in the maintenance of the morphology of nickel hydroxide. Adjusting the surfactant dosage can control the average particle size between 1–2 μm.