中文摘要：

以甲酸钠为还原剂、乙二醇为溶剂、柠檬酸钠为络合剂，采用有机溶胶法制得了粒径为2nm的单分散钴纳米粒子．考查了柠檬酸钠的添加对钴纳米粒子的收率、晶型、粒径及其分布的影响．结果表明：当柠檬酸钠／氯化钴摩尔比从0增至6时，钴纳米粒子的平均粒径从200nm降至2nm；同时，柠檬酸钠对钴纳米粒子的粒径分布也有很好的控制作用，不加柠檬酸钠时所得钴纳米粒子粒径分布很广，从几十纳米到三四百纳米，而添加一定量柠檬酸钠后，所得钴纳米粒子粒径在（2±0．25）nm范围内．实验还发现使用柠檬酸钠作为络合剂会降低纳米粒子的收率．

英文摘要：

Nano-sized cobalt particles with the diameter of 2 nm were prepared via an organic colloidal process, with sodium formate, ethylene glycol and sodium citrate respectively as the reducing agent, the solvent and the complexing agent. The effects of sodium citrate addition on the yield, crystal structure, particle size and size distribution of the prepared nano-sized cobalt particles were then investigated. The results show that the average particle diameter decreases from 200 nm to 2 nm when the molar ratio of sodium citrate to cobalt chloride changes from 0 to 6, that the sodium citrate plays a crucial role in the controlling of size distribution of the nano-sized particles, and that the size distribution of the particles without sodium citrate addition ranges from tens of nanometers to 300 or 400 nm, while that with sodium citrate addition is limited in the range of （2±0.25） nm. Moreover, it is found that the addition of sodium citrate as a complexing agent may decrease the yield of the nano-sized cobalt particles.