湿化学还原法合成Co纳米粒子的研究

Synthesis of Cobalt Nanoparticles by Wet Chemical Reduction Process

对水合联氨溶液直接还原法制备金属钴粉作了热力学分析并进行了实验研究，采用EDTA容量滴定分析法、X射线衍射分析（XRD）、扫描电子显微镜（SEM）、透射电子显微镜（TEM）对钴粉的纯度、形貌、粒度及晶型进行分析表征，结果表明：在氯化钴溶液体系中，以水合联氨为还原剂，硼氢化钾为晶核引发剂，柠檬酸钠为络合剂，可制备纯度为99．5％、粒径为5-15nm的纳米金属钴粉。钴粉为混晶型产物，分别为密排六方晶型（HCP）和面心立方晶型（FCC）。

The cobalt （Co） powder is prepared under a direct reduction process in hydrazine hydrate alkaline system and the thermodylaamic mechanism is investigated. Characterizations of the obtained Co powder including its purity, phase composition, morphological structure and the particle size are evaluated by EDTA titration analysis, X-ray diffraction determination, and electronic microscope （SEM and TEM） observation, respectively. Results show that the cobalt nanoparticles with 99.5% in purity and 5-15nm in size is synthesized in cobalt chloride solution with hydrazine hydrate as the reductive agents, and potassium borohydride as the nucleating agent and sodium citrate as the complexant. The resulting Co powder possess two mixed phases of HCP phase and FCC phase.