分别采用乙醇、乙二醇和丙三醇为钴离子溶剂,用水合肼在室温下还原钴盐制备钴粉,研究了不同钴离子溶剂对所制备钴粉形貌的影响及其机理。研究结果表明:所制备的钴粉均由FCC和HCP两相混合组成。以乙醇为钴离子溶剂,当钴离子的浓度足够低...分别采用乙醇、乙二醇和丙三醇为钴离子溶剂,用水合肼在室温下还原钴盐制备钴粉,研究了不同钴离子溶剂对所制备钴粉形貌的影响及其机理。研究结果表明:所制备的钴粉均由FCC和HCP两相混合组成。以乙醇为钴离子溶剂,当钴离子的浓度足够低时(0.045 mol/L),出现树枝状的颗粒,其余钴离子浓度下,原生钴颗粒形貌为类球形。采用多元醇(乙二醇、丙三醇)为钴离子溶剂时,由于一定量的多元醇会聚集形成微反应器,有利于表面光滑的球形原生钴粉颗粒生成。乙醇的添加量通过影响晶核的形核、生长、扩散等过程来影响产物形貌。多元醇的添加量主要通过影响溶液的黏度和微反应器的完整性和数量等来影响产物的形貌。乙二醇的添加量在80 m L时,获得了均匀的、表面光滑的球形钴粉颗粒。展开更多
Spherical cobalt carbonate with high tap density, good crystallization and uniform particle size was prepared by controlled chemical crystal method using cobalt chloride and ammonium bicarbonate as cobalt source and p...Spherical cobalt carbonate with high tap density, good crystallization and uniform particle size was prepared by controlled chemical crystal method using cobalt chloride and ammonium bicarbonate as cobalt source and precipitator. The effects of pH value and reaction time on crystallization and physical properties of cobalt carbonate were studied. The results show that the key factors influencing the preparation process of spherical cobalt carbonate with high tap density and good crystallization are how to control pH value (7.25±0.05) and keep some reaction time (about 10 h). Co4O3 was prepared by sintering spherical morphology CoCO3 samples at varied temperatures. The results show that as the decomposition temperature increases, the as-obtained Co4O3 products with porous structure transform into polyhedral structure with glazed surface, and simultaneously the cobalt content and tap density increase. However, the specific surface area shows a trend of decrease.展开更多
文摘分别采用乙醇、乙二醇和丙三醇为钴离子溶剂,用水合肼在室温下还原钴盐制备钴粉,研究了不同钴离子溶剂对所制备钴粉形貌的影响及其机理。研究结果表明:所制备的钴粉均由FCC和HCP两相混合组成。以乙醇为钴离子溶剂,当钴离子的浓度足够低时(0.045 mol/L),出现树枝状的颗粒,其余钴离子浓度下,原生钴颗粒形貌为类球形。采用多元醇(乙二醇、丙三醇)为钴离子溶剂时,由于一定量的多元醇会聚集形成微反应器,有利于表面光滑的球形原生钴粉颗粒生成。乙醇的添加量通过影响晶核的形核、生长、扩散等过程来影响产物形貌。多元醇的添加量主要通过影响溶液的黏度和微反应器的完整性和数量等来影响产物的形貌。乙二醇的添加量在80 m L时,获得了均匀的、表面光滑的球形钴粉颗粒。
文摘Spherical cobalt carbonate with high tap density, good crystallization and uniform particle size was prepared by controlled chemical crystal method using cobalt chloride and ammonium bicarbonate as cobalt source and precipitator. The effects of pH value and reaction time on crystallization and physical properties of cobalt carbonate were studied. The results show that the key factors influencing the preparation process of spherical cobalt carbonate with high tap density and good crystallization are how to control pH value (7.25±0.05) and keep some reaction time (about 10 h). Co4O3 was prepared by sintering spherical morphology CoCO3 samples at varied temperatures. The results show that as the decomposition temperature increases, the as-obtained Co4O3 products with porous structure transform into polyhedral structure with glazed surface, and simultaneously the cobalt content and tap density increase. However, the specific surface area shows a trend of decrease.
