机械固相化学反应制备纳米β-Co粉及其反应热力学研究

State Key Laboratory for Powder Metallurgy, Central South University, Changsha 410083, China

摘要:

以H2C2O4·2H2O及Co(NO3)2·6H2O为原料，在高速球磨中进行固相化学反应，经洗涤并喷雾干燥获得分布均匀的球形纳米晶前驱物，再经高温分解，制备出目标物。对分解产物进行了XRD/SEM分析。结果表明，产物形貌为球形、平均粒径在100 nm左右的纳米粉体，其晶型为面心立方结构β-Co，同时对制备反应进行了热力学的研究

Abstract:

Pure nano-crystalline Co powders of nearly spherical shape have been produced using a high-energy ball mill. This method has used the mechanical force to crush solid reactant, which increased the BET specific surface area and reaction speed of reactant, and accelerated the nucleation rate. The method includes three steps. Firstly, a precursor of CoC2O4 was prepared by the mechano-chemical solid state reaction with H2C2O4·2H2O and Co(NO3)2·6H2O at ambient temperature. Secondly, the precursor CoH2C2O4 powders were dispersed by spray-drying to get the spherical precursor. Finally, Co powders were obtained by decomposition of the precursor CoH2C2O4 for about 3~3.5 h at 450~500 oC. The powders were characterized by X-ray diffractometer and scanning electron microscopy. The results show that spherical, cubic structure, 100 nm β-Co powders were synthesized