固相合成Co_3O_4纳米晶及晶化动力学研究  

Solid-state Synthesis of Cobalt Oxide (Co_3O_4) Nanocrystallites and Crystallization Kinetics During Thermal Treatment

作　　者：杨华明[1] 李云龙[2] 唐爱东[1] 张向超[1] 周灿伟[1] 

机构地区：[1]中南大学资源生物学院无机材料系,湖南长沙410083 [2]长沙大学,湖南长沙410003

出　　处：《材料热处理学报》2005年第4期1-4,共4页Transactions of Materials and Heat Treatment

基　　金：国家自然科学基金资助项目(50304014);湖南省科技攻关计划资助项目(03GKY3038);中南大学研究生教育创新工程资助项目(030702);长沙大学科学技术研究基金资助项目(SF030302)

摘　　要：以Co(NO3)2·6H2O和NH4HCO3为原料,利用固相反应合成无定形前驱体,再经焙烧合成Co3O4纳米晶。用X射线衍射(XRD)分析了不同焙烧温度对合成Co3O4晶粒尺寸的影响。研究结果表明:按Scherrer公式估算合成Co3O4纳米晶的晶粒尺寸在10～40nm,焙烧温度越高,晶粒尺寸越大;根据前驱体不同升温速率下的差热(DTA)曲线,用Kissinger和Ozawa法计算合成Co3O4纳米晶的活化能分别为132.77kJmol和141.17kJmol,差别不大;根据晶粒生长动力学理论计算Co3O4晶粒长大的活化能为15.44kJmol,表明热处理过程Co3O4纳米晶粒的长大主要以界面扩散为主。Nanocrystalline cobalt oxide (Co3O4) was successfully synthesized after thermal treatment of the precursor obtained by solid-state reaction of Co(NO3)2 &middot 6H2O and NH4HCO3. The crystallization kinetics of Co3O4 nanoparticles was investigated by differential thermal analysis (DTA). The variation of the Co3O4 nanoparticle size with calcination temperature was investigated using X-ray diffraction (XRD) technique. The mechanism for the nanocrystallite growth was primarily investigated. The results indicate that the prepared Co3O4 has a nanocrystalline structure with average crystal size of 10-40 nm, which varies with the calcination temperature. The apparent activation energies of Co3O4 nanocrystallite formation after heating the precursor are analyzed using Kissinger and Ozawa methods, the values are 132.77 kJ/mol and 141.17 kJ/mol, respectively. The activation energy for the nanocrystallite growth is calculated to be 15.44 kJ/mol according to kinetics theory of nanocrystallite growth, indicating that Co3O4 nanocrystallite grows primarily by means of an interfacial reaction during the thermal treatment.

关 键 词：四氧化三钴(Co3O4) 纳米晶 固相合成 动力学 活化能 

分 类 号：TM27[一般工业技术—材料科学与工程]