ZnCo_2O_4尖晶石纳米粉体的新型共沉淀法合成及表征  

Preparation and Characterization of the Spinel Oxide ZnCo_2O_4 Obtained by Novel Coprecipitation Method

作　　者：韦秀华[1] 魏敏[1] 陈栋华[2] 

机构地区：[1]商丘师范学院化学系,河南商丘476000 [2]中南民族大学化学与材料科学学院,湖北武汉430074

出　　处：《信阳师范学院学报（自然科学版）》2007年第3期341-345,共5页Journal of Xinyang Normal University(Natural Science Edition)

基　　金：湖北省自然科学基金重点资助项目(2001ABA009)

摘　　要：以草酸为沉淀剂、乙醇为溶剂，通过新型共沉淀法合成分子前躯体锌钴草酸复合盐ZnCO2（C2O4）3·4H2O，对该前躯体在不同温度下热处理即可制得锌钴尖晶石粉体．利用热重分析仪（TGA）和差示扫描量热仪（DSC）对前躯体热分解过程分别进行热失重分析和动力学分析．结果表明，前躯体热分解仅经历2个热失重过程（脱结晶水和最后分解）且最后分解过程遵循随机成核和核随后生长单一的动力学机理，活化能不随转化率的变化而变化．由此说明前驱体为草酸复合盐而不是二元混合盐．利用X-射线衍射（XRD）、红外光谱（IR）和透射电子显微镜（TEM）等分析手段对尖晶石粉体进行表征．结果显示，前躯体在低温段450—650℃煅烧2h即可获得单相、颗粒细小均匀的尖晶石粉体，高温750℃煅烧，得到ZnO和缺锌的锌钴尖晶石的混合物，The zinc-cobalt-oxide spinel was obtained by the calcination of the molecular precursor at different temperature, namely, zinc cobalt oxalate [ ZnCo2 （ C2O4 ） 3 · 4H2O ] prepared by novel coprecipitation method using oxalic acid as precipitator and ethanol as solvent. The thermal weight loss analysis and kinetics analysis of the decomposition process of the precursor were performed on a Thermogravimetry analyzer （TGA） and Differential scanning calorimeter （DSC）. The results showed that the weight loss occurs only two steps （ elimination of the hydrated water and last decomposition）, the last decomposition process followed single kinetics mechanism -nucleation and growth mechanism and the activation energy hardly varies with the extent of conversion, which revealed that the precursor is not mixed oxalate but zinc cobalt oxalate. The ZnCo2O4 spinel powder has been characterized by X-ray powder diffraction （XRD）, Infrared spectra （IR） and Transmission electron microscope （TEM）. It was shown that single phase and thin spinel powder is formed after calcination between 450 and 650 ℃, and calcinated at 750 ℃, a mixture of ZnO and Zn-Co spinel containing fewer zinc cations was obtained.

关 键 词：共沉淀 尖晶石 钴酸锌 热分析动力学 X射线衍射 

分 类 号：TB383[一般工业技术—材料科学与工程]