FeOOH@Fe3O4复合材料合成及超级电容特性研究

以FeOOH为基质,氯化铁为铁源,通过溶剂热法制备得到包覆四氧化三铁的氧化铁黄。分别采用粉末X射线衍射(XRD)、扫描电镜(SEM)和热重-差热分析(TG-DTA)等技术对包覆层物质及复合产物的结构和性质进行表征。结果表明:通过溶剂热法合成的复合产物表层是四氧化三铁结构,内部为羟基氧化铁。电化学测试结果表明FeOOH@Fe3O4在0.1A·g-1电流密度下比容量为89F·g^-1,在该电流密度下循环800次,容量维持在80%左右,优于FeOOH和Fe3O4;FeOOH@Fe3O4复合产物的比表面积为17.08m^2·g^-1,且FeOOH@Fe3O4电极内阻为1.45Ω,低于FeOOH和Fe3O4,这主要是由于FeOOH@Fe3O4有效结合了FeOOH比表面积大和四氧化三铁导电性高的优势,扩大了电解液离子与电极活性物质的接触面积,提高了电子和离子在电极材料中的传递速率。

Synthesis of FeOOH@Fe3O4 Composite and its Super Capacitance Properties

FeOOH coated with ferric oxide was prepared by solvothermal method using ferric chloride as iron source and ferric oxide yellow as matrix.The structure and properties of the coating layer and their composites were characterized by powder X-ray diffraction(XRD),scanning electron microscopy(SEM)and thermogravimetric-differential thermal analysis(TG-DTA).The results show that the surface of the composite product synthesized by solvothermal method is ferric oxide structure,and the interior is ferric hydroxide.The results of electrochemical tests show that the specific capacity of FeOOH@Fe3O4 is 89F·g^-1 at 0.1A·g^-1.The capacity of FeOOH@Fe3O4 is maintained at about 80%for 800 cycles,which is better than FeOOH and Fe3O4.The specific surface area of FeOOH@Fe3O4 is 17.08m^2·g^-1.In addition,the internal resistance of FeOOH@Fe3O4 electrode is 1.45Ω,lower than FeOOH and Fe3O4,mainly because FeOOH@Fe3O4 effectively combines the advantages of large specific surface area of FeOOH and high conductivity of ferric oxide,which enlarges the electric performance.The contact area between the electrolyte ion and the active material of the electrode improves the transfer rate of electrons and ions in the electrode material.