碳/四氧化三铁纳米复合材料合成研究

Study on preparation of nano-sized carbon/ferroferric oxide composite material

为提高四氧化三铁纳米粒子的催化活性和稳定性,采用均匀沉淀方法制备了活性炭/四氧化三铁(AC/Fe3O4)粒子和碳纳米管/四氧化三铁(CNTs/Fe3O4)粒子两种复合材料,利用扫描电子显微镜(SEM)、X射线衍射分析(XRD)以及热重分析(TGA)对复合粒子进行了表征,并测定了它们的电化学性能。研究结果表明:采用该方法制备的四氧化三铁粒子纯度高、大小均匀,粒径在40～100nm;CNTs/Fe3O4中的四氧化三铁粒子粒径较AC/Fe3O4中的更小;经过超声波作用后CNTs/Fe3O4的稳定性较好,而AC/Fe3O4的稳定性很差;两种复合材料均能改善镧镁镍合金的放电比容量和稳定性。

Two kinds of ferroferric oxide （ Fe3 O4 ） nanocomposites namely the active carbon/ferroferric oxide （ AC/ Fe3O4 ） and carbon nanotubes/ferroferric oxide （CNTs/Fe3O4） were prepared by homogenous precipitation method in order to improve catalytic activity and stability of Fe3O4 nano-particles. Composite particles were characterized by the means of scanning electronic microscope （SEM） , X - ray diffraction （ XRD ） , and thermogravimetic analysis （ TGA ） and their electroehemical properties were investigated. Results showed that the obtained Fe3O4 particles had high purity and were well distributed in the particle size range of 40 - 100 nm. After ultrasonic treatment, CNTs/Fe3O4 composite was more stable than AC/Fe3O4 composite. Fe3O4 particles in CNTs/Fe3 O4 composite were smaller than that in AC/Fe3 04 composite. Both composites had improved discharge capacity and stability of LaMgNi4 alloy.