锌掺杂对针状氧化铁的结构及电化学性能的影响

Effect of Doping Zinc Ion on Structure and Electrochemical Properties of Needle-like Iron Oxide Nanoparticles

采用微乳–超临界干燥法制备了Zn2+掺杂针状Zn0.34Fe2.66O4纳米晶。利用红外光谱仪、能谱仪、X射线衍射仪和透射电子显微镜对样品的晶体结构、化学组成、粒径和形貌进行表征。结果表明:产物为形貌规整的针状,长径比明显小于Fe3O4的。通过循环伏安、恒流充放电和交流阻抗等方法研究了Zn0.34Fe2.66O4电极的电化学性能,结果表明:在1mol/L H2SO4溶液中,在0～1.6V(vs饱和甘汞电极)电位范围内,Zn2+掺杂Zn0.34Fe2.66O4材料的电活性和循环稳定性、可逆性优于Fe3O4的。在1A/g电流密度下,单电极比容量达1116F/g,大电流充放电性能良好。

Zn0.34Fe2.66O4 nanocrystallines were synthesized through a microemulsion-alcohol supercritical fluid drying technique. The structure, chemical composition, size and morphology of products were characterized by infrared spectroscopy, energy dispersive X-ray fluoresence spectrometry, X-ray diffraction and transmission electron microscopy. The results show that the as-prepared powder has a regularly needle-like morphology, and the aspect ratio of rod-like Zn0.34Fe2.66O4 microcrystallines is smaller than that of Fe3O4. The electrochemical properties of Zn0.34Fe2.66O4 electrode were investigated by using cyclic voltammetry, galvanostatic charge/discharge and electrochemical impedance spectrometry. It was indicated that Zn0.34Fe2.66O4 nanocrystallines exhibited better electrochemical performance and cycling stability in H2SO4 electrolyte of 1 mol/L in the potential range of 0–1.6 V （vs saturated calomel electrode）. The specific capacitance of the material as a single electrode was 1 116 F/g at the current density of 1 A/g. The sample had a better load discharge performance.