引用本文:
【打印本页】   【HTML】   【下载PDF全文】   View/Add Comment  【EndNote】   【RefMan】   【BibTex】
←前一篇|后一篇→ 过刊浏览    高级检索
本文已被:浏览 1990次   下载 825 本文二维码信息
码上扫一扫!
分享到: 微信 更多
Convenient Approach to °-Fe2O3 Nanoparticles: Magnetic and Electrochemical Properties
Bei-bei Li1, Ming-rong Ji*1, Xiao-min Ni2, Fu Zhou2, Dong-en Zhang2, Jing Cheng2
1.Hefei National Laboratory for Physical Sciences at Microscale, University of Science and Technology of China, Hefei 230026, China;2.Department of Chemistry, University of Science and Technology of China, Hefei 230026, China
Abstract:
A convenient approach is reported for the synthesis of spherical maghemite (°-Fe2O3) nanoparticles. The process was realized by the controlled oxidation of Fe3O4 precursor, which originated from a facile partialreduction co-precipitation process. The starting material of hydrosulfurous sodium (Na2S2O4), which can allow reaction to proceed without any deoxygenated protection, was proven to be important in the formation of the precursor. A series of techniques, including X-ray diffraction, transmission electron microscopy and a vibrating sample magnetometer were used to characterize the product. The resultant °-Fe2O3 nanoparticles exhibited ferromagnetism at 300 K and the values of saturation magnetization and coercivity were 70 emu/g and 164 Oe, respectively. The electrochemical properties of lithium ions intercalation into °-Fe2O3 nanoparticles were tested in Te°on cells. A specific capacity of 933 mAh/g was delivered at a current density of 0.2 mA/cm2 (voltage range 3.0-0.3 V vs. Li), corresponding to the reaction of 5.7 Li+ per Fe2O3. A possible mechanism of the reaction of lithium with maghemite spinel was discussed.
Key words:  Magnetic materials, Chemical synthesis, Electrochemical properties
FundProject:
简单的方法制备°-Fe2O3纳米粒子及其磁性质和电化学性质
李蓓蓓 1, 季明荣 * 1, 倪小敏 2, 周复 2, 张东恩 2, 程静 2
1.中国科学技术大学 合肥微尺度物质科学国家实验室,合肥 230026;2.中国科学技术大学 化学系,合肥 230026
摘要:
报道了制备磁性Fe2O3纳米粒子的一种简单易行的方法.利用部分还原共沉淀法, 以Na2S2O4作为还原剂, 用FeCl3先制备出Fe2O3纳米微粒, 再在空气中直接煅烧, 成功地制备出粒径较均匀(约13 nm)的磁性Fe2O3微粒. 实验发现Na2S2O4在部分还原共沉淀法中起到了去氧剂兼还原剂的特殊作用.研究表明, 样品在室温下具有铁磁性, 其饱和磁化强度和矫顽力分别为70 emu/g和164 Oe; 产物具有好的电化学性质,在3.0?0.3 V(相对于金属锂)、0.2 mA/cm2时,样品的首次放电容量可达到933 mAh/g.同时还讨论了放电过程中金属锂与Fe2O3的反应机理.
关键词:  磁性材料,化学合成,电化学性质
DOI:10.1360/cjcp2007.20(2).203.4
分类号: