化学学报 ›› 2007, Vol. 65 ›› Issue (18): 2069-2075. 上一篇    下一篇

研究论文

NiO纳米片和多孔纳米片自组装的空心微球的无模板水热法制备与磁学性质

张建英1, 杨合情*,1, 宋玉哲1, 陈迪春2, 李丽1, 焦华1, 王林芳1   

  1. (1陕西师范大学化学与材料科学院大分子科学陕西省重点实验室 西安 710062)
    (2西安理工大学现代材料分析与测试中心 西安 710048)
  • 投稿日期:2007-01-19 修回日期:2007-04-14 发布日期:2007-09-28
  • 通讯作者: 杨合情

Template-free Hydrothermal Synthesis and Magnetic Properties of Hollow Microspheres Co-constructed with NiO Nanosheets and Porous Nanosheets

ZHANG Jian-Ying1; YANG He-Qing*,1; SONG Yu-Zhe1; CHEN Di-Chun2; LI Li1 JIAO Hua1; WANG Ling-Fang1   

  1. (1 Key Laboratory of Macromolecular Science of Shaanxi Province, School of Chemistry and Materials Science, Shaanxi Normal University, Xi'an 710062)
    (2 Advanced Material Analysis and Test Center, Xi'an University of Technology, Xi'an 710048)
  • Received:2007-01-19 Revised:2007-04-14 Published:2007-09-28
  • Contact: YANG He-Qing

报道一种非常简单的制备NiO和Ni(OH)2空心微球的无模板水热法, 即通过NiCl2与氨水在140 ℃水热反应12 h, 制备了Ni(OH)2纳米片自组装的空心微球, 经400 ℃热处理2 h得到了NiO空心微球. 采用X射线衍射仪、扫描电镜和透射电子显微镜对产物进行表征, 并在室温下测试了它的磁学性能, 结果表明, Ni(OH)2空心微球的直径约为3~4 μm, 它是由尺寸1.1~1.3 μm左右的六方相结构的Ni(OH)2纳米片组装而成; NiO空心微球是由立方相纳米片和多孔纳米片组装而成, 它具有弱的铁磁性, 其矫顽力为583 Oe, 剩余磁化强度为0.213 emu/g. 研究了氨在Ni(OH)2纳米片的形成与组装过程中的作用, 提出了可能的生长机理.

关键词: NiO, Ni(OH)2, 空心微球, 水热法, 磁学性质

In this work, we report a very simple template-free hydrothermal approach to prepare hollow Ni(OH)2 and NiO microspheres. The hollow Ni(OH)2 microspheres were prepared via the hydrothermal reaction of NiCl2 with aqueous ammonia at 140 ℃ for 12 h. Subsequently, the similar microstructured NiO hollow microspheres were obtained by calcining the above precursor at 400 ℃ for 2 h. The as-synthesized products were characterized by means of powder X-ray diffraction, scanning electron microscopy and transmission electron microscopy. The results showed that the hollow Ni(OH)2 microspheres with the diameters of 3~4 μm are constructed from 2-dimensional Ni(OH)2 nanosheets with the hexagonal structure and dimensions of 1.1~1.3 μm. The hollow NiO microspheres are co-constructed from NiO nanosheets and porous nanosheets with the cubic structure. Magnetic properties of the hollow NiO microspheres have been detected by a vibrating sample magnetometer at room temperature. It was found that the NiO microspheres exhibit weak ferromagnetism. The coercive force and remanent magnetization are 583 Oe and 0.213 emu/g respectively. The role of the ammonia in the growth and self-assembly of Ni(OH)2 nanosheets was investigated, and a possible mechanism was also proposed to account for the formation and conversion of Ni(OH)2 nanosheet-based hollow microspheres into NiO hollow microspheres.

Key words: NiO, Ni(OH)2, hollow microsphere, hydrothermal route, ferromagnetism