丁建芳
,
姜继森
无机材料学报
doi:10.3724/SP.J.1077.2007.00859
以常见的表面活性剂油酸钠作为表面改性剂, 通过油酸根离子中的脂肪烃链与高温油相法制备的Fe3O4纳米粒子表面的亲油性基团之间的范德华力作用, 将分散在油相中的Fe3O4纳米粒子转移到水相中. 研究了油酸钠浓度、油相中Fe3O4纳米粒子含量、pH值及温度等条件对改性结果的影响; 用穆斯堡尔谱仪(Mossbauer)、透射电镜(TEM)、傅立叶红外光谱(FT-IR)等方法对改性前后的样品进行了表征. 结果表明: 本方法可有效地将油相法制备的Fe3O4纳米粒子从油相中转移到水相. 当油酸钠浓度为3mmol/L、Fe3O4纳米粒子在正己烷中浓度为12.28mg·mL-1、 pH为8.6且温度为60℃时, 转移率最高可达86％, 改性后粒子在水相中的含量最高可达10.5mg·mL-1; 改性后磁性粒子在水相中含量较低时, 能够稳定分散较长时间.
关键词:
油酸钠
,
Fe3O4
,
nanoparticles
,
surface modification
王卫伟
,
许英伟
,
杜健
,
张爱娟
,
姚佳良
人工晶体学报
分别采用两种方式(一步合成法和二步合成法)在Fe3O4表面生长层状双金属氢氧化物(LDHs),得到了Fe3O4/LDHs复合材料.利用X-射线衍射、电子显微分析、红外光谱和交变梯度磁强计等测试方法研究了LDHs和Fe3O4的复合方式对复合材料形貌、粒径、结晶性、磁性能和吸附性能的影响.同时对比分析了LDHs和Fe3O4/LDHs复合材料对Cr(Ⅵ)离子的平衡吸附规律.结果表明,采用一步合成法制备的Fe3O4/LDHs复合材料具有良好的磁性能和吸附性能.
关键词:
层状双金属氢氧化物(LDHs)
,
Fe3O4
,
复合结构
,
吸附性能
Y.X. Chen L.H. He P.J. Shang Q.L. Tang Z.Q. Liu H.B. Liu L.P. Zhou
材料科学技术（英文）
Micro-sized (1030.3§178.4 nm) and nano-sized (50.4±8.0 nm) Fe3O4 particles have been fabricated through hydrogen thermal reduction of α-Fe2O3 particles synthesized by means of a hydrothermal process. The morphology and microstructure of the micro-sized and the nano-sized Fe3O4 particles were characterized by X-ray diffraction, field-emission gun scanning electron microscopy, transmission electron microscopy and high-resolution electron microscopy. The micro-sized Fe3O4 particles exhibit porous structure, while the nano-sized Fe3O4 particles are solid structure. Their electrochemical performance was also evaluated. The nano-sized solid Fe3O4 particles exhibit gradual capacity fading with initial discharge capacity of 1083.1 mAhg¡1 and reversible capacity retention of 32.6% over 50 cycles. Interestingly, the micro-sized porous Fe3O4 particles display very stable capacity-cycling behavior, with initial discharge capacity of 887.5 mAhg¡1 and charge capacity of 684.4 mAhg−1 at the 50th cycle. Therefore, 77.1% of the reversible capacity can be maintained over 50 cycles. The micro-sized porous Fe3O4 particles with facile synthesis, good cycling performance and high capacity retention are promising candidate as anode materials for high energy-density lithium-ion batteries.
关键词:
Lithium-ion battery
,
null
,
null
Y.X. Chen L.H. He P.J. Shang Q.L. Tang Z.Q. Liu H.B. Liu L.P. Zhou
材料科学技术（英文）
Micro-sized (1030.3§178.4 nm) and nano-sized (50.4±8.0 nm) Fe3O4 particles have been fabricated through hydrogen thermal reduction of α-Fe2O3 particles synthesized by means of a hydrothermal process. The morphology and microstructure of the micro-sized and the nano-sized Fe3O4 particles were characterized by X-ray diffraction, field-emission gun scanning electron microscopy, transmission electron microscopy and high-resolution electron microscopy. The micro-sized Fe3O4 particles exhibit porous structure, while the nano-sized Fe3O4 particles are solid structure. Their electrochemical performance was also evaluated. The nano-sized solid Fe3O4 particles exhibit gradual capacity fading with initial discharge capacity of 1083.1 mAhg¡1 and reversible capacity retention of 32.6% over 50 cycles. Interestingly, the micro-sized porous Fe3O4 particles display very stable capacity-cycling behavior, with initial discharge capacity of 887.5 mAhg¡1 and charge capacity of 684.4 mAhg−1 at the 50th cycle. Therefore, 77.1% of the reversible capacity can be maintained over 50 cycles. The micro-sized porous Fe3O4 particles with facile synthesis, good cycling performance and high capacity retention are promising candidate as anode materials for high energy-density lithium-ion batteries.
关键词:
Lithium-ion battery
,
null
,
null
