Facile synthesis of yolk–shell Ni@void@SnO₂(Ni₃Sn₂) ternary composites via galvanic replacement/Kirkendall effect and their enhanced microwave absorption properties

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• 作者：Biao Zhao ; Xiaoqin Guo ; Wanyu Zhao ; Jiushuai Deng ; Bingbing Fan ; Gang Shao…
• 关键词：yolk–shell ; Ni@void@SnO2(Ni3Sn2) ; galvanic replacement ; Kirkendall effect ; microwave absorption
• 刊名：Nano Research
• 出版年：2017
• 出版时间：January 2017
• 年：2017
• 卷：10
• 期：1
• 页码：331-343
• 全文大小：
• 刊物类别：Chemistry and Materials Science
• 刊物主题：Nanotechnology; Materials Science, general; Atomic/Molecular Structure and Spectra; Condensed Matter Physics; Biotechnology; Biomedicine, general;
• 出版者：Tsinghua University Press
• ISSN：1998-0000
• 卷排序：10

文摘

Yolk–shell ternary composites composed of a Ni sphere core and a SnO₂(Ni₃Sn₂) shell were successfully prepared by a facile two-step method. The size, morphology, microstructure, and phase purity of the resulting composites were characterized by scanning electron microscopy, energy dispersive X-ray spectroscopy, transmission electron microscopy (TEM), high-resolution TEM, selected-area electron diffraction, and powder X-ray diffraction. The core sizes, interstitial void volumes, and constituents of the yolk–shell structures varied by varying the reaction time. A mechanism based on the time-dependent experiments was proposed for the formation of the yolk–shell structures. The yolk–shell structures were formed by a synergistic combination of an etching reaction, a galvanic replacement reaction, and the Kirkendall effect. The yolk–shell ternary SnO₂ (Ni₃Sn₂)@Ni composites synthesized at a reaction time of 15 h showed excellent microwave absorption properties. The reflection loss was found to be as low as–43 dB at 6.1 GHz. The enhanced microwave absorption properties may be attributed to the good impedance match, multiple reflections, the scattering owing to the voids between the core and the shell, and the effective complementarities between the dielectric loss and the magnetic loss. Thus, the yolk–shell ternary composites are expected to be promising candidates for microwave absorption applications, lithium ion batteries, and photocatalysis.