Facile Synthesis of Novel Heterostructure Based on SnO2 Nanorods Grown on Submicron Ni Walnut with Tunable Electromagnetic Wave Absorption Capabilities

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• 作者：Biao Zhao ; Bingbing Fan ; Gang Shao ; Wanyu Zhao ; Rui Zhang
• 刊名：ACS Applied Materials & Interfaces
• 出版年：2015
• 出版时间：August 26, 2015
• 年：2015
• 卷：7
• 期：33
• 页码：18815-18823
• 全文大小：636K
• ISSN：1944-8252

文摘

In this work, the magnetic鈥揹ielectric core-shell heterostructure composites with the core of Ni submicron spheres and the shell of SnO₂ nanorods were prepared by a facile two-step route. The crystal structure and morphology were investigated by X-ray diffraction analysis, transmission electron microscopy (TEM), and field emission scanning electron microscopy (FESEM). FESEM and TEM measurements present that SnO₂ nanorods were perpendicularly grown on the surfaces of Ni spheres and the density of the SnO₂ nanorods could be tuned by simply varying the addition amount of Sn²⁺ in this process. The morphology of Ni/SnO₂ composites were also determined by the concentration of hydrochloric acid and a plausible formation mechanism of SnO₂ nanorods-coated Ni spheres was proposed based on hydrochloric acid concentration dependent experiments. Ni/SnO₂ composites exhibit better thermal stability than pristine Ni spheres based on thermalgravimetric analysis (TGA). The measurement on the electromagnetic (EM) parameters indicates that SnO₂ nanorods can improve the impedance matching condition, which is beneficial for the improvement of electromagnetic wave absorption. When the coverage density of SnO₂ nanorod is in an optimum state (diameter of 10 nm and length of about 40鈥?0 nm), the optimal reflection loss (RL) of electromagnetic wave is 鈭?5.0 dB at 13.9 GHz and the effective bandwidth (RL below 鈭?0 dB) could reach to 3.8 GHz (12.3鈥?6.1 GHz) with the absorber thickness of only 1.8 mm. By changing the loading density of SnO₂ nanorods, the best microwave absorption state could be tuned at 1鈥?8 GHz band. These results pave an efficient way for designing new types of high-performance electromagnetic wave absorbing materials.