Magnetite Nanocrystals on Multiwalled Carbon Nanotubes as a Synergistic Microwave Absorber

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• 作者：Zhijiang Wang ; Lina Wu ; Jigang Zhou ; Wei Cai ; Baozhong Shen ; Zhaohua Jiang
• 刊名：The Journal of Physical Chemistry C
• 出版年：2013
• 出版时间：March 14, 2013
• 年：2013
• 卷：117
• 期：10
• 页码：5446-5452
• 全文大小：433K
• 年卷期：v.117,no.10(March 14, 2013)
• ISSN：1932-7455

文摘

The understanding of the interaction between the building blocks in the hybrids can advance our comprehension of design principles in high-performance microwave absorbing materials. Here, we report a hybrid material consisting of magnetite (Fe₃O₄) nanocrystals grown on multiwalled carbon nanotube (MWCNT) as a high-performance microwave absorber in the 2鈥?8 GHz band, although Fe₃O₄ nanocrystals or MWCNTs alone or their physical mixture show little microwave absorption. The hybrid is characterized by transmission electron microscopy, X-ray diffraction, and vector network analysis, X-ray absorption near-edge structures at the C K-edge and Fe L_3,2-edge, and electron spin resonance analysis. Microstructural analysis reveals that Fe₃O₄ nanocrystals are immobilized on the MWCNT surface by a strong interaction. Charges in the MWCNT/Fe₃O₄ hybrids transfer from the conduction band in Fe₃O₄ to C 2p-derived states in the MWCNT substrate. Dipole interaction between the magnetic nanocrystals is increased. The synergetic interactions leads to much improved microwave absorption.