Preparation of Honeycomb SnO2 Foams and Configuration-Dependent Microwave Absorption Features

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• 作者：Biao Zhao ; Bingbing Fan ; Yawei Xu ; Gang Shao ; Xiaodong Wang ; Wanyu Zhao ; Rui Zhang
• 刊名：ACS Applied Materials & Interfaces
• 出版年：2015
• 出版时间：December 2, 2015
• 年：2015
• 卷：7
• 期：47
• 页码：26217-26225
• 全文大小：652K
• ISSN：1944-8252

文摘

Ordered honeycomb-like SnO₂ foams were successfully synthesized by means of a template method. The honeycomb SnO₂ foams were analyzed by X-ray diffraction (XRD), thermogravimetric and differential scanning calorimetry (TG-DSC), laser Raman spectra, scanning electron microscopy (SEM), and Fourier transform infrared (FT-IR). It can be found that the SnO₂ foam configurations were determined by the size of polystyrene templates. The electromagnetic properties of ordered SnO₂ foams were also investigated by a network analyzer. The results reveal that the microwave absorption properties of SnO₂ foams were dependent on their configuration. The microwave absorption capabilities of SnO₂ foams were increased by increasing the size of pores in the foam configuration. Furthermore, the electromagnetic wave absorption was also correlated with the pore contents in SnO₂ foams. The large and high amounts pores can bring about more interfacial polarization and corresponding relaxation. Thus, the perfect ordered honeycomb-like SnO₂ foams obtained in the existence of large amounts of 322 nm polystyrene spheres showed the outstanding electromagnetic wave absorption properties. The minimal reflection loss (RL) is 鈭?7.6 dB at 17.1 GHz, and RL less than 鈭?0 dB reaches 5.6 GHz (12.4鈥?8.0 GHz) with thin thickness of 2.0 mm. The bandwidth (<鈭?0 dB, 90% microwave dissipation) can be monitored in the frequency regime of 4.0鈥?8.0 GHz with absorber thickness of 2.0鈥?.0 mm. The results indicate that these ordered honeycomb SnO₂ foams show the superiorities of wide-band, high-efficiency absorption, multiple reflection and scatting, high antioxidation, lightweight, and thin thickness.