Excellent electromagnetic wave absorption properties of porous core-shell CoO/Co@C nanocomposites derived from a needle-shaped Co(OH)2@ZIF-67 template
| Autor: | Xiyue Zhang, Panpan Zhou, Meng Wang, Gui-Hua Qiu, Lixi Wang, Xiaokang Wang, Qitu Zhang, Zhihao Liu |
|---|---|
| Rok vydání: | 2020 |
| Předmět: |
Nanocomposite
Materials science Mechanical Engineering Reflection loss Metals and Alloys 02 engineering and technology engineering.material 010402 general chemistry 021001 nanoscience & nanotechnology 01 natural sciences 0104 chemical sciences law.invention Chemical engineering Coating Mechanics of Materials law Materials Chemistry engineering Calcination 0210 nano-technology Porosity Absorption (electromagnetic radiation) Pyrolysis Microwave |
| Zdroj: | Journal of Alloys and Compounds. 842:155807 |
| ISSN: | 0925-8388 |
| DOI: | 10.1016/j.jallcom.2020.155807 |
| Popis: | Metal-organic-frameworks (MOFs) have attracted wide attention in the preparation of microwave absorbing materials because of their developed abundant porous structures. Compositing magnetic oxide into MOFs could significantly enhance the microwave absorption ability. In this work, a CoO/Co@C nanocomposite was prepared by calcining a needle-shaped Co(OH)2@ZIF-67 template at different pyrolysis temperatures (500–650 °C). Furthermore, CoO and Co particles were embedded into porous carbon frameworks, creating ample surfaces and interfaces. The core-shell and porous structure is beneficial to microwave absorption (MA). In addition, it is obvious that the calcination temperature has a significant impact on the microwave absorption properties of the samples. In detail, when the calcination temperature is 550 °C, the samples exhibit the best microwave absorption properties. A minimum reflection loss (RLmin) of −38.46 dB is obtained at 16.12 GHz with a coating thickness of 1.5 mm, and the maximum effective absorption bandwidth (RL ≤ −10 dB) can reach 4.8 GHz (9.68–14.48 GHz) at a coating thickness of 2 mm. Such excellent MA properties are attributed to the outstanding magnetoelectric synergistic effect and well-matched impedance. |
| Databáze: | OpenAIRE |
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