Chenhao Wei, Lingzi Shi, Maoqing Li*, Mukun He, Mengjie Li, Xinrui Jing, Panbo Liu and Junwei Gu*. Hollow engineering of sandwich NC@Co/NC@MnO2 composites toward strong wideband electromagnetic wave attenuation. Journal of Materials Science & Technology, 2024, 175: 194-203. 2023IF=10.9.
https://doi.org/10.1016/j.jmst.2023.08.020
Abstract
Multiple hetero-interfaces would strengthen interfacial polarization and boost electromagnetic wave absorption, but still remain the formidable challenges in decreasing filler loadings. Herein, sandwich NC@Co/NC@MnO2 composites with hollow cavity, multiple hetero-interfaces, and hierarchical structures have been fabricated via the cooperative processes of self-sacrifice strategy and sequential hydrothermal reaction. In the sandwich composites, middle magnetic components (Co/NC) are wrapped by inner N-doped carbon (NC) matrix and outer hierarchical MnO2 nanosheets. Importantly, hollow engineering of sandwich composites with multiple hetero-interfaces greatly facilitates the enhancement of absorption bandwidth without sacrificing the absorption intensity. The maximum reflection loss of sandwich NC@Co/NC@MnO2 composites reaches -44.8 dB at 2.5 mm and the effective bandwidths is achieved as wide as 9.6 GHz at 2.3 mm. These results provide us a new insight into preparing efficient electromagnetic wave absorbers by interface engineering and hollow construction.
多異質界面有利于增強材料的界面極化效應和電磁波吸收特性，但在減少填料填充量方面仍面臨著艱巨的挑戰。本論文通過犧牲模板法和水熱反應的協同制備了兼具多異質界面和空腔結構的三明治夾層NC@Co/NC@MnO2復合材料。中間層的磁性組分（Co/NC）被內層的摻氮碳（NC）和外層的二氧化錳納米片包裹，該異質界面和空腔結構使材料在較低填充量下實現了對電磁波吸強度收的擴寬。當厚度為2.5 mm時，三明治夾層NC@Co/NC@MnO2復合材料的最大反射損耗為-44.8 dB，有效帶寬在2.3 mm處達到9.6 GHz。該結果為利用界面工程和空心結構制備高效電磁波吸收劑提供了一種新的思路。
論文亮點
1.提出一種將犧牲模板法和水熱合成反應相結合合成了一種具有三明治夾層結構的NC@Co/NC@MnO2復合材料。
2. 空心結構使材料具有填充量低的特性，多異質界面可以顯著增強材料的界面極化，兩者之間的協同效應有利于增強多重損耗衰減，提高其吸波性能。
3. 當填充量為20%時，NC@Co/NC@MnO2在厚度為2.5mm時具有最好的吸波性能，其吸波強度可達-44.8dB，有效頻帶寬度在厚度為2.3mm為9.6 GHz。
第一作者：衛琛浩
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