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(zhì)界面有利于增強(qiáng)材料的界面極化效應(yīng)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(zhàn)。本論文通過犧牲模板法和水熱反應(yīng)的協(xié)同制備了兼具多異質(zhì)界面和空腔結(jié)構(gòu)的三明治夾層NC@Co/NC@MnO2復(fù)合材料。中間層的磁性組分（Co/NC）被內(nèi)層的摻氮碳（NC）和外層的二氧化錳納米片包裹，該異質(zhì)界面和空腔結(jié)構(gòu)使材料在較低填充量下實(shí)現(xiàn)了對(duì)電磁波吸強(qiáng)度收的擴(kuò)寬。當(dāng)厚度為2.5 mm時(shí)，三明治夾層NC@Co/NC@MnO2復(fù)合材料的最大反射損耗為-44.8 dB，有效帶寬在2.3 mm處達(dá)到9.6 GHz。該結(jié)果為利用界面工程和空心結(jié)構(gòu)制備高效電磁波吸收劑提供了一種新的思路。
論文亮點(diǎn)
1.提出一種將犧牲模板法和水熱合成反應(yīng)相結(jié)合合成了一種具有三明治夾層結(jié)構(gòu)的NC@Co/NC@MnO2復(fù)合材料。
2. 空心結(jié)構(gòu)使材料具有填充量低的特性，多異質(zhì)界面可以顯著增強(qiáng)材料的界面極化，兩者之間的協(xié)同效應(yīng)有利于增強(qiáng)多重?fù)p耗衰減，提高其吸波性能。
3. 當(dāng)填充量為20%時(shí)，NC@Co/NC@MnO2在厚度為2.5mm時(shí)具有最好的吸波性能，其吸波強(qiáng)度可達(dá)-44.8dB，有效頻帶寬度在厚度為2.3mm為9.6 GHz。
第一作者：衛(wèi)琛浩
郵箱：weich_edu@163.com