Wu Fei, Liu Pei, Wang Jiqi, Shah Tariq, Ahmad Mudasir, Zhang Qiuyu, Zhang Baoliang
School of Chemistry and Chemical Engineering, Northwestern Polytechnical University, Xi'an 710072, China; Xi'an Key Laboratory of Functional Organic Porous Materials, Northwestern Polytechnical University, Xi'an 710129, China.
School of Chemistry and Chemical Engineering, Northwestern Polytechnical University, Xi'an 710072, China.
J Colloid Interface Sci. 2020 Oct 1;577:242-255. doi: 10.1016/j.jcis.2020.05.058. Epub 2020 May 28.
A new type of microwave absorbing material (TCF@FeO@NCLs) with multi-layer heterostructure is designed and fabricated via a one-step pyrolysis process of the precursor (PF@FeO@PDA). PF@FeO@PDA is prepared by the technology of confined self-polycondensation, solvothermal method coupled with polymerization of dopamine (DA). The as-obtained material has the structure of tubular carbon nanofibers (TCF) embedded with FeO nanoparticles, dispersed FeO nanoparticles, and nitrogen-doped carbon layers (NCLs) from inside to outside. Notably, tubular carbon nanofibers provide the major dielectric loss. FeO nanoparticles significantly improve the microwave absorption ability at low frequencies and provide appropriate magnetic loss. NCLs improve the conductivity and facilitate the generation of multiple polarization effects, resulting in enhanced dielectric loss. The absorption mechanism is further elucidated. Based on the synergistic effect of double dielectric/magnetic loss composite materials, the interface introduced by multi-layer heterostructure, and conductive networks, TCF@FeO@NCLs exhibits excellent reflection loss (RL) of -43.6 dB and effective absorption bandwidth (EBA) of 4.6 GHz (8.2-12.8 GHz) with a loading of 10%. The results demonstrate potentially promising prospects of TCF@FeO@NCLs as new material candidate for microwave absorption.
通过前驱体（PF@FeO@PDA）的一步热解过程，设计并制备了一种具有多层异质结构的新型微波吸收材料（TCF@FeO@NCLs）。PF@FeO@PDA采用受限自缩聚技术、溶剂热法并结合多巴胺（DA）聚合制备而成。所获得的材料具有从内到外依次为嵌入FeO纳米颗粒的管状碳纳米纤维（TCF）、分散的FeO纳米颗粒以及氮掺杂碳层（NCLs）的结构。值得注意的是，管状碳纳米纤维提供主要的介电损耗。FeO纳米颗粒显著提高了低频下的微波吸收能力并提供适当的磁损耗。NCLs提高了导电性并促进了多重极化效应的产生，从而增强了介电损耗。进一步阐明了吸收机制。基于双介电/磁损耗复合材料的协同效应、多层异质结构引入的界面以及导电网络，TCF@FeO@NCLs在负载量为10%时表现出优异的反射损耗（RL）为-43.6 dB，有效吸收带宽（EBA）为4.6 GHz（8.2 - 12.8 GHz）。结果表明TCF@FeO@NCLs作为微波吸收新材料候选具有潜在的广阔前景。
