Yuan Xiaoyan, Wang Ruiqin, Huang Wenrui, Kong Luo, Guo Shouwu, Cheng Laifei
School of Materials Science and Engineering, Shaanxi Key Laboratory of Green Preparation and Functionalization for Inorganic Materials, Shaanxi University of Science and Technology, Xi'an, 710021, China.
Science and Technology on Thermostructural Composite Materials Laboratory, Northwestern Polytechnical University, Xi'an 710072, China.
ACS Appl Mater Interfaces. 2020 Mar 18;12(11):13208-13216. doi: 10.1021/acsami.9b23310. Epub 2020 Mar 4.
To enhance microwave loss abilities, constructing composites with one-dimensional (1D) structure is an excellent scheme. In this work, a high-efficiency microwave absorber of MnO nanograins decorated vanadium nitride/carbon nanofibers (MnO-VN/C NFs) was successfully prepared for the first time via co-electrospinning technology and subsequent nitriding treatment. Studying in detail the specific relationship between nitriding time and the morphology of the as-prepared NFs, the precipitations of MnO nanoparticles with tailored structures were attached on the surface of VN/C NFs to optimize their electromagnetic parameters. When the nitriding time was 2.0 h at 600 °C, the MnO-VN/C NFs displayed good microwave absorption performances: the minimum reflection loss (RL) value was -63.2 dB at 8.8 GHz, and the bandwidth of RL < -10 dB was up to 6.4 GHz from 11.6 to 18 GHz at the thickness of 2.8 mm. Meanwhile, the absorption bandwidth (RL< -10 dB) could cover the whole X and Ku band by adjusting the thickness, respectively. The outstanding performances could be attributed to the good impedance matching and various loss pathways including conductive loss and interfacial and dipole polarizations. In these regards, MnO-VN/C NFs are likely to be utilized as a high-efficiency microwave absorber. And the strategy in this work can provide great help to design other 1D structural microwave absorbers with a broader absorbing band.
为了提高微波损耗能力，构建具有一维（1D）结构的复合材料是一种出色的方案。在这项工作中，首次通过共电纺丝技术和后续氮化处理成功制备了MnO纳米颗粒修饰的氮化钒/碳纳米纤维（MnO-VN/C NFs）高效微波吸收剂。详细研究氮化时间与所制备NFs形貌之间的具体关系，具有定制结构的MnO纳米颗粒沉淀附着在VN/C NFs表面以优化其电磁参数。当在600℃下氮化时间为2.0 h时，MnO-VN/C NFs表现出良好的微波吸收性能：在8.8 GHz时最小反射损耗（RL）值为-63.2 dB，在厚度为2.8 mm时，RL < -10 dB的带宽从11.6到18 GHz高达6.4 GHz。同时，通过分别调整厚度，吸收带宽（RL < -10 dB）可以覆盖整个X和Ku波段。这些优异的性能可归因于良好的阻抗匹配以及包括传导损耗、界面极化和偶极极化在内的各种损耗途径。在这些方面，MnO-VN/C NFs有望用作高效微波吸收剂。并且这项工作中的策略可以为设计具有更宽吸收带的其他一维结构微波吸收剂提供很大帮助。
