Optimization of porous FeNi3/N-GN composites with superior microwave absorption performance
Optimization of porous FeNi3/N-GN composites with superior microwave absorption performance
复制标题
具有优异微波吸收性能的多孔 FeNi3/N-GN 复合材料的优化
DOI：
10.1016/j.cej.2018.04.006
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发表时间：
2018-08-01
影响因子：
15.1
通讯作者：
Zheng, Xinliang
中科院分区：
文献类型：
--
作者：
Feng, Juan;Zong, Yan;Zheng, Xinliang
了解杂化材料中结构单元的微观结构、相互作用和协同效应，可以为微波吸收剂的合理构建和应用提供巨大的潜力。在此，FeNi 3纳米晶修饰在N掺杂的石墨烯纳米片上制备作为高效协同微波吸收剂。通过改变N掺杂石墨烯的量，可以控制FeNi 3纳米晶的形貌在中空/多孔结构和团簇之间。结合磁性FeNi 3纳米晶和介电N掺杂石墨烯的协同效应，杂化物表现出比FeNi 3纳米晶和N掺杂石墨烯大幅度提高的微波吸收能力。最佳混合体的最大反射值为-57.2dB，超薄厚度仅为1.45mm，相应的有效带宽大于3.4GHz（14.6-18 GHz）。复合材料吸波性能的显著增强主要源于有效的阻抗匹配条件、良好的衰减能力、FeNi 3纳米晶磁损耗与N掺杂石墨烯介电损耗的良好互补性以及多重界面极化。这些结果表明，FeNi 3/N掺杂石墨烯杂化材料具有强吸收、宽带宽、重量轻和厚度小的特点，是商业化微波吸收剂的有希望的候选者。
Understanding the microstructure, interaction and synergistic effect of building blocks in hybrid material can offer immense potential for the rational construction and applications of microwave absorbers. Herein, FeNi3 nanocrystals decorated on N-doped graphene nanosheets were fabricated as high-efficiency synergistic microwave absorbers. The morphologies of FeNi3 nanocrystals can be controlled between hollow/porous structure and clusters by changing the amount of N-doped graphene. Combined synergistic effect of magnetic FeNi3 nanocrystals and dielectric N-doped graphene, the hybrids exhibit greatly improved microwave absorption capacities compared to FeNi3 nanocrystals and N-doped graphene. The optimal hybrids show a maximum reflection value of -57.2 dB with an ultrathin thickness of only 1.45 mm, and the corresponding effective bandwidth is larger than 3.4 GHz (14.6-18 GHz). The remarkably enhanced microwave absorption properties of the hybrids are mainly originated from the effective impedance matching condition, improved attenuation capacity, well complementarities between magnetic loss from FeNi3 nanocrystals and dielectric loss from N-doped graphene, and multiple interfacial polarizations. These results suggest that the FeNi3/N-doped graphene hybrids with strong absorption, broad bandwidth, light weight and ultrathin thickness are promising candidate towards the commercialization of microwave absorbers.