The X band (8 GHz–12 GHz) is the electromagnetic wave band emitted by most electronic instruments in our life, which will cause electromagnetic pollution harm to human health. Due to the coexistence of magnetic loss and dielectric loss, the modified Fe₃O₄-carbon-based nanomaterial exhibit strong electromagnetic (EM) wave absorptive capacity. However, there is a problem that the effective absorption bandwidth (EAB, the frequency bandwidth of reflection loss is less than −10 dB) of the X band is narrow. Increasing the EAB value of Fe₃O₄-carbon-based materials is of great significance for reducing electromagnetic pollution. Here, an emulsion-based self-assembly technique and ligand carbonization treatment have been used to construct the Fe₃O₄@C supraparticles for the evaluation of EM performance. The Fe₃O₄@C supraparticles exhibit excellent EM absorption properties, which can achieve full coverage of X band from 6.52 GHz to 12.9 GHz at a sample thickness of 3 mm. Besides, the optimum EAB value of Fe₃O₄@C supraparticles is up to 8.55 GHz from 9 to 18 GHz at a sample thickness of 2.5 mm. The Fe₃O₄@C supraparticles with superlattice structure will have potential development prospects in the application of broadband absorption.

X波段（8 GHz–12 GHz）是我们生活中大多数电子仪器发射的电磁波段，它将对人体健康造成电磁污染危害。由于磁损耗和介电损耗的共存，改性的Fe ₃ O ₄碳基纳米材料表现出较强的电磁波吸收能力。然而，存在X频带的有效吸收带宽（EAB，反射损耗的频率带宽小于-10dB）狭窄的问题。增加Fe ₃ O ₄的EAB值碳基材料对减少电磁污染具有重要意义。在这里，基于乳液的自组装技术和配体碳化处理已用于构建Fe ₃ O ₄ @C超颗粒，用于评估EM性能。Fe ₃ O ₄ @C超颗粒表现出优异的EM吸收性能，在3 mm的样品厚度下可以实现X波段从6.52 GHz到12.9 GHz的完全覆盖。此外，样品厚度为2.5 mm时，Fe ₃ O ₄ @C超颗粒的最佳EAB值从9到18 GHz高达8.55 GHz。铁₃ O ₄具有超晶格结构的@C超粒子在宽带吸收的应用中将具有潜在的发展前景。