Abstract To improve the microwave absorption and antioxidation abilities of Cu nanowires (NWs) as microwave devices, we synthesized Cu/Fe/C and hollow Cu/Fe3O4/C core-shell nanowires (CSNWs) chemically converted from Cu2O/PPy CSNWs via an in-situ carbothermic reduction-CVD process. Changing temperature (Tc) and Fe(CO)5 vol (V) could handily adjust the surface component and structure of the products. Controlling N2 purity could selectively synthesize hollow Cu/Fe3O4/C CSNWs and solid Cu/Fe/C CSNWs with a strawberry-shaped surface based on the surface diffusion mechanism. The Cu/Fe/C CSNWs and hollow Cu/Fe3O4/C CSNWs possessed high soft magnetic and microwave absorbing properties. Considering the combination of high electromagnetic parameters, double dielectric relaxation and magnetic resonance, intense absorption, and excellent impedance matching, Cu/Fe/C CSNWs formed at Tc = 600 °C and V = 4 mL were superior absorbents that were characterized by high absorption, wide bandwidth, and light weight. The maximal reflection loss (RL) was −43.09 dB at 13.07 GHz with a 1.8 mm matching thickness, and RL values below −20 dB could be gained over 3.3–4.5 GHz and 5.11–15.9 GHz. This work has provided a general method for modulating the surface/interface and structure of carbon-based magnetic composites for lightweight and broad bandwidth microwave absorbing materials.

中文翻译：

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Cu2O/PPy核壳纳米线（CSNWs）的化学转化：具有优异微波吸收能力的高质量Cu/Fe/C和Cu/Fe3O4/C CSNWs的表面/界面调整方法

摘要 为了提高作为微波器件的 Cu 纳米线 (NWs) 的微波吸收和抗氧化能力，我们合成了 Cu/Fe/C 和空心 Cu/Fe3O4/C 核壳纳米线 (CSNWs)，由 Cu2O/PPy CSNWs 通过 in -原位碳热还原-CVD工艺。改变温度 (Tc) 和 Fe(CO)5 vol (V) 可以方便地调整产品的表面成分和结构。基于表面扩散机制，控制 N2 纯度可以选择性地合成空心 Cu/Fe3O4/C CSNW 和具有草莓形表面的实心 Cu/Fe/C CSNW。Cu/Fe/C CSNWs和空心Cu/Fe3O4/C CSNWs具有高软磁和微波吸收性能。考虑到高电磁参数、双重介电弛豫和磁共振、强吸收和优异的阻抗匹配的组合，在 Tc = 600 °C 和 V = 4 mL 下形成的 Cu/Fe/C CSNWs 是优良的吸收剂，其特点是高吸收、宽带宽和重量轻。最大反射损耗 (RL) 在 13.07 GHz 时为 -43.09 dB，匹配厚度为 1.8 mm，在 3.3-4.5 GHz 和 5.11-15.9 GHz 范围内可以获得低于 -20 dB 的 RL 值。这项工作为调节碳基磁性复合材料的表面/界面和结构提供了一种通用的方法，用于轻质和宽带宽微波吸收材料。