Abstract Molybdenum carbide (β-Mo2C) possesses excellent electrical conductivity, good thermal and chemical stability, and is, therefore, a promising candidate material for electromagnetic (EM) shielding in diverse harsh environments. Herein, for the first time, β-Mo2C based ultra-thin films were prepared through in-situ growth of the carbide on a self-assembled graphene oxide (GO) film. The remaining reduced GO (RGO) layers located in between two adjacent Mo2C nanoparticles not only can work as flexible binder to impart the resultant films excellent flexibility but also enable the formation of heterogeneous nano-interface which is beneficial for the improvement of shielding by absorption. The amounts of β-Mo2C in the resultant films were adjusted through varying the Mo precursor contents. With the introduction of β-Mo2C phase in the resultant film, the shielding effectiveness (SE) increased significantly. At the thickness of ∼25 μm, the highest SE reaches 46.8 dB compared to 21.6 dB of the pristine RGO film. With the increase of the Mo2C content in the resultant materials, the density increased from 0.32 to 1.23 g/cm3. The resultant Mo2C film exhibit an SSE/t (specific SE by thickness) value of as high as 15,971 dB cm2 g−1.

中文翻译：

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通过在氧化石墨烯上原位生长的高柔性和超薄 Mo2C 薄膜用于电磁屏蔽应用

摘要 碳化钼 (β-Mo2C) 具有优异的导电性、良好的热稳定性和化学稳定性，因此是一种在各种恶劣环境中用于电磁 (EM) 屏蔽的有前途的候选材料。在此，首次通过碳化物在自组装氧化石墨烯 (GO) 膜上的原位生长制备了基于 β-Mo2C 的超薄膜。位于两个相邻 Mo2C 纳米粒子之间的剩余还原 GO (RGO) 层不仅可以作为柔性粘合剂赋予所得薄膜优异的柔韧性，而且还可以形成异质纳米界面，这有利于改善吸收屏蔽。通过改变 Mo 前体的含量来调节所得薄膜中 β-Mo2C 的量。随着在所得薄膜中引入 β-Mo2C 相，屏蔽效率（SE）显着增加。在约 25 μm 的厚度下，与原始 RGO 膜的 21.6 dB 相比，最高 SE 达到 46.8 dB。随着所得材料中Mo2C含量的增加，密度从0.32增加到1.23g/cm3。所得的 Mo2C 薄膜表现出高达 15,971 dB cm2 g-1 的 SSE/t（厚度比 SE）值。