▎ 摘　　要

Molybdenum carbide (beta-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, beta-Mo2C based ultra-thin films were prepared through insitu 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 nanointerface which is beneficial for the improvement of shielding by absorption. The amounts of beta-Mo2C in the resultant films were adjusted through varying the Mo precursor contents. With the introduction of beta-Mo2C phase in the resultant film, the shielding effectiveness (SE) increased significantly. At the thickness of similar to 25 mu m, 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/cm(3). The resultant Mo2C film exhibit an SSE/t (specific SE by thickness) value of as high as 15,971 dB cm(2) g(-1). (C) 2020 Elsevier Ltd. All rights reserved.