Highly flexible and ultrathin Mo2C film via in-situ growth on graphene oxide for electromagnetic shielding application

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.