Multilayer Ultrathin MXene@AgNW@MoS2 Composite Film for High- Efficiency Electromagnetic Shielding

Structure and material composition is crucial in realizing high electromagnetic interference (EMI) shielding effectiveness (SE). Herein, an ultrathin MXene@AgNW@MoS2 (MAM) composite film that resembles the structure of a pork belly and exhibits superior EMI shielding performance was fabricated via the vacuum-assisted suction filtration process and atomic layer deposition (ALD). The staggered AgNWs form skeletons and intersperse in MXene sheets to build a doped layer with three-dimensional network structures, which improves the electrical conductivity of the film. Based on the optimal dispersion concentration of Ag in doped and single layers, the MXene/AgNW doped layer and AgNW single layer are alternately vacuum assisted-filtered to obtain laminated structures with multiple heterogeneous interfaces. These interfaces generate interface polarization and increase multiple reflection and scattering, resulting in the increased electromagnetic (EM) wave losses. On the other hand, MoS2 outer nanolayers fabricated precisely by ALD effectively increases the absorption proportion of electromagnetic waves, reduces the secondary reflection, and improves the stability of EMI shielding properties. Ultimately, an ultrathin MAM film (a thickness of 0.03 mm) with five alternating internal layers and MoS2 outer layers exhibits an excellent EMI SE of 86.3 dB in the X-band.

Automated summary

An ultrathin MXene@AgNW@MoS2 (MAM) composite film with a structure resembling that of a pork belly was fabricated through vacuum-assisted suction filtration process and atomic layer deposition (ALD), resulting in superior EMI shielding performance. The film consists of staggered AgNWs forming skeletons interspersed in MXene sheets, creating a doped layer with three-dimensional network structures that enhances the film's electrical conductivity. Additionally, MoS2 outer nanolayers fabricated precisely by ALD increase the absorption proportion of electromagnetic waves, reduce secondary reflection, and improve the stability of EMI shielding properties. The ultrathin MAM film with five alternating internal layers and MoS2 outer layers exhibits excellent EMI shielding effectiveness of 86.3 dB in the X-band.