Gradient structured MoS2@MXene/MXene/aramid nanofiber composite film with excellent electromagnetic interference shielding performance

Developing high-performance electromagnetic interference (EMI) shielding materials with robust microwave attenuation capabilities and structural stability remains a formidable challenge to enhance their practical adaptability in everyday scenarios. In this study, we have successfully fabricated a gradient structured MXenebased composite film tailored for high-performance EMI shielding. Initially, a hybrid MoS2@MXene material featuring heterointerfaces is synthesized, which exhibits exceptional electromagnetic wave (EMW) absorption capabilities. Subsequently, a gradient structured multi-layer film is engineered using a layer-by-layer casting approach, gradually increasing the MXene content in the MoS2@MXene/MXene/aramid nanofiber composite. This composite film is purposefully designed to employ an "absorb-reflect-reabsorb" EMI shielding mechanism, resulting in reduced reflection power. The resultant composite film achieves an impressive EMI SE of 50.9 dB, coupled with remarkable structural stability persisting through 500 folding cycles. This study presents a viable and potent strategy for developing flexible, absorption-dominant EMI shielding materials.