Competitively Assembled Aramid‐MXene Janus Aerogel Film Exhibiting Concurrently Robust Shielding and Effective Anti‐Reflection Performance

Abstract The fast progress in electronic devices demands superior anti‐reflective performance of electromagnetic interference shielding materials. However, high‐performance shielding strategies are mainly dependent on reflection effects and this inevitably results in a trade‐off between shielding and anti‐reflective properties during structural designs. Herein, this work proposes a novel gradual heterogeneity design to fundamentally overcome the contradiction. The different steric hindrances in MXene nanosheets and aramid nanoclusters endow the competitively assembled laminal aerogel films with a unique Janus architecture. This Janus structure presents continuous gradient asymmetries and abundant cavities that enable prolonged energy attenuation paths and minimized reflection. Comparing to isotropic counterparts, the gradient design performances a 2174% reduction in reflection coefficient (0.0039) and a 53% increase in shielding efficiency (60.49 dB) in the terahertz band, both of which significantly outperform most state‐of‐the‐art anti‐reflective shielding structures. Moreover, the Janus architecture comprising interconnected arch‐shaped substructures provides the aerogel films with anisotropic EMI and thermal management capabilities, coupled with robust structural and performance stability. This work provides a conceptually novel platform for developing asymmetric architecture for advanced shielding materials.