Tailoring the In‐Plane and Interfacial Polarization in Continuous/Bi‐Gradient MXene/Graphene/Cellulose‐Nanofiber Aerogels Through Gradient Reduction for Absorption‐Dominated Electromagnetic Interference Shielding

Anisotropic aerogels with continuous gradient polarization represent a class of materials that can exhibit high absorption‐dominated electromagnetic interference (EMI) shielding; however, their large‐scale fabrication remains challenging. Here, we report a highly scalable layer‐by‐layer interfacial gelation strategy to obtain a continuous reduction gradient in MXene/partially‐reduced‐graphene(prGO)/cellulose‐nanofiber aerogels, yielding both continuous and stepped‐gradient assembly, in contrast to conventional density‐gradient aerogels. Density functional theory calculations reveal that the strength of the MXene‐prGO interfacial polarization increases continuously along the aerogel depth, due to progressive increase in the graphene reduction level, whereas the in‐plane polarization of prGO follows opposite trend. Such reduction gradient‐induced polarization anisotropy, along with a conductivity gradient, leads to simultaneous increase in EMI absorption and total shielding. The reflection shielding efficiency (SE R ) of the continuous gradient aerogel is as low as 1.57 dB, which increases to 6.75 dB when the gradient is removed, indicating a transition from absorption‐dominated to reflection‐dominated behavior. The resultant stepped‐cum‐continuous gradient aerogels display a total shielding effectiveness (SE T ) of 65.71 dB with a SE R of only 2.71 dB. Seamless gradient aerogels for leak‐tight EMI shielding can be easily achieved by modifying the gelation electrode architecture. Furthermore, these aerogels demonstrate excellent versatility in effective static and dynamic infrared camouflage applications.