Microwave shielding properties of chemically synthesized MnO₂ decorated graphene nanoribbons (GNRs) are reported for the first time. The nature of MnO₂ decoration on the GNRs has been investigated using scanning electron microscopy, X-ray diffraction, Raman spectroscopy and high resolution transmission electron microscopy. The electromagnetic interference (EMI) shielding effectiveness of this material was investigated in the microwave region (Ku-band, 12.4–18 GHz). The presence of MnO₂ on GNR enhances the interfacial polarization, multiple scattering, natural resonances and the effective anisotropy energy, which leads to absorption dominated high shielding effectiveness of −57 dB (blocking >99.9999% radiation) by a 3 mm thick sample. Dielectric attributes (ε′ and ε′′) were evaluated to understand the mechanism of the excellent shielding effectiveness. The material will be an excellent choice for radar absorbing applications.

A hybrid three phase system containing MCMBs/MWCNTs/Fe₃O₄in the form of a highly flexible and light weight composite paper is fabricated by simple cost effective strategies and is promising EMI shielding applications.