LAUSR

Abstract Highly conductive materials, with minimal thickness and capable to afford electromagnetic interference (EMI) shielding, are highly advantageous, particularly if they are able to be easily processed into thin films. Here, we demonstrate the potential of a sandwich-like structure of a two-dimensional Ti3C2Tx MXene/Graphene nanoplatelets (GNPs) composites for EMI shielding in the extreme high frequency (EHF) M-band, ranging from 60 to 80 GHz. First, we investigated systematically the microstructural and electrical transport properties of these composites with respect to the GNP contents. After graphene integration, the composite-surface roughness has been found to decrease, while both electrical conductivity and Hall carrier mobility demonstrated a clear trend to increase, reaching the values of ∼ 105 S/cm and 55 cm2/Vs, respectively, for only 2.5 wt. % of graphene content, reporting thereby one of the most electrically conductive MXene based composite to date. Furthermore, a 1.75 μm-thick Ti3C2Tx MXene/GNP film was found to exhibit an EM absorbance of about 64 decibels, which is one of the highest values, normalized to the thickness, among tested materials so far. This remarkable performance could be associated to three key factors, namely the superior transport properties of the composite films, the dominant absorption mechanism, and the multiple internal reflections from Ti3C2Tx and graphene multilayers configuration. These reported results would lead to unprecedented applications in the fields of space, aeronautics, radars, air travels and mobile phones.