Ordered TiO₂ transition layer for balanced impedance-matching enabling TiO₂/C/RGO porous foam low filler loading and enhanced electromagnetic wave absorption performance

The incoordination of attenuation capability and impedance matching due to over conductivity and single loss mechanisms severely limit the application of reduced graphene oxide (RGO) in electromagnetic wave (EMW) absorption. At this study, TiO₂/C/RGO nanocomposites are successfully fabricated by introducing monolayer Ti₃C₂T_x (m-Ti₃C₂T_x) into RGO and building a porous foam structure. The ordered TiO₂/C layer derived from m-Ti₃C₂T_x acts as a low-dielectric transition layer, effectively optimizing the impedance matching, while the large heterogeneous interfaces composed with RGO provide more relaxation processes. The foam structure allows EMW to easily enter the interior, where scattering and refraction occur to lengthen the loss path. With only 5 wt% filler loading and a 2 mm coating thickness, the as-prepared sample has a −46.48 dB (15.92 GHz) minimum reflection loss (RL_min), as well as an ultra-wide effective absorption bandwidth (EAB) of 5.76 GHz. In comparison, with the same filling loading, RGO barely achieves effective absorption (RL < −10 dB), while m-Ti₃C₂T_x has no EMW absorption properties at all. As a result, this work explored a practical approach for light-weight and high-performance in EMW absorption.