Facile synthesis 3D porous MXene Ti3C2Tx@RGO composite aerogel with excellent dielectric loss and electromagnetic wave absorption

3D porous materials with ultralight density, thin thickness, strong, and broadband absorption are attracting attention as promising candidates as novel microwave absorbents. Herein, a unique 3D porous MXene Ti3C2Tx@RGO hybrid aerogel was fabricated via a hydrothermal method and freeze-drying treatment. The network-like 3D heterostructure, which combines 2D MXene and RGO sheets, can reduce stacked nanosheets, and provides an efficient interface structure, which benefits electromagnetic (EM) energy attenuation. More significantly, their microwave absorption properties have been quite efficiently enhanced over pristine 2D Ti3C2Tx nanosheets. Only with 15 wt% filler loading, the minimum reflection loss of the Ti3C2Tx@RGO composite aerogel reaches −31.2 dB at 8.2 GHz, and the effective frequency bandwidth (below −10 dB) achieves up to 5.4 GHz at a thickness of only 2.05 mm. The illustrated EM wave response mechanism indicates that the highly conductive network, interface polarization, dipole polarization, and multiple scattering contribute importantly to its EM wave absorption. Therefore, the synthesized MXene Ti3C2Tx@RGO composite aerogel offers a sufficient foundation for utilization as a perfect absorbent and in the design of other lightweight microwave absorbers.