Anisotropic electromagnetic absorption of the aligned Ti3C2Tx MXene/RGO nanocomposite foam

Transition metal carbides/nitrides (MXenes) with superb electrical properties have excellent applications for electromagnetic wave absorption (EMA). Whereas, the three-dimensional (3D) MXene's fabrication assemblies with anisotropic EMA performance are still a challenge as MXene nanosheets have weak gelation capabilities. In this study, graphene oxide was introduced to assist in fabricating the 3D MXene/RGO porous foam through the method of unidirectional freeze casting followed by hydrazine hydrate chemical reduction. Combined with the excellent electrical properties of MXene and RGO, the resultant lightweight (similar to 6 mg/cm(3)) MXene/RGO composite foam (MGF) with a free-standing configuration exhibits anisotropic microwave absorption performance. At the sample thickness of 5 mm, MGF-1/2 shows -26.79 dB minimum reflection loss at 4.39 GHz along the perpendicular direction that relates to the unidirectional freeze casting direction. While along the parallel direction, materials with 3 mm thickness reach the maximum effective bandwidth of 8.34 GHz. The lightweight MXene/RGO nanocomposite foam with anisotropic performance may significantly extend the feasibility of MXenes in EMA.

Automated summary

This study introduces graphene oxide to assist in fabricating three-dimensional MXene/RGO porous foam with anisotropic electromagnetic absorption performance. At a sample thickness of 5 mm, the minimum reflection loss in the perpendicular direction reaches -26.79 dB, while materials with a thickness of 3 mm in the parallel direction achieve a maximum effective bandwidth of 8.34 GHz. This lightweight MXene/RGO nanocomposite foam with anisotropic performance could significantly expand the applicability of MXenes in electromagnetic wave absorption.