3D Honeycomb Fe/MXene Derived from Prussian Blue Microcubes with a Tunable Structure for Efficient Low-Frequency and Flexible Electromagnetic Absorbers

The unique layered structure and high conductivity of MXene materials make them highly promising for microwave absorption. However, the finite loss mechanism and severe agglomeration present challenging obstacles for ideal microwave absorbers, which could be effectively improved by constructing a three-dimensional (3D) porous structure. This study reports a 3D honeycomb MXene using a straightforward template method. The 3D MXene framework offers ample cavities to anchor the Prussian blue microcubes and their derivatives including Fe microboxes and Fe clusters by a simple annealing process. Based on the superiority of the 3D honeycomb architecture and magnetic-dielectric synergistic effects, the Fe/MXene absorbers demonstrate outstanding microwave absorption capabilities with the optimum reflection loss value of -40.3 dB at 2.00 mm in the low-frequency range from 4.2 to 5.6 GHz. The absorber also manifests superior radar wave attenuation by finite element analysis and exhibits great potential to be a flexible and thermal insulation material in a wide range of temperatures. This work proposes a useful reference for the design of 3D MXene-based porous architectures, and the synergistic magnetic-dielectric strategy further expands the potential of MXene-based absorbers, enabling them to be used as flexible and highly efficient microwave absorbers.

Automated summary

This study successfully prepared a 3D honeycomb MXene using a template method and achieved composite with Prussian blue microcubes and Fe clusters. The 3D MXene absorbers demonstrated outstanding microwave absorption capabilities and radar wave attenuation performance based on the superiority of the 3D honeycomb architecture and magnetic-dielectric synergistic effects. They also showed great potential as flexible and thermal insulation materials.