Three-dimensional lightweight melamine foams modified by MXene sheets and CoNi alloys towards multifunctional microwave absorption

Taking the increasing issue of electromagnetic waves (EMW) pollution and the necessity for applications in extreme environments, there is a pressing requirement to create multifunctional microwave absorption materials (MAMs) to meet the current challenges. In this work, we achieved the successful combination of MXene sheets and MOFs derived CoNi@C magnetic alloys onto the three-dimensional (3D) melamine foam (MF) skeleton using vacuum impregnation and electrostatic self-assembly techniques. The obtained MF@MXene/CoNi@C composite foams achieved outstanding MA performance, with an optimal reflection loss (RL) value of -24.1 dB and a maximum effective absorption bandwidth (EAB) of 6.88 GHz at a thickness of 1.68 mm, effectively covering the whole Ku band. The superior MA performance is ascribed to the composite foams' multi-component architecture, distinctive 3D porous structure, and the synergistic impact of multiple loss mechanisms. Moreover, the MF@MXene/CoNi@C composite foams demonstrate exceptional photothermal conversion, thermal insulation, and infrared stealth capabilities, effectively coping with the demands of applications in extreme environments. This work serves as a valuable resource and source of inspiration for the development of lightweight-broadband, multifunctional efficient MAMs.