Synergistic self-assembly of MXene monolayer dispersions doped with NiFe2O4 nanoparticles for high-performance microwave absorbers

To address the growing issue of electromagnetic radiation pollution, developing efficient electromagnetic wave-absorbing materials is both urgent and challenging. Transition metal carbides/nitrides (MXenes) are excellent conductors of electricity and possess various surface groups and imperfections, making them valuable for studying their microwave absorption capabilities. However, the complex preparation process and limited loss mechanisms of MXenes do not meet the essential requirements for wave-absorbing materials. A mild co-solvent thermal method creates a novel multi-heterostructure wave-absorbing material made of 2D monolayer MXene nanosheets and NiFe₂O₄ nanoparticles. The MXene@NiFe₂O₄ heterostructured material demonstrates effective impedance matching, electromagnetic coupling, polarization loss due to heterogeneous interfaces and defects, along with multiple reflections and scattering, resulting in excellent electromagnetic wave absorption performance. Notably, the final electromagnetic wave absorption performance of the MXene@NiFe₂O₄ hybridized materials is closely linked to their electromagnetic parameters, which can be adjusted by varying the composition ratio of NiFe₂O₄ nanoparticles. The findings suggest that by using a molar ratio of 1:0.5 of Fe in NiFe₂O₄ nanoparticles and a loading of 30 wt% of MNF, the MNF hybrids achieve a minimal reflection loss (RL_min) of − 43.9 dB at 12.39 GHz (99.994% absorption of the electromagnetic wave); the effective absorption bandwidth (EAB, RL <  − 10 dB) is 5.78 GHz, encompassing the whole X-band. This endeavor can provide significant insights into the potential applications of few-layer MXene-based composites in highly effective electromagnetic wave absorption.