Monolayer Interfacial Assembly toward Two-Dimensional Mesoporous Heterostructure for Boosting Wave Absorption

Microwave absorption materials play a key role in various fields, including military stealth, human safety protection, and so on. Construction of 2D mesoporous heterostructures is an attractive approach to enhance wave-absorbing ability, while it is still a great challenge. Herein, 2D mesoporous carbon-MXene-carbon heterostructures (MCMCH) with channels parallel to surface are successfully prepared via a monolayer interfacial assembly strategy. Through the precise adjustment and polymerization, cylindrical micelles orderly monolayered assemble on both surfaces of 2D MXene nanosheets, resulting in 2D switch-like polydopamine-MXene-polydopamine nanosheets, and 2D MCMCH are finally generated by further calcination. Due to the excellent dielectric polarization relaxation and conductive loss, MCMCH achieves the strongest reflection loss of −54.2 dB at a thickness of only 1.5 mm. The presence of mesochannels not only introduces air with a low permittivity for optimal impedance matching, but also further extends the attenuation path of the incident electromagnetic wave. The maximum radar cross-section reduction of 26.9 dB m² is achieved for the MCMCH compared to the perfect electric conductor. This work provides a reference for surface engineering based on 2D mesoporous heterostructures to enhance the microwave absorption performance.