Ni nanoparticles in situ embedment in 3D ordered macro-/mesoporous carbon framework as efficient microwave absorption and infrared stealth materials

The development of high-performance and multi-modal stealth materials remains a challenge. Herein, nickel nanoparticles embedded in three-dimensionally ordered macro-/mesoporous carbon framework (Ni/OMMC) was fabricated using a facile dual-template approach to achieve efficient microwave absorption and multi-functions. It is found that the carbonization temperature in the preparation process of Ni/OMMC has significant influence on the electromagnetic properties of samples. The optimized microwave absorption performance was achieved by adjusting the calcination temperature to 900 °C. It shows that the minimum reflection loss (RL_min) for Ni/OMMC900 reaches −43.6 dB at 5.0 GHz with a thickness of only 2.0 mm, and effective absorption bandwidth of 5.6 GHz at 1.0 mm with the ultra-low filling ratio of only 3%. Its excellent microwave absorption performance may be attributed to enhanced conductive loss, polarization relaxation and magnetic loss, and impedance matching, which result from magnetic/conductive multi-component synergy and the unique 3D interconnected hierarchically porous structure. Additionally, Ni/OMMC900 exhibits good thermal insulation and infrared stealth functions.