Enhanced electromagnetic absorbing performance of MOF-derived Ni/NiO/Cu@C composites

Metal-organic frameworks (MOFs) appear as promising candidates for microwave absorbing materials with a low density as well as tunable electromagnetic parameters. In this study, a facile strategy to fabricate microwave absorbing materials has been demonstrated by introducing metallic Ni nanoparticles into carbon matrix which takes advantage of extremely porous structure. The magnetic Ni composition in the final products can be controlled, which offers an effective way to tune electromagnetic properties. Interfacial polarization is considered to be one of the most important attenuation mechanisms, which can be changed by increasing the interface area and electrical conductivity. When the filler loading of Ni/NiO/Cu@C composite in paraffin matrix is only 10 wt%, a minimum reflection loss of -38.1 dB is achieved at a layer thickness of 3.2 mm. The low density of the filler loading can be guaranteed by enhancing the conduction loss and impedance matching.