Hollow MOF-derived CoNi/C composites as effective electromagnetic absorbers in the X-band and Ku-band

Abstract

Metal–organic framework (MOF) derivatives have received extensive attention in the field of microwave absorption due to their unique advantages and various properties. In this work, cubic hollow CoNi/C composites were prepared by in situ pyrolysis of ZIF-67. The CoNi nanoparticles are uniformly distributed in the N-doped porous carbon matrix by controlling the pyrolysis process. The composites exhibited outstanding electromagnetic wave absorption performance with a unique hollow structure, high porosity, double loss mechanism and abundant functional groups. When the matching thickness is 3.9 mm, the optimal reflection loss (RL) value can be as low as −61.8 dB and the effective absorption bandwidth can reach 10.2 GHz (from 7.8 to 18 GHz) containing the entire X-band and Ku-band. The simple synthesis method and excellent microwave absorption properties prove that CoNi/C carbon-based composites derived from MOFs can be potential ideal microwave absorbing materials.