Enhanced electromagnetic wave response of nickel nanoparticles encapsulated in nanoporous carbon

Nickel nanoparticles embedded nanoporous carbon (NPC/Ni) was fabricated via thermal treatment of metal organic framework precursors. Nickel particles were uniformly dispersed in the nanoporous carbon network under certain sintering temperature. Meanwhile, the obtained magnetic metal Ni could improve the electrical conductivity of carbon due to its graphitization catalysis on amorphous carbon. The obtained multiple interfaces, porous structures as well as tunable electrical conduction are all beneficial to the enhanced microwave absorption. The sample prepared at 700 °C exhibits nice microwave absorption capacity with the maximum reflection loss (RL) value of −39.4 dB and effective bandwidth of 4.2 GHz. In addition, the prepared sample exhibit huge potential as light absorber. When sample loading content decreases from 30 wt% to 25 wt%, its maximum RL value reaches −39.4 dB with an effective bandwidth of 4.2 GHz. This work not only demonstrates that the NPC/Ni composites are excellent absorbers with wide bandwidth, strong absorption, thin thickness and light weight, but also initiates a new pathway for artificially designed magnetic metal/dielectrics composites nanostructures with objective functionalities.