Hollow Ni/C microspheres derived from Ni-metal organic framework for electromagnetic wave absorption

Hollow nickel/carbon (Ni/C) microsphere was synthesized by in situ pyrolysis of the Ni-based trimellitic acid framework (Ni-MOF) at argon atmosphere. The morphology of Ni-MOF precursor can be easily controlled by adjusting the volume ratio of DMF and H2O in solvothermal process. When the volume ratio of DMF: H2O is 2: 1, hollow Ni-MOF microspheres can be obtained and the corresponding Ni/C composite exhibits extremely strong electromagnetic wave absorption. The maximum reflection loss is up to -57.25 dB with the matching thickness of only 1.8 mm, while the corresponding effective absorption bandwidth (reflection loss below-10 dB) achieves 5.1 GHz. The excellent electromagnetic wave absorbing capabilities is related to the hollow structure and the synergistic effect between carbon and nickel nanoparticles. This work confirms that the as-prepared Ni/C composite with superior electromagnetic wave absorption properties is a promising candidate for lightweight electromagnetic wave absorbing materials.