High-performance electromagnetic absorbing Ni/C composites derived from Ni-MOF materials: Effects of organic ligands and pyrolysis temperatures

Abstract

Magnetic carbon-based materials derived from nickel organic framework (Ni-MOF) are considered to be a kind of electromagnetic wave (EMW) absorbing materials with great potential and application value. However, the precise design of Ni-MOF-derived magnetic carbon-based materials remains a huge challenge. In the present work, through the modulation of organic ligand and pyrolysis temperature, Ni/C composites with excellent electromagnetic absorption properties are obtained due to their improved multiple loss and optimized impedance matching. Specifically, the organic ligand and pyrolysis temperature affect the degree of graphitization of the carbon frame and the specific surface area of the Ni/C composites, thus changing the conductivity, magnetic properties and electromagnetic parameters. In particular, the sample Ni/C-2-500 using H₂BPDC as the organic ligand and calcined at 500 °C gives an RL_min of −50.37 dB and an EAB of 6.0 GHz at a packing rate of 30 wt% and a thickness of 2.5 mm, which covers the entire Ku band. In addition, Ni/C-2-500 exhibits good thermal conductivity. Therefore, this study provides an idea for exploring MOF materials and their derivatives with tunable EMW absorbing properties and heat conduction advantages prepared by different organic ligands.