ZIF-67 derived porous core-shell nanocomposites for high-efficiency electromagnetic absorption

N-doped porous core-shell nanocomposite is considered to be a competent candidate for the absorbing of electromagnetic wave (EMW). In this work, polydopamine (PDA) wrapped ZIF-67 (Z@P) precursors with the core-shell structure were obtained through ZIF-67 triggered dopamine self-polymerization. After high-temperature pyrolysis treatment, the N-doped graphitized carbon layers wrapped cobalt (Co@CNs) absorber with porous structure was obtained, which exhibited high efficiency and adjustable EMW absorbing properties. The minimum reflection loss (RLmin) of Co@CN-60 approached −59.08 dB at 17.7 GHz with a thickness of 1.7 mm. The effective absorption bandwidth (EAB) reached 5.8 GHz with a corresponding thickness of 2.3 mm. Besides, the RLmin of Co@CN-90 reaches −44.07 dB at 14.5 GHz (thickness 2.0 mm), and the EAB is 5.9 GHz. Therefore, the porous core-shell Co@CNs nanocomposite is expected to be a promising EMW absorption material.