Abstract: Different carbon-based nanocomposites have been elaborately designed as advanced microwave absorbers (MAs) owing to the unique structures and excellent chemical and physical properties of carbon materials. In this work, a novel class of magnetic CoFe/C@bamboo-like carbon nanotubes (BLCNTs) core@shell nanocomposites (CSNCs) were efficiently produced through a simple catalytic decomposition of dicyandiamide (DCD) using CoFe-nitrilotriacetic acid chelate as catalyst precursor. By controlling the amount of DCD, CoFe/C@BLCNTs CSNCs with different BLCNTs contents could be selectively synthesized. The generation of BLCNTs greatly improved the electromagnetic (EM) and EM wave absorption properties (EMWAPs) of CoFe/C. Furthermore, the EM and EMWAPs could be further improved by controlling the pyrolysis temperature. Especially, the optimized CoFe/C@BLCNTs CSNCs exhibited a minimum reflection loss of -21.96 dB at 1.91 mm and an effective absorption bandwidth of 6.80 GHz at 2.27 mm. The acquired results demonstrated that the designed CoFe/C@BLCNTs CSNCs exhibited low density, broadband absorption bandwidth, strong EM attenuation ability, and excellent corrosion resistance, which originated from the excellent magnetic-dielectric synergic, interfacial effect, and generation of BLCNTs. Therefore, a facile metal chelate-derived and catalytical strategy was proposed to successfully produce a novel class of CoFe/C@BLCNTs CSNCs, which could act as lightweight, broadband advanced MAs.

Key words: Magnetic core@shell nanocomposites, CoFe/C@bamboo-like carbon nanotubes, Broadband, Corrosion resistance, Microwave absorption