Carbon nanotube modified hierarchical NiCo/porous nanocomposites with enhanced electromagnetic wave absorption

Abstract

The rational modulating of the microstructure in magnetic carbon-based composites is crucial to optimize the electromagnetic wave (EMW) absorption performance. It is challenging for EMW absorbers to simultaneously achieve optimal minimum reflection loss (RLmin) and a broadband effective absorption bandwidth (EAB). In this paper, carbon nanotubes (CNTs)-modified NiCo/CNTs nanosheets were effectively prepared as a new EMW absorption material utilizing NiCo-containing metal-organic framework (MOF) as a sacrificial precursor. As expected, NiCo/CNTs-650 demonstrated both a broadband EAB of 7.04 GHz and the RLmin of − 58.14 dB at 15.9 GHz with a thickness of 2.0 mm. Furthermore, NiCo/CNTs-650 is capable of achieving 30.2 dB m2 RSC (radar cross section) reduction under an incident angle of 7° via CST, while NiCo/CNTs-70015 % achieved a reduction of 39.47 dB m2 at 0 °. These performances outperformed that other CNTs-decorated MOF-derived hierarchical composites previously described. NiCo/CNTs-650 combines the synergistic effects of magnetic loss provided by zero-dimensional (0D) NiCo alloy, dielectric attenuation realized by one-dimensional (1D) CNTs, and optimized impedance matching through two-dimensional (2D) nanosheets with abundant hierarchical interfaces. These studies provide a specialized route for the manufacture of mixed-dimensional hierarchical EMW absorbents with high performance.