Construction of lightweight NiCo-LDH/carbon fiber nanocomposites for broad-band microwave absorption

The rapidly increasing usage of electric technology during the last decades has facilitated the fabrication of high-efficiency microwave absorption (MA) materials (MAMs). In this study, hierarchical NiCo layered double hydroxide (LDH)/carbon fiber (CF) nanocomposites were constructed via simple hydrothermal production, and their MA properties were evaluated. Benefiting from interfacial polarization, defect-induced polarization, and multiple reflections induced by the hierarchical sheets, the LDH/CF composites delivered a better MA performance than that by pure CF and LDH. The addition ratio of the LDH also played a vital role in determining the impedance matching and microwave absorption performance. Specifically, the optimized LDH/CF composites demonstrated an exceptional reflection loss (RL) of −62.47 dB with a thickness of 2.22 mm, and an effective absorption bandwidth (EAB) covering 6.4 GHz (11.6–18.0 GHz) at a 20 wt.% filling ratio, which outperformed the reported CF-based microwave absorbers. Owing to this superior MA, the as-prepared LDH/CF composites demonstrated to be significantly promising for advancing the usage of CF-based MAMs.