Controllable coating NiAl-layered double hydroxides on carbon nanofibers as anticorrosive microwave absorbers

For harsh real-world service settings, it is essential to build corrosion-resistant, diverse, and effective microwave absorbers. Herein, we successfully prepared a 3D NiAl-layered double hydroxide/carbon nanofibers (NiAl-LDH/CNFs) composite material as an anticorrosive microwave absorber assisted by an atomic layer deposition (ALD) method. The size, coating thickness, and content of NiAl-LDH can be readily adjusted by changing the ALD cycling numbers. The optimized NiAl-LDH/CNFs demonstrates prominent microwave absorbing properties including the strongest reflection loss of –55.65 dB and the widest effective absorption bandwidth of 4.80 GHz with only 15 wt% loading. The reasons for performance improvement are the cooperative effect of interfacial polarization loss, conduction loss, and three-dimensional porous structure. Moreover, due to the synergistic effects between the excellent impermeability of CNFs and the trapping ability of NiAl-LDH for chloride ions, NiAl-LDH/CNFs exhibits strong corrosion resistances under acidic, neutral, and alkaline conditions. NiAl-LDH/CNFs should be a potential candidate to simultaneously use for microwave absorption and corrosion resistance, and this work provides a certain guiding significance for designing microwave absorbers that satisfy the corrosion resistance.