Abstract: Electromagnetic wave (EMW) absorbers with anti-corrosion property are highly desired to enhance the durability of military targets in harsh condition. Herein, cross-link NiAl-layered double hydroxide (NiAl-LDH) nanosheets on the inner/outer surfaces of carbon microtubes (CMTs) are ingeniously constructed through the combination of atomic layer deposition technique and a hydrothermal method. The obtained NiAl-LDH/CMT composite exhibits excellent EMW absorption and corrosion resistance performance. The large internal cavity of CMT significantly enhances impedance matching. The uniform distribution of NiAl-LDH nanosheets on both the inner and outer surfaces of CMT generates numerous heterogeneous interfaces that induce substantial polarization loss. Consequently, at a filler rate of only 5 wt.%, the NiAl-LDH/CMT composite exhibits a minimum reflection loss of -60.2 dB and a maximum effective absorption bandwidth of 5.9 GHz. In addition, the combined high impermeability of CMT and the effective Cl^--trapping ability of NiAl-LDH endows NiAl-LDH/CMT composite with outstanding corrosion protection property in simulated seawater environment. Furthermore, the PO₄^3- anions are effectively incorporated into the NiAl-LDH interlayer via anion exchange, which can further enhance corrosion protection capacity through surface inactivation from slow-release PO₄^3- anions without reducing their EMW absorption performance. In summary, this work can give guidance for the development of efficient anti-corrosion EMW absorption materials.

Key words: Carbon microtubes, NiAl-LDH, Electromagnetic wave absorption materials, Anti-corrosion property