Hydrothermal assembly of NiCoAI/Ti3C2Tx MXene composites for tunable microwave absorption

Herein, a new type tunable microwave absorber of NiCoAl/Ti3C2Tx MXene was proposed and synthesized via a simple hydrothermal method. The scanning electron microscopy confirmed that the NiCoAl is of high quality with flower-like structure uniformly bonded on the laminar Ti3C2Tx surface. The dielectric properties of the samples in X-band frequency were studied, and their microwave absorption properties and mechanisms were investigated. Benefit from the synergistic effects of improved interfacial polarization, defect dipole polarization and optimized impedance matching, NiCoAl/Ti3C2T x MXene composites display enhanced microwave absorption. Under a matching thickness of only 1.6 mm, the minimum reflection loss of the absorbers reaches -27.4 dB, and the absorption bandwidth achieves 2.5 GHz. Besides, by adjusting the thickness from 1.4 to 1.8 mm, the effective bandwidth can cover the total X-band. These results demonstrate that the NiCoAl/Ti3C2Tx composites have potentials for both tunable dielectric constant and high-performance microwave absorption.