Synthesis and microwave absorbing properties of quasione-dimensional mesoporous NiCo2O4 nanostructure

• A quasione-dimensional mesoporous NiCo2O4 nanostructure was synthesized.
• The NiCo2O4 was used as microwave absorber for the first time.
• The NiCo2O4/paraffin composite shows excellent microwave absorbing property.
• The microwave absorbing mechanism was discussed.

Quasione-dimensional NiCo2O4 nanostructure was synthesized by a precipitation-thermal decomposition process. The diameters and special ratios of the NiCo2O4 fibers are 0.2–0.5 μm and 20–50, respectively. The mesoporous structure with a surface area of 54.47 m2 g−1 and average pore-size of 12.5 nm for the NiCo2O4 was obtained. The relative complex permittivity and permeability of paraffin/50 wt.% NiCo2O4 composite were measured in the frequency range of 2–18 GHz, and the microwave absorbing property of the composite was evaluated. An excellent reflection loss (RL) of −35.76 dB at 14.86 GHz with a composite thickness of 1.50 mm and effective bandwidth (RL < −10 dB) of 11.18 GHz were obtained, which is related to the thickness, impedance matching and morphology of the absorber.