Initiating Binary Metal Oxides Microcubes Electrsomagnetic Wave Absorber Toward Ultrabroad Absorption Bandwidth...

Area of Science:

• Materials Science
• Nanotechnology
• Electromagnetics

Background:

• Cobalt nickel bimetallic oxides (NiCo2O4) show promise for electromagnetic wave (EMW) absorption due to controllable morphology and high performance.
• Broadening the absorption bandwidth of NiCo2O4-based materials remains a significant challenge.

Purpose of the Study:

• To fabricate unique NiCo2O4@C core-shell microcubes with hollow structures for improved EMW absorption.
• To optimize the material's properties by controlling oxygen vacancies and morphology through calcination temperature.

Main Methods:

• A facile sacrificial template strategy was employed to synthesize NiCo2O4@C core-shell microcubes.
• Calcination temperature was adjusted to optimize oxygen vacancy concentration and morphology of the 3D framework.
• Electromagnetic wave absorption properties were evaluated.

Main Results:

• The 3D hollow core-shell structure facilitated multiple reflections and interfacial polarization losses.
• Optimized oxygen vacancies induced dipole polarizations, enhancing EM wave attenuation.
• The optimized NiCo2O4@C hollow microcubes achieved a minimum RL of -84.45 dB at 8.4 GHz and an ultrabroad effective absorption bandwidth (EAB) of 12.48 GHz (5.52-18 GHz).

Conclusions:

• The developed NiCo2O4@C hollow microcubes demonstrate superior EMW absorption capability, particularly in achieving broad absorption bandwidth.
• This work provides a pathway for synthesizing high-performance cobalt nickel bimetallic oxides for advanced EMW absorber applications.