Controllable adjustment of cavity of core-shelled Co₃O₄@NiCo₂O₄ composites via facile etching and deposition for electromagnetic wave absorption

Area of Science:

• Materials Science
• Nanotechnology
• Electromagnetism

Background:

• Core-shell metal oxides are rarely explored for electromagnetic wave absorption.
• Developing efficient electromagnetic wave absorbers is crucial for modern electronic devices.

Purpose of the Study:

• To fabricate and characterize core-shell Co₃O₄@NiCo₂O₄ composites.
• To investigate the electromagnetic wave absorption properties of these novel composites.
• To correlate microstructure with absorption performance.

Main Methods:

• Fabrication via etching and deposition of cobalt-based metal-organic frameworks.
• Calcination in air to form core-shell structures.
• Morphological analysis and electromagnetic wave absorption testing.

Main Results:

• Successfully synthesized Co₃O₄@NiCo₂O₄ core-shell composites.
• Demonstrated tunable cavity volume through controlled synthesis.
• Achieved a maximum reflection loss (RL) of -34.42 dB.
• Obtained a broad effective absorption bandwidth of 4.88 GHz at 2.6 mm thickness.

Conclusions:

• Multiple interfacial polarizations, including Co₃O₄/Void, Void/NiCo₂O₄, and Co₃O₄/NiCo₂O₄, contribute to high performance.
• Optimized core-shell structures offer excellent electromagnetic wave absorption capabilities.
• Cobalt- and nickel-based metal oxides present a promising avenue for high-performance electromagnetic wave absorbers.