Interface-Synergy-Driven Core-Shell Engineering of Hierarchical Hollow Structures for Enhanced Multifunctional...

Area of Science:

• Materials Science
• Nanotechnology
• Electromagnetics

Background:

• Next-generation communication technologies require materials with effective low-frequency electromagnetic wave absorption and environmental durability.
• Single-component silicon carbide (SiC) nanospheres exhibit limitations in low-frequency absorption due to poor polarization, lack of magnetic loss, and impedance mismatch.
• There is a need for multifunctional materials that overcome these limitations and provide robust performance in demanding environments.

Purpose of the Study:

• To design and synthesize a novel core-shell material combining silicon carbide (SiC) nanospheres with a bimetallic metal-organic framework (MOF)-derived carbon matrix.
• To investigate the electromagnetic wave absorption properties, particularly at low frequencies, and the environmental durability of the developed composite.
• To establish a new design paradigm for multifunctional absorbers suitable for advanced communication systems.

Main Methods:

• Fabrication of a core-shell structure using hollow SiC nanospheres coated with a bimetallic CoNi-MOF-derived carbon matrix.
• Characterization of the material's morphology, composition, and structure.
• Evaluation of electromagnetic wave absorption performance, including reflection loss and effective absorption bandwidth, especially in the low-frequency range relevant to 5G.
• Assessment of anticorrosion performance through electrochemical measurements, including corrosion potential and current density.

Main Results:

• The SiC@CoNi/C-3 composite achieved a minimum reflection loss of -64.39 dB at 5.44 GHz and a maximum effective absorption bandwidth of 5.20 GHz.
• A significant low-frequency absorption bandwidth of 1.76 GHz (4.80-6.56 GHz) at a thickness of 4.7 mm was achieved, covering essential 5G communication bands.
• The composite demonstrated outstanding anticorrosion performance, evidenced by a positive corrosion potential (-0.09 V vs AgCl) and a low corrosion current density (1.66 × 10⁻⁶ A·cm⁻²).

Conclusions:

• The developed core-shell SiC@CoNi/C composite effectively addresses the limitations of single-component absorbers for low-frequency electromagnetic wave absorption.
• The synergistic effect between the SiC core and the bimetallic MOF-derived carbon shell enhances polarization, scattering, and charge transport, optimizing impedance matching and loss mechanisms.
• This work presents a promising design strategy for multifunctional materials that offer reliable electromagnetic wave absorption and environmental durability in challenging conditions, crucial for future communication technologies.