Multiple interface coupling in halloysite/reduced graphene oxide/ cobalt nickel composites for high-performance...

Area of Science:

• Materials Science
• Nanotechnology
• Electromagnetism

Background:

• Developing advanced microwave absorbing materials is crucial for electromagnetic compatibility and shielding.
• Existing materials often face limitations in performance, bandwidth, or cost-effectiveness.

Purpose of the Study:

• To synthesize and characterize a novel halloysite nanotube/reduced graphene oxide/cobalt nickel composite (HNT/rGO/CoNi).
• To evaluate the electromagnetic absorption performance of the synthesized composite for potential microwave absorbing applications.

Main Methods:

• Co-precipitation and calcination were used for material synthesis.
• Characterization involved X-ray diffractometry, Raman spectroscopy, SEM, TEM, and XPS.
• Electromagnetic absorption was tested in the 2-18 GHz frequency range.

Main Results:

• The HNT/rGO/CoNi composite exhibited impressive electromagnetic absorption due to synergistic effects and good impedance matching.
• The optimized composite achieved a maximum reflection loss of -69.77 dB at 14.72 GHz.
• An effective absorption bandwidth of 7.12 GHz was obtained, covering 10.88-18.00 GHz.

Conclusions:

• The composite's performance stems from multiple loss mechanisms: interfacial polarization, dipole polarization, ferromagnetic resonance, and eddy currents.
• Halloysite nanotubes enhance nanoparticle dispersion and tune complex permittivity.
• This work presents a new strategy for fabricating high-performance microwave absorbers using natural components.