Activated carbon fiber/Fe₃O₄ composite with enhanced electromagnetic wave absorption properties

Area of Science:

• Materials Science
• Electromagnetics
• Nanotechnology

Background:

• Electromagnetic wave absorption is crucial for shielding applications.
• Activated carbon fiber (ACF) materials offer potential for wave absorption.
• Enhancing the absorption bandwidth and efficiency of ACF is a key challenge.

Purpose of the Study:

• To synthesize a low-density activated carbon fiber/Fe3O4 composite (ACF/Fe3O4).
• To investigate the electromagnetic wave absorption properties of the ACF/Fe3O4 composite.
• To evaluate the potential of this composite for electromagnetic shielding applications.

Main Methods:

• Preparation of ACF/Fe3O4 composite using an in situ reduction method.
• Characterization of Fe3O4 nanoparticle size and distribution via scanning electron microscopy.
• Measurement of electromagnetic wave absorption using the arch method over 8.2-18 GHz.

Main Results:

• Fe3O4 nanoparticles (10-40 nm) were uniformly dispersed on the ACF surface.
• The ACF/Fe3O4 composite exhibited superparamagnetic behavior at room temperature.
• ACF/Fe3O4 showed significantly enhanced absorption: max reflectivity -30.07 dB, effective bandwidth 8.62 GHz (9.38-18 GHz), compared to ACF alone (max reflectivity -12.9 dB, bandwidth 1.9 GHz).

Conclusions:

• Coating ACF with nano-Fe3O4 magnetic particles effectively improves electromagnetic wave absorption.
• The ACF/Fe3O4 composite demonstrates superior performance for wideband microwave absorption.
• This composite material holds great potential for practical electromagnetic shielding applications.