Facile fabrication of exfoliated g-C3N4/MWCNTs/Fe3O4 ternary composites with multi-component functional synergy for high-performance microwave absorption

Abstract

Constructing multi-component materials with dielectric–magnetic synergy effects has been a significant focus of recent works to enhance microwave absorption efficiency. Herein, a top-down exfoliation strategy for forming carboxylated g-C₃N₄ (CCN) was demonstrated to achieve rich interfaces and enhanced interface compatibility. The abundant defects and functional groups (–COOH, –OH, C–O, and CO) of CCN enhanced the dipole polarization. Furthermore, MWCNTs and Fe₃O₄ were facilely decorated onto the surface of CCN by the general co-precipitation method to form CCN/C-Fe₃O₄ composite absorbers with multiple heterogeneous interfaces and attenuation mechanisms. Changing the content of CCN, CN/C-Fe₃O₄ exhibits excellent wave absorption and impedance matching characteristics with a minimum reflection loss value (RL_min) of −51.74 dB at only 1.9 mm (11.12 GHz), and the efficient absorption bandwidth can reach up to 4.28 GHz at 1.4 mm. This work reveals how CCN enhanced the synergistic balance between the dielectric–magnetic loss in composites. It also provides a new idea for the facile synthesis of novel multi-component composites for high-performance microwave absorption.