Reduced graphene oxide/nonwoven fabric filled honeycomb composite structure for broadband microwave absorption

The prevalence of electromagnetic pollution in daily life has led to a rapid escalation in the demand for high-performance electromagnetic absorption and protection materials. Herein, a composite material consisting of reduced graphene oxide (RGO)/nonwoven absorbent was prepared and filled into honeycomb structures. The single-layer nonwoven/honeycomb composite, with a thickness of 5 mm, demonstrates an effective absorption bandwidth (reflection loss ≤ −10 dB) reaching 12.1 GHz (5.9 GHz–18 GHz) and a minimum reflection loss of −37 dB. This is attributed to the synergistic absorption effects of conduction loss, interfacial scattering, dielectric relaxation, and multiple scattering losses. Furthermore, the bilayer composite structure demonstrates the capability to achieve full band absorption of 2 GHz–18 GHz with a thickness of only 10 mm, giving carbon materials a thin and lightweight absorption effect. In addition, the composite materials exhibit excellent mechanical properties. This study presents a new idea for the design and manufacture of broadband, lightweight, and high-performance microwave absorbers, which holds significant potential in the field of electromagnetic pollution prevention and absorption.