Preparation and Microwave-Absorption Performance of Fe₃O₄/Carboxymethyl Cellulose/Graphene Oxide Composite Materials

In order to obtain graphene composite materials with good microwave absorption performance, Fe₃O₄ particles were prepared by a coprecipitation method, and then combined with carboxymethyl cellulose (CMC) to prepare Fe₃O₄/CMC particles. Then, Fe₃O₄/CMC was successfully combined with graphene oxide (GO) through ultrasonic oscillation to prepare Fe₃O₄/CMC/GO composite materials. The structures and morphologies of the materials were characterized by x-ray diffraction (XRD), Raman spectroscopy, and scanning electron microscopy (SEM), and the results showed that spherical Fe₃O₄/CMC particles were uniformly distributed on the surface of GO. The electromagnetic parameter testing of Fe₃O₄/CMC/GO composite materials in the range of 2–18 GHz revealed that the magnetic loss mechanism was mainly natural resonance loss and exchange resonance loss. What is more, its microwave absorption performance was calculated by using line transmission theory. The microwave absorption performance of the composite showed that the composite had excellent microwave absorption ability when the weight ratio of Fe₃O₄/CMC to GO was 3:1. When the thickness of the composite material was 3.5 mm, the minimum reflection loss reached − 36.82 dB, indicating that over 99.9% of the microwaves were absorbed by the composite material, and that the effective absorption bandwidth was 6.10–8.52 GHz, reaching 2.42 GHz.