Fe–Fe3C/C microspheres as a lightweight microwave absorbent†
Abstract
As electromagnetic pollution is becoming more and more serious, novel composite microwave absorbents are gaining much attention. In this work, low-cost glucose was used as a carbon source to prepare hydrochar, and Fe–Fe3C/C microspheres for microwave absorption were successfully synthesized through the hydrothermal synthesis of Fe3O4/hydrochar and subsequent high-temperature carbonization at different temperatures. The results showed that the Fe–Fe3C nanoparticles were uniformly loaded on the carbon microspheres. Resulting from the synergistic effect of Fe–Fe3C nanoparticles and partially graphitized carbon, a wide region of microwave absorption was achieved due to dual dielectric and magnetic losses. An effective bandwidth of reflection loss less than −10 dB could reach up to 4 GHz with 1.5 mm thickness. Owing to the characteristics of the cost-effective synthetic route, low density and good microwave absorption with thin thickness, the Fe–Fe3C/C microspheres could be used as a lightweight and highly efficient microwave absorbent.