From waste to wealth: Crumb rubber@carbon nanotube/Fe3O4 composites towards highly effective electromagnetic microwave absorption with wide bandwidth

The reuse of the waste crumb rubber (CR) is of great significance to alleviate the increasingly serious black pollution problem. Herein, low-cost electromagnetic microwave absorption (EMA) CR composites assisted by conductive carbon nanotubes (CNTs) and magnetic Fe3O4 are fabricated with the aid of microwave. The effects of the addition of CNTs and Fe3O4 on the structure and morphology, and EMA properties of the CR@CNT/Fe3O4 composite are evaluated in detail. The resulted composite can exhibit a superior minimum reflection loss (RLmin) of −60.46 dB at 14.19 GHz with a thickness of 2.3 mm, and a wide effective absorption bandwidth of 5.5 GHz (11.2–16.7 GHz) due to the synergy effect of coordinated dielectric and magnetic losses, good interface impedance matching, and internal multiple reflections. This composite recycling from waste tire rubber is expected to become a potential candidate as a low-cost microwave absorber for reducing electromagnetic and black pollution. [Display omitted] •A CNT/Fe3O4 composite recycling from waste tire rubber.•The synergistic effect of electricity and magnetism for EMA.•Highly effective EMA properties of −60.46 dB with wide bandwidth of 5.5 GHz.