Synthesis of Fe3O4/carbon foams composites with broadened bandwidth and excellent electromagnetic wave absorption performance

Fabricating of bio-derived electromagnetic wave absorbing materials has become hotspot. However, many bio-derived absorbers still suffer from thicker matching thickness limiting their application. Herein, porous carbon foams derived from fish skin have been synthesized through a simple hydrothermal method for the first time. Then Fe3O4 nanospheres with diameter of 30 nm were uniformly imbedded into the carbon matrix via refluxing and annealing treatment. By controlling the precursor ratio of Fe(NO3)3·9H2O and carbon, optimized microstructure and component can be easily realized. As expected, the novel Fe3O4/C foams show outstanding electromagnetic wave absorption performance compared with single carbon foams. When the loading filler ratio was 25 wt%, the minimum RL value of FC-3 can reach −47.3 dB with a small matching thickness of 1.9 mm. Moreover, the effective absorption bandwidth was 5.68 GHz (12.16–17.84 GHz) with the thickness of 2.2 mm. The thin matching thickness could ascribe to the addition of Fe3O4 nanospheres which could introduce more dielectric loss and magnetic loss. Moreover, the matching thickness of FC-3 is much thinner than other reported bio-derived materials. This investigation could be a perspective paving for the fabrication and mechanism research of electromagnetic wave absorber derived from animal organs.