Preparation of Fe₃O₄/biomass derived porous carbon composites and microwave absorption properties

To obtain lightweight and efficient composite wave absorbing materials, Fe₃O₄/BPC (FOC) composites were prepared by solvothermal method using BPC material and Fe(NO₃)₃9H₂O as raw materials. By adjusting the content of BPC, the electromagnetic parameters of FOC composites can be effectively regulated. SEM and BET show that with the increase of BPC material content, a large number of heterogeneous interfaces are formed in the composites to increase the specific surface area, which can enhance the interfacial polarization ability of the composites. The minimum RL value of FOC-3 is −25.84 dB and the effective absorption bandwidth is 4.88 GHz at a thickness of 1.4 mm when the BPC material is added at 0.3 g. The wide absorption bandwidth is mainly attributed to the porous structure and the coordination between the electric and magnetic losses, which enhance the electromagnetic attenuation ability of the material.