Enhanced Microwave Absorption by Incorporating Fe3O4 Nanoparticles into Ordered Mesoporous Carbon

Abstract

Novel Fe3O4/ordered mesoporous carbon (OMC) composite powders have been prepared by impregnation and reduction methods for the microwave absorbing application purpose. The Fe3O4nanoparticles were encapsulated in the mesopores of OMCs, and Fe3O4contents in the composite could be easily controlled by changing the concentration of ferric nitrate solution during the preparation. The Fe3O4/OMC composites show very excellent microwave absorbing properties with respect to pure OMC samples, in a frequency ranging of 8.2-12.4 GHz. A minimum reflection loss (RL) value of -32 dB at 11.35 GHz and a broader absorption band with the RL values under -10 dB are obtained when the thickness of samples is 1.6 mm. The enhanced microwave absorption of the Fe3O4/OMC nanocomposites is contributed to the better impedance match between dielectric loss and magnetic loss, which originates from the incorporation of magnetic species into OMC.