Rice husk derived porous carbon embedded with Co3Fe7 nanoparticles towards microwave absorption

For eliminating electromagnetic pollution caused by harmful electromagnetic waves, it is urgent to develop electromagnetic absorption materials with strong refection loss and wide bands. In this study, the rice husk was employed as raw material to prepare lightweight and high specific surface area porous carbon (RHC). Subsequently, using RHC as the carrier, the RHC@Co3Fe7 nanocomposites were obtained by embedding Co3Fe7 nanoparticles into the pore of the RHC. Under the synergistic influence of the multiple reflection/scattering of porous structure, magnetic resonance of Co3Fe7 nanoparticles, as well as electron polarization aroused by the heterogeneous interface between RHC and Co3Fe7 , the minimal reflection loss (RLmin) of the optimal product reaches to-68.106 dB at 16.24 GHz with the matching thickness of 1.44 mm. Meanwhile, for the optimal sample, the widest effective absorption bandwidth (EAB) is nearly 5 GHz covering the frequency range of 10.96-15.92 GHz at a matching thickness of 1.79 mm. The excellent absorption performance of RHC@Co3Fe7 nanocomposites may provide a new strategy for the preparation of lightweight, thin thickness, strong absorption and wide bandwidth material.