Porous, magnetic carbon derived from bamboo for microwave absorption

Abstract

Designing lightweight, environmentally friendly and broadband electromagnetic wave (EMW) absorbers to solve the increasingly EM pollution problem has become a research hotspot. Carbon material, especially the graphitized carbon derived from the biomass which possessing highly porosity on the framework, has considered the extremely potential in electromagnetic absorption since the ultralow density, abundant dipoles and moderate dielectric value, however, lacking of magnetic property restricts the efficient and broad absorption. Herein, a biomass-derived porous graphite-like carbon (g-C) matrix with controllable magnetic component (α-Fe and Fe3O4) decoration are realized via one-step pyrolysis reaction The development absorber exhibits an excellent EMW absorption performance with largest |RLmin| value of 47.06 dB and widest effective absorption frequency width of 5.52 GHz at a fixed coating thickness as thin as 1.80 mm, which is attributed to the good conductive loss and dielectric loss capacities permitted by the synergistic effect of equivalent circuit conductive network, the optimized impedance matching, the dipoles polarization, defect polarization and interfacial polarization. This work provides a theoretical and experimental basis for developing a green and sustainable method for preparing bamboo-derived carbon-based composites, and applying such materials to the field of EM protection and EM pollution control.