A facile precursor pyrolysis route to bio-carbon/ferrite porous architecture with enhanced electromagnetic wave absorption in S-band

Bio-carbon has been deemed as a promising species of electromagnetic wave absorption materials for stealth material due to its unique pore structure and light weight as well as abundant available crude materials such as plants. In this paper, bio-carbon/ferrite porous architecture is prepared by a facile precursor pyrolysis route to acquire a light weight absorbent using natural bamboo and Fe(NO₃)₃ as the precursors. The product can be directly synthesized in a tube furnace at 800–1000 °C under nitrogen atmosphere protection. The minimum reflection loss (RL) can be tailored ranging from −43.2 dB at 17.6 GHz (the band width below −10 dB is 13.6 GHz, from 4.4 to 18.0 GHz) to −21.9 dB at 14.6 GHz (the band width below −10 dB is 6.4 GHz, from 11.6 to 18.0 GHz) by controlling the annealing temperature. The enhanced and frequency-adjustable EM absorption properties are provable determined by the coordination of complex permittivity and relative magnetic permeability of the composite carbon/ferrite.