A magnetic metal composite biomass carbon material with high efficiency and broadband wave absorbing property

With the rise of wireless communication technology, while bringing convenience to people’s lives, the problem of electromagnetic pollution has become increasingly serious; therefore, there is an urgent need to find a new type of absorbing material with strong absorption performance, wide absorption band, thin thickness, and light weight to improve people’s living environment. Biomass-derived porous carbon has attracted much attention as a dielectric loss absorbing material; through the simple technological process, the composite magnetic metal can achieve excellent impedance matching and high efficient broadband wave absorption performance. In this experiment, Eupatorium adenophora was used as the raw material, and the metal composite porous carbon material was obtained by compounding Fe metals through the impregnation process and pyrolysis. When the impregnation ratio is 9%, the simulated thickness is 3.5 mm, and the frequency is 3.55 GHz; the best reflection loss that can be achieved is − 41.272 dB. The optimal absorption frequency band is 2.64 GHz, and the strongest absorption frequency band can cover 66% of the S band. Meanwhile, the syngas with hydrogen content of 41.77% can also be obtained through Fe metal doping in the pyrolysis process, which has high utilization value and effectively enhances the high-value utilization of waste biomass.