An industrial feasible and sustainable method for preparing fiberized bamboo-derived magnetic biomass carbon

With the progress of science and technology and the improvement of people's living standards, the high-value utilization of waste bamboo materials and the increasingly serious problem of electromagnetic wave (EMW) pollution have attracted more and more attention. The above two problems can be solved simultaneously by overcoming the structural defects of bamboo, such as dense arrangement of fiber cells, horizontal gradient stratification and so on, realizing the impregnation of inorganic materials, and then obtaining magnetic biochar-based EMW absorbers by in situ pyrolysis. Here, we carry out fibrosis treatment to obtain bamboo bundles with significantly increased specific surface area and a large number of exposed inner walls of fiber cells. After that, the bamboo bundles are impregnated in iron acetylacetonate (Fe(acac)(3)) DMF solution with concentrations of 0.04, 0.08 and 0.12 g/mL, and fiberized bamboo-derived magnetic biomass carbon (FBMC) are finally prepared through in situ pyrolysis technology. The results show that the EMW absorption performance of the prepared FBMCs is best with an impregnation concentration of 0.04 g/mL, and the minimum reflection loss is - 28.21 dB at 13.40 GHz with a matching thickness of 3 mm. With further increase of the impregnation concentration, the magnetic properties and electrical conductivities of FBMCs are enhanced, but their corresponding EMW absorption performance is deteriorated. Further research shows that the absorption capacities mainly come from the good dielectric loss caused by the interfacial polarization effect, and the magnetic loss caused by natural and exchange response. It is proved that the attenuation ability of FBMC-0.04 to EMW energy mainly comes from EMW absorption behavior.