Synthesis and electromagnetic interference shielding of cellulose-derived carbon aerogels functionalized with α-Fe₂O₃...

Eco-friendly cellulose-derived carbon aerogels (CDCA) were employed as porous substrate to integrate with α-Fe₂O₃ and polypyrrole (PPy) via pyrolysis and vapor-phase polymerization. The SEM and TEM observations present that the wrinkled PPy sheets and the α-Fe₂O₃ nanoparticles were well dispersed in CDCA. The strong interactions (such as hydrogen bonding) between the substrate and the nanomaterials were demonstrated by the FTIR and XPS analysis. When utilized as electromagnetic interference (EMI) shielding materials, the α-Fe₂O₃/PPy/CDCA (FPCA) composite has the highest total shielding effectiveness (SE_total) of 39.4dB, about 2.0, 2.9, and 1.3 times that of the acid-treated CDCA (19.3dB), PPy (13.6dB), and α-Fe₂O₃/CDCA (29.3dB), respectively. Moreover, the shielding effectiveness due to absorption accounts for 78.2%-84.2% of SE_total for FPCA, indicative of the absorption-dominant shielding mechanism contributing to alleviating secondary radiation. These features make the composite a useful alternative candidate for EMI shielding.