Modification of carbonized lignocellulose framework with FeNi-SnOx heterojunctions for enhanced electromagnetic...

Natural wood, a porous lignocellulosic resource, is an ideal precursor for carbon frameworks owing to its renewability. However, achieving a high electromagnetic shielding effectiveness poses a tremendous challenge for lignocellulose-based carbon framework. Herein, we developed a new material (FeNi-SnOx/CW) by embedding FeNi alloy and SnOx nanoparticles in carbonized lignocellulose framework (CW) from delignified wood using interface engineering modification. The CW acted as a conductive scaffold, while FeNi-SnOx enhanced polarization and magnetoelectric properties. Due to the synergistic effect of multiple mechanisms, the FeNi-SnOx/CW achieved excellent conductivity (437.3 S/m) and high saturation magnetization (13.33 emu/g). It also demonstrated a high EMI SE of 91.2 dB and a high ratio of SE_A/SE_T up to 85 % across the X-band at 2 mm thickness. Significantly, the interface engineering modification has resulted in a 59.2 dB enhancement in the EMI SE properties of the composite material compared to the pure CW (32.0 dB). Surface hydrophobicity modification with PDMS of the FeNi-SnOx/CW composite had a negligible impact on its EMI SE, thereby highlighting its practical potential. This research shows the benefits of FeNi-SnOx in boosting EMI shielding and offers a way to use renewable wood-based lignocellulose for high-performance EMI shielding materials.