The increasing electromagnetic radiation poses a serious hazard to electronic devices, human health, and the environment. Carbon-based materials derived from biomass are considered to have excellent electromagnetic absorption potential due to their high porosity, low density, strong dielectric loss, wide source availability, and low cost.

This study aims to analyze the electromagnetic wave absorption characteristics of biomass-derived carbon-based materials.

This study is based on hydrothermal and carbonization processes, using loofah as the carbon precursor, and introducing NiCo₂O₄ magnetic particles to prepare NiCo₂O₄/C (NCO) electromagnetic wave absorbing material, with its actual wave-absorbing performance verified through COMSOL simulation software.

The introduction of NiCo₂O₄ particles not only enhanced the magnetic loss properties of the composites, but also regulated the dielectric properties and optimized the impedance matching. Due to the unique mesh structure and the synergistic effect of interfacial polarization, conductive loss, magnetic loss and other loss mechanisms, the NiCo₂O₄/C composites obtain good electromagnetic wave absorption properties, with the strongest reflection loss of −47.46 dB, and the widest absorption band of 5.68 GHz (12−17.68 GHz), which covers almost the entire Ku-band. In addition, the study also demonstrated that NCO-2 composites have some practical applications through RCS simulations.

The synergistic effect of dielectric and magnetic properties can significantly modulate the dielectric properties of composites, optimize impedance matching, and enhance loss mechanisms, thereby achieving excellent electromagnetic wave absorption performance. This work provides a theoretical and experimental basis for the development of green and sustainable high-performance biomass-derived carbon-based composites.