Abstract
Conventional approaches to improve electromagnetic wave absorption (EMWA) performance of biomass-derived carbon (BDC) materials through incorporation of magnetic/dielectric components frequently encounter challenges of complex synthesis processes and poor stability. To address these challenges, this study utilizes scallion-derived carbon with an ultrahigh specific surface area (833.15 m²/g) as a precursor and develops two distinct methods to enhance dielectric loss. The freeze-drying BDC exhibits exceptional EMWA properties, achieving an effective absorption bandwidth (EAB) of 5.79 GHz and a minimum reflection loss (RLmin) of −71.9 dB. Meanwhile, boron-doping BDC delivers an even broader EAB of 6.15 GHz with an RLmin of −49.7 dB. Furthermore, first-principles calculations systematically investigate the role of boron doping in enhancing EMWA performance. Both experimental tests (including Tesla coil demonstrations) and theoretical simulations (such as far-field analysis) are conducted to validate the absorption mechanisms. This study not only offers fundamental guidance for designing sustainable and high-efficiency EMWA materials from renewable resources but also demonstrates their promising applications in electromagnetic interference shielding and thermal management systems, underscoring the versatility of BDC materials for solving contemporary technological problems.
[Display omitted]
•The scallion-derived carbon has an ultrahigh specific surface area of 833.15 m²/g after annealing at 900°C.•Freeze-drying and boron doping both enhance BDC’s electromagnetic wave absorption.•This study systematically reveals boron doping’s role in boosting BDC’s EMWA via first-principles calculations.•The prepared BDC shows promise for EMW shielding and thermal management.