Dual template-derived 3D porous Co₆Mo₆C₂/Mo₂C@NC framework for electromagnetic wave response and multifunctional applications

The swift advancement of electronics technology has led to a burgeoning interest in multifunctionalizing electromagnetic wave (EMW) absorption materials as a prospective avenue for future development. However, the effective integration of diverse functions within a single material continues to present challenges. This work successfully fabricated a three-dimensional (3D) porous Co₆Mo₆C₂/Mo₂C@NC framework with carbon microspheres through uncomplicated freeze-drying and high-temperature pyrolysis techniques. The resultant magnetic bimetallic carbide (Co₆Mo₆C₂ and Mo₂C) nanoparticles are uniformly and densely embedded within the carbon layer, facilitated jointly by a rigid template (molybdenum salt) and a flexible template (glucose), thus realizing an exceptional dual loss mechanism involving dielectric and magnetic components. The establishment of the 3D porous conductive network enhances EMW absorption through multiple reflections and scattering mechanisms. Impressively, the Co₆Mo₆C₂/Mo₂C@NC framework attains remarkable EMW absorption characteristics with ultralightweight (0.1567 g cm^–3), ultrathin matching thickness (1.7 mm), and robust absorption (reflection loss R_L value of –65.89 dB). Furthermore, it achieves a noteworthy effective absorption bandwidth (EAB, R_L ≤ –10 dB) spanning 6.4 GHz, ensuring complete absorption of 100 % within the X band (8–12 GHz) at a matching thickness of 2 mm. In addition, the Co₆Mo₆C₂/Mo₂C@NC framework exhibits pronounced hydrophobicity and magnetic responsiveness, bestowing upon it appealing attributes including self-cleaning, flame retardancy, and thermal insulation, on par with those observed in commercial products. The radar cross-sectional area (RSC) reduction value of the Co₆Mo₆C₂/Mo₂C@NC framework can reach 35.2 dB m² by RSC simulation, which can effectively lower the likelihood of detection by radar detectors for the target. This study presents a viable strategy for the advancement of novel lightweight and multifunctional materials that demonstrate exceptional performance in absorbing electromagnetic waves.