MOFs-derived flower-like cobalt@carbon multiscale hierarchical composites with effective microwave absorption in the low frequency range

• A novel flower-like Co@C/CF hierarchical composite was synthesized via in-situ growth of Co-MOFs on carbon fibers followed by annealing, achieving a minimum reflection loss of −55.7 dB at 6–8 GHz with a thickness of 2.8 mm. • The effective absorption bandwidth (EAB) reached 3.24 GHz in the 12–16 GHz range at a thin thickness of 1.5 mm, demonstrating tunable absorption across low and high frequency bands. • The flower-like structure, combined with magnetic cobalt nanoparticles, significantly improved impedance matching and induced multiple reflection losses, enhancing microwave absorption performance. • This work offers a convenient and scalable method for designing structural–stealthy composites with integrated hierarchical architectures, promising for advanced electromagnetic pollution control and military stealth applications.