Synthesis of free-standing carbon nanotube buckypaper films decorated with Fe3O4 nanoparticles and polyaniline as highly effective electromagnetic shielding materials

• Free-standing buckypaper films decorated with Fe3O4 nanoparticles and polyaniline (BPFP) were synthesized via a simple two-step method, achieving a balance between electrical and magnetic properties. • The BPFP films exhibited absorption-dominated electromagnetic interference shielding effectiveness of 36.4 dB across 5.85-18 GHz, which is 17.0% higher than pristine buckypaper. • The incorporation of Fe3O4 and polyaniline enhanced both magnetic and dielectric losses through increased interfacial polarization and anisotropy energy. • The composite films retained the tensile strength, flexibility, and lightweight nature of buckypaper, making them promising for next-generation electromagnetic shielding applications.