Self-supporting flexible bifunctional microwave absorbing and corrosion resistant of three-dimensional porous bamboo/NiFeSiAl/CNTA

FeSiAl (FSA)-based alloys demonstrate superior potential as microwave-absorbing agents. However, optimizing the balance between impedance matching and corrosion resistance remains a significant challenge. In this study, we present a simple approach to synthesize self-supporting and flexible microwave absorbers by incorporating bamboo (B) powders into FSA-based alloys. Ni doping in the FSA alloy (NFSA) was employed to enhance the impedance matching and corrosion resistance of the system. Additionally, carbon nanotube arrays (CNTA) were chemically vapor-deposited on the surface of NFSA to further improve electromagnetic wave absorption performance. The B-NFSA/CNTA composite exhibited a minimum reflection loss ( RL min ) of −49.12 dB at 12.0 GHz and a broad effective absorption bandwidth ( EAB max ) of 4.81 GHz at a thickness of 1.53 mm. Corrosion resistance tests revealed that both B-FSA and B-NFSA/CNTA composites demonstrated significantly enhanced corrosion resistance, attributed to the protective barrier provided by the biomass bamboo film. The corrosion current densities of B-FSA and B-NFSA/CNTA increased by two orders of magnitude compared to FSA, reaching 4.41 × 10 −7 A∙cm −2 and 7.38 × 10 −7 A∙cm −2 , respectively. Therefore, these flexible biomass-based composites show great potential for applications in microwave absorption and corrosive environments.