A universal NTA chelation-derived strategy to develop triple-functional core@shell magnetic carbon nanorods for microwave absorption, antibacterial, and anticorrosion applications

Simultaneous achievement of high-performance microwave absorption, antibacterial activity, and corrosion resistance remains a key challenge for multifunctional materials in real-world application scenarios. Herein, one-dimensional core@shell FeCo@carbon nanorods (CNRs), FeCoNi@CNRs, and FeCoNiMn@CNRs consisting of magnetic alloy nanoparticles as core confined in the shell of CNRs are fabricated through a nitrilotriacetic acid chelation (NTAC)-assisted hydrothermal route, phenolic-resin coating, and carbonization treatment. The increased annealing temperature promotes graphitization of carbon shell, yielding the improved impedance matching and dielectric/magnetic synergy. The optimized FeCoNi@CNRs deliver a minimum reflection loss of -52.57 dB and an effective absorption bandwidth (EAB) of 5.60 GHz. Successive Ni and Mn incorporation further enhances complex permittivity, attenuation constant, and impedance matching. The acquired FeCoNiMn@CNRs display an EAB of 6.40 GHz, a radar cross-section reduction up to 39.59 dB·m², a bacteriostatic rate approaching 100% against E. coli, and the highest corrosion potential with the lowest corrosion current density in simulated seawater. The functionally complementary core@shell design with magnetic alloy core for loss/ROS generation and graphitic carbon shell for interfacial polarization/barrier protection establishes a facile and universal NTAC-derived strategy for advanced wave-absorbing materials with integrated antibacterial and environmental durability.