Carbon nanotube arrays catalyzed by NiFeSiAl in chemical vapor deposition and hybridized with silica for microwave absorption and anti-corrosion

Developing microwave absorbing materials that stably operate under high humidity and salt spray while maintaining durability remains a significant challenge. A novel NiFeSiAl/carbon nanotube array/SiO 2 (NFSA/CNTA/S) composite with dual microwave absorption and anti-corrosion functionalities is developed via a coupled catalytic chemical vapor deposition (CCVD) and sol-gel strategy. Ball-milled NFSA flakes act as both catalyst and magnetic component, while vertically aligned CNTA grown via CCVD enhance dielectric loss and form a conductive network. Magnetic losses from NFSA (hysteresis, eddy current, natural resonance) and dielectric losses from CNTA (conductivity, interface polarization) achieve broadband absorption. SiO 2 coating improves impedance matching and reduces corrosion current to 2.651 × 10 −7 A/cm 2 . The composite reaches a minimum reflection loss (RL min ) of −42.36 dB and effective absorption covering a substantial portion of the X and Ku bands. This coupled CCVD with sol-gel approach provides a pathway for designing novel NFSA/CNTA/SiO 2 hybrids with high-performance microwave absorption and anti-corrosion.