Electrospun Ni-doped ZnO nanofiber coatings on carbon fabric for enhanced electromagnetic interference shielding

Electromagnetic interference (EMI) is a critical concern in aerospace and defense applications, where lightweight structural composites must provide effective shielding against high-frequency electromagnetic (EM) radiation. In this work, Ni-doped ZnO (Ni-ZnO) nanofibers were directly deposited onto bidirectional carbon fabric substrates using an electrospinning process, followed by calcination at a high temperature. The nanofiber-coated fabrics were characterized for morphological, structural, and interfacial properties using scanning electron microscopy (SEM), X-ray diffraction (XRD), and Fourier-transform infrared spectroscopy (FTIR). The shielding effectiveness (SE) of the samples was evaluated in the X-band frequency range (8-12 GHz) using a vector network analyzer. The Ni-ZnO nanofiber coating enhanced the absorption-dominated shielding mechanism, resulting in improved attenuation performance compared to unmodified carbon fabric/epoxy laminates. The three-layer Ni-ZnO nanofiber-coated laminate achieved a maximum SE of ~ 85 dB at 10 GHz, corresponding to > 99.99% attenuation of incident EM radiation. This improvement is attributed to synergistic dielectric and magnetic losses, increased interfacial polarization, and enhanced conductive pathways. These findings demonstrate that Ni-ZnO nanofiber-modified carbon fabrics are promising for multifunctional aerospace composite structures requiring both mechanical performance and superior EMI shielding.