One-dimensional C/Co composite nanofibers derived from ZIF-67 with excellent wideband electromagnetic microwave absorption performance

Abstract

The rapid advancement of wireless communications, radar systems, and electronic devices has resulted in a substantial increase in electromagnetic interference (EMI), which poses a threat to electronic device performance and human health. This study addresses the urgent need for lightweight materials with strong absorption capacities, wide absorption bandwidths, and low thickness values. For this purpose, ZIF-67-derived C/Co nanofibers were synthesized via electrospinning, dipping, and high-temperature carbonization. Co²⁺ ions were pre-anchored and encapsulated in polyacrylonitrile (PAN) fibers and are grown by immersion in an organic ligand. Utilizing 0.4 g of cobalt nitrate hexahydrate, the amount of encapsulated Co²⁺ was optimized to provide the greatest electromagnetic wave absorption performance. Under these conditions, the reflection loss was −49.45 dB, and the maximum effective absorption bandwidth was 6.48 GHz, thereby covering the entire Ku band. The composite material demonstrated a significant improvement in impedance matching and electromagnetic wave dissipation, which was attributed to the uniform dispersion of Co particles and the formation of multi-component heterogeneous interfaces. This study presents a pragmatic method for creating high-performance materials that could potentially reduce electromagnetic interference (EMI) in the aerospace, telecommunications, and defense sectors.