Electronic Delocalization of Fe Atom-Cluster for Long-Term Stable Electromagnetic Wave Absorption in Marine...

High-performance electromagnetic wave (EMW) absorbers with environmental adaptability are essential for advanced maritime stealth and electromagnetic protection. Herein, we design a synergistic absorber integrating Fe clusters (Fe_AC) and single atoms (Fe_SA) to tackle the issue of EMW attenuation under high-salinity and humidity marine conditions. First-principles calculations and experiments reveal that Fe_AC and Fe_SA anchored on a π-conjugated carbon support form a delocalized electronic space that enables long-range electronic interactions and multicenter synergistic coupling. This electronic synergy markedly strengthens conduction loss and dipolar polarization, delivering a minimum reflection loss of - 68.78 dB and an effective absorption bandwidth of 6.00 GHz at a low loading of 6 wt%. Notably, Fe_AC exhibits a thermodynamically preferred adsorption toward Cl^-, generating locally enriched negative-charge regions that mitigate direct ionic attack on atomically dispersed Fe_SA sites and thereby suppress corrosion-induced performance degradation. In addition, the absorber film demonstrates mechanical flexibility and thermal insulation, highlighting its potential for durable and high-efficiency maritime EMW protection applications.