Plasmonic MXene/Au@Ag core–shell heterostructures: a unified platform for electromagnetic stealth, antimicrobial action, and environmental remediation

The integration of electromagnetic wave absorption, antibacterial functionality, and environmental remediation into a single composite material remains a formidable challenge due to conflicting material property requirements. To address this, we fabricate plasmonic MXene/Au@Ag core–shell nanocomposites via in situ reduction, leveraging the synergistic effects of bimetallic architecture and MXene's tunable surface chemistry. The Au@Ag core–shell nanoparticles enhance interfacial polarization and plasmonic resonance, enabling ultra-broadband absorption (7.6 GHz effective absorption bandwidth) with a minimum reflection loss of −42.93 dB at 2.8 mm thickness, alongside a 42.9 dB m2 radar cross-section reduction. Concurrently, the composite exhibits >95% antibacterial efficiency via Ag+ release and light-triggered ROS generation, alongside >90% adsorption capacity for organic pollutants through MXene's functionalized surface. By unifying electromagnetic stealth, antimicrobial action, and environmental remediation, this work establishes a versatile platform for next-generation composites in aerospace, biomedical, and environmental engineering.