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 <i>via in situ</i> 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 <i>via</i> 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.