Design and synthesis of Rh nanoparticle-decorated Ag2S nanostructures for enhanced near-infrared photothermal and photocatalytic antibacterial applications

Abstract

This study reports the synthesis of Ag₂S/Rh nanostructures for enhanced antibacterial activity through combined photothermal and photocatalytic mechanisms under near-infrared (NIR) irradiation. The nanoparticles were prepared using a facile deposition method and characterized by XRD, TEM, and XPS. Photothermal experiments demonstrated rapid and efficient temperature elevation under NIR light, with Rh decoration significantly enhancing photothermal conversion. Antibacterial activity against S. pyogenes and P. aeruginosa was evaluated, showing near-complete bacterial inactivation under optimized conditions. Mechanistic investigations confirmed that hydroxyl (˙OH) and superoxide (O₂˙⁻) radicals, generated via photocatalysis, synergistically enhance bacterial inhibition. ESR spectra provided direct evidence of ROS production, correlating with reduced bacterial viability. These findings highlighted the potential of Ag₂S/Rh composites as advanced materials for combating drug-resistant pathogens via NIR-driven photothermal and photocatalytic mechanisms.