Ultrathin Two-Dimensional BiOCl-Bi₂ S₃ -Cu₂ S Ternary Heterostructures with Enhanced LSPR effect for NIR Photonic...

Photonic disinfection, particularly near-infrared (NIR) light triggered antibacterial, has emerged as a highly promising solution for combating pathogenic microbes due to its spatiotemporal operability, safety, and low cost of apparatus. However, it remains challenging to construct NIR-responsive antibacterial agents with high light-converting efficacy and elucidate synergistic mechanisms. In this work, ultrathin two-dimensional (2D) BiOCl-Bi₂ S₃ -Cu₂ S ternary heterostructures that can efficiently kill drug-resistant bacteria were synthesized by doping 0D Bi₂ S₃ and Cu₂ S nanoparticles in the 2D BiOCl nanosheets via a facile one-pot hydrothermal method. Notably, the incorporation of Cu₂ S nanoparticles bestows strong NIR light-harvesting capability to the composite nanosheets due to their localized surface plasmon resonance (LSPR). Upon NIR light illumination, the BiOCl-Bi₂ S₃ -Cu₂ S nanosheets can achieve enhanced photonic hyperthermia and reaction oxygen species (ROS) generation, serving as single light-activated bi-functional photothermal/photodynamic therapeutics. High-speed hot electrons and large local electronic fields caused by LSPR might play an important role in thermal vibrations and effective carrier separations, respectively. Benefiting from the unique ternary heterostructures, both the photothermal conversion and ROS generation efficacy of BiOCl-Bi₂ S₃ -Cu₂ S nanosheets are significantly improved compared to the binary BiOCl-Cu₂ S or BiOCl-Bi₂ S₃ nanosheets. Accordingly, the ternary composite nanosheets can effectively kill bacteria via the NIR-driven photonic disinfection mechanism. This work presents a new type of 2D composite nanosheets with ternary heterostructures for NIR photonic disinfection.