Gold–Silver Hybrid Nanostructures for Efficient Near-Infrared Photothermal Conversion: Core–Shell Configuration of Multipod and Hollow Cage

Gold–silver hybrid nanostructures have emerged as promising candidates for efficient near-infrared (NIR) photothermal conversion due to their unique optical and electronic properties. In this study, we report on the synthesis and characterization of gold–silver core–shell nanostructures with Au multipods as the core and Ag hollow cage as the shell, exhibiting strong absorption in the NIR region, which is attributed to the coupled localized surface plasmon resonance (LSPR) effect. Benefiting from its large surface area and porous structure, an optimized photothermal conversion efficiency of 68.5% is achieved, evaluated using a water suspension under an 808 nm laser at a power density of 1.0 W cm–2. The photothermal stability was also investigated, revealing good durability after multiple cycles of heating and cooling. Our study demonstrates the potential of gold–silver core–shell hybrid nanostructures involving both multipods and hollow cages for efficient NIR photothermal conversion applications. These findings pave the way for further optimization of these nanostructures for various biomedical and industrial applications.