Au@TiN Hybrid Nanostructures with Geometric, Compositional, and Optical Tunability
Developing plasmonic nanomaterials with compositions beyond noble metals is crucial for expanding their applications. Transition metal nitrides, such as titanium nitride (TiN), exhibit excellent plasmonic optical properties and photothermal conversion efficiency, showing promise in catalysis, photothermal therapy, and seawater desalination. However, the structure-property relationship governing their plasmonic optical properties remains unclear. Here, we constructed Au@TiN core-shell nanostructures and systematically investigated the tunability of their geometry, composition, and optical properties. By varying the Au core size and TiN shell thickness, we achieved precise control over the localized surface plasmon resonance (LSPR) from visible to near-infrared wavelengths. Single-particle scattering spectroscopy revealed distinct plasmon hybridization modes, with experimental spectra matching theoretical simulations. The Au@TiN nanostructures exhibited enhanced photothermal conversion efficiency (η = 78.5%) under 808 nm laser irradiation, significantly outperforming pure TiN nanoparticles (η = 45.2%). This work demonstrates multi-factor control over plasmonic effects in TiN, providing insights for designing TiN-based plasmonic nanomaterials for catalysis and sensing.