Nanostructures Composed of Dual Plasmonic Materials Exhibiting High Thermal Stability and SERS Enhancement

As one kind of alternative to conventional metals, titanium nitride offers many advantages in the rapidly growing fields of plasmonics and metamaterials. However, the development of TiN_x-based plasmonics is severally limited by the difficulty in the preparation. Herein, a facial approach is developed for the preparation of Au@TiN_x core-shell nanostructures. The synthesis starts with colloidal Au nanospheres, followed by the growth of amorphous TiO₂ shells. The obtained Au@a-TiO₂ nanostructures convert into Au@TiN_x through nitridation at high temperature in ammonia atmosphere. The prepared Au@TiN_x nanostructures have strong plasmonic scatting in the visible region and strong field enhancement at the surface of nanostructures. Au@TiN_x nanostructures also exhibit a relatively large enhancement for Raman scattering. The developed preparation method can produce TiN_x nanostructures with relatively uniform size and thus will be very helpful to the development of TiN_x-base plasmonics.