KTN@Ag nanorods：Synthesis and their wide controllable range for the local surface plasmon

Abstract

This work demonstrated the wide controllable range of the Local Surface Plasmon Resonance (LSPR) characteristic peak of the KTax-1NbxO3@Ag (KTN@Ag). KTN@Ag nanocubes (KTN@Ag NCs) and KTN@Ag nanorods (KTN@Ag NRs) with different Ag loading rate have been prepared. Compared with KTN@Ag NCs, the LSPR characteristic peak of KTN@Ag NRs showed a wider controllable range and the enhanced factor could reach 5.48. This result could be derived from the higher aspect ratio of KTN@Ag NRs, resulting in an enhanced the coupling effect between KTN and Ag. This viewpoint could also be verified by the FDTD (Finite-Difference Time-Domain) calculation. With the increase of Ag loading rate, the coupling between KTN and Ag was weakened. And the characteristic peak of KTN@Ag show a blue shift, which shifts to the characteristic peak of Ag nanocrystal gradually. With the increase of Ag loading rate from 11 to 21 wt%, the LPSR characteristic peak of KTN@Ag NCs showed a blue shift from 569 to 547 nm, whereas peak for KTN@Ag NRs was shifted from 762 to 646 nm. This work combined the coupling effect of nanostructured KTN and Ag nanocrystals. And the anisotropy would be beneficial to broaden the LSPR controllable range of the characteristic extinction spectra of KTN@Ag. Considering the low price of KTN, the KTN@Ag NRs should be a promising material applied in optical detection devices.