Open AccessThe Thickness Effect on LSPR Spectra of Au-Nanorod Coated TiO2 and SiO2 Studied by MNPBEM
Author(s) -
Muhammad Sujak Mansur Kuddah,
Miftahussurur Hamidi Putra,
Dede Djuhana
Publication year - 2019
Publication title -
iop conference series. materials science and engineering
Language(s) - English
Resource type - Journals
eISSN - 1757-899X
pISSN - 1757-8981
DOI - 10.1088/1757-899x/553/1/012016
Subject(s) - materials science , nanorod , surface plasmon resonance , longitudinal mode , refractive index , extinction (optical mineralogy) , visible spectrum , nanotechnology , analytical chemistry (journal) , optoelectronics , optics , nanoparticle , chemistry , wavelength , physics , chromatography
We have studied the effect on localized surface plasmon resonance (LSPR) of Au-nanorod (AuNR) coated TiO 2 (Au@TiO 2 ) and SiO 2 (Au@SiO 2 ). The length and diameter of AuNR are 70 nm and 20 nm, respectively. For this purpose, then AuNR was coated by TiO 2 and SiO 2 with thickness varying from 2nm to 20nm with increment 2nm. The LSPR exhibited two modes, transverse mode (TM) and longitudinal mode (LM) as commonly was found in a rod-shaped particle. Interestingly, the peak of extinction red-shift as the thickness increased both TM and LM. Increasing volume and refractive index around AuNR contributed to red-shift, therefore the rate of decreasing energy TiO 2 faster than SiO 2 . Furthermore, we have also observed the peak of LSPR extinction curve of Au@TiO 2 have a similar trend to Au@SiO 2 as the thickness increased, but its beginning to decrease at ∼8nm. In the LM, for a given thickness, we found the peak of extinction curve Au@TiO 2 show more than one peak present around ∼2-3nm and ∼8nm. However, only one peak happened in Au@SiO 2 . In a sense, Au coated TiO 2 can be fully utilized to enhance photocatalytic activity under visible light of AuNR and useful in photocatalytic activity, on the other hand, SiO 2 plays an insignificant role for a certain limit thickness under visible light – near-infrared.