The Thickness Effect on LSPR Spectra of Au-Nanorod Coated TiO2 and SiO2 Studied by MNPBEM

Autor: Dede Djuhana, Muhammad Sujak Mansur Kuddah, Miftahussurur Hamidi Putra
Rok vydání: 2019
Předmět:
Zdroj: IOP Conference Series: Materials Science and Engineering. 553:012016
ISSN: 1757-899X
1757-8981
DOI: 10.1088/1757-899x/553/1/012016
Popis: We have studied the effect on localized surface plasmon resonance (LSPR) of Au-nanorod (AuNR) coated TiO2 (Au@TiO2) and SiO2 (Au@SiO2). The length and diameter of AuNR are 70 nm and 20 nm, respectively. For this purpose, then AuNR was coated by TiO2 and SiO2 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 TiO2 faster than SiO2. Furthermore, we have also observed the peak of LSPR extinction curve of Au@TiO2 have a similar trend to Au@SiO2 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@TiO2 show more than one peak present around ∼2-3nm and ∼8nm. However, only one peak happened in Au@SiO2. In a sense, Au coated TiO2 can be fully utilized to enhance photocatalytic activity under visible light of AuNR and useful in photocatalytic activity, on the other hand, SiO2 plays an insignificant role for a certain limit thickness under visible light – near-infrared.
Databáze: OpenAIRE