Core-shell titanium dioxide - titanium nitride nanotube arrays with near-infrared plasmon resonances.

5 years ago

Core-shell titanium dioxide - titanium nitride nanotube arrays with near-infrared plasmon resonances.

Piyush Kar, Samira Farsinezhad, Abdelrahman Mostafa Askar, Thariq Shanavas, Karthik Shankar, Himani Sharma, Najia Mahdi

Titanium nitride (TiN) is a ceramic with high electrical conductivity which in nanoparticle form, exhibits localized surface plasmon resonances in the visible region of the solar spectrum. The ceramic nature of TiN coupled with its dielectric loss factor being comparable to that of gold, render it attractive for CMOS polarizers, refractory plasmonics, surface-enhanced Raman scattering and a whole host of sensing applications. We report core-shell TiO2-TiN nanotube arrays exhibiting localized surface plasmon resonance (LSPR) peaks in the range 775-830 nm achieved by a simple, solution-based, low cost, large area-compatible fabrication route that does not involve laser-writing or lithography. Self-organized, highly ordered TiO2 nanotube arrays were grown by electrochemical anodization of Ti thin films on fluorine-doped tin oxide-coated glass substrates and then conformally coated with a thin layer of TiN using atomic layer deposition. The effects of varying the TiN layer thickness and thermal annealing on the LSPR profiles were also investigated. Modeling the TiO2-TiN core-shell nanotube structure using a Bruggeman effective medium approximation coupled with Fresnel coefficients resulted in calculated optical spectra that closely matched the experimentally measured spectra. The resulting TiO2 - TiN core-shell nanotube structures also function as visible light responsive photocatalysts, as evidenced by their photoelectrochemical water-splitting performance under LED illumination using 400 nm, 430 nm and 500 nm photons.

Publisher URL: http://doi.org/10.1088/1361-6528/aaad58

DOI: 10.1088/1361-6528/aaad58