Open AccessSpaced Titania Nanotube Arrays Allow the Construction of an Efficient N‐Doped Hierarchical Structure for Visible‐Light Harvesting
Author(s) -
Nguyen Nhat Truong,
Ozkan Selda,
Tomanec Ondrej,
Zboril Radek,
Schmuki Patrik
Publication year - 2018
Publication title -
chemistryopen
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.644
H-Index - 29
ISSN - 2191-1363
DOI - 10.1002/open.201700199
Subject(s) - doping , nanotube , nanotechnology , materials science , visible spectrum , optoelectronics , carbon nanotube
Regularly spaced TiO 2 nanotubes were prepared by anodizing a titanium substrate in triethylene glycol electrolyte at elevated temperature. In comparison to conventional TiO 2 nanotubes, spaced nanotubes possess an adjustable spacing between the individual nanotubes; this allows for controlled buildup of a hierarchical nanoparticle‐on‐nanotube structure. Here, we use this principle for layer‐by‐layer decoration of the tubes with TiO 2 nanoparticles. The hierarchical structure after N doping and NH 3 treatment at 450 °C shows a significant enhancement of visible‐light absorption, although it only carries a low doping concentration of nitrogen. For optimized N‐doped and particle‐decorated spaced TiO 2 nanotubes, a considerable improvement in photocatalytic activity is obtained in comparison with conventional N‐doped TiO 2 nanotubes or comparable N‐doped nanoparticle films. This is attributed to an enhanced visible‐light absorption through the N‐doped nanoparticle shell and a fast charge separation between the shell and the one‐dimensional nanotubular core.