Open AccessElectronic state of nitrogen in doped titanium dioxide
Author(s) -
Haruka Funabiki,
Kazuchika Ozawa,
T. Sekiya
Publication year - 2019
Publication title -
journal of physics. conference series
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.21
H-Index - 85
eISSN - 1742-6596
pISSN - 1742-6588
DOI - 10.1088/1742-6596/1220/1/012014
Subject(s) - electron paramagnetic resonance , x ray photoelectron spectroscopy , titanium dioxide , titanium , nitrogen , valence (chemistry) , doping , materials science , irradiation , analytical chemistry (journal) , adsorption , inorganic chemistry , photochemistry , nuclear chemistry , chemistry , nuclear magnetic resonance , organic chemistry , nuclear physics , optoelectronics , metallurgy , physics
A yellow N-doped TiO 2 powder was prepared by the sol-gel method using titanium tetra-isopropoxide and hydrazine monohydrate. An EPR signal was induced by the irradiation of light with hv ≥ 2.2 eV to the yellow TiO 2 powder and the signal intensity gradually decreased in the dark. The EPR signal was due to thermally trapped carriers interacting with the doped N. The thermal activation energy of the trapped carriers was estimated to be 0.22 eV. XPS measurement was performed on the yellow powder as well as colorless and blue N-doped powders obtained by oxidation and reduction, respectively. The N1s bands at 399.5 eV can be assigned to nitrogen adsorbed on the surface. The atomic valence of nitrogen in the colorless, yellow and blue powders was positive, neutral and negative, respectively. The atomic valence of nitrogen in doped TiO 2 depends on the oxidation-reduction procedure.