Premium
Photoelectrochemical H 2 Generation from Suboxide TiO 2 Nanotubes: Visible‐Light Absorption versus Conductivity
Author(s) -
Mohajernia Shiva,
Hejazi Seyedsina,
Mazare Anca,
Nguyen Nhat Truong,
Schmuki Patrik
Publication year - 2017
Publication title -
chemistry – a european journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.687
H-Index - 242
eISSN - 1521-3765
pISSN - 0947-6539
DOI - 10.1002/chem.201702245
Subject(s) - suboxide , materials science , photocurrent , anatase , x ray photoelectron spectroscopy , water splitting , conductivity , photoconductivity , visible spectrum , analytical chemistry (journal) , electron paramagnetic resonance , chemical engineering , optoelectronics , photocatalysis , chemistry , nuclear magnetic resonance , biochemistry , physics , chromatography , silicon , engineering , catalysis
Abstract In the present work we report on the key factors dictating the photoelectrochemical (PEC) performance of suboxide titania (TiO x ) nanotubes. TiO x nanotubes were produced by a systematic variation of reduction heat treatments of TiO 2 in Ar/H 2 . The properties of the TiO x tubes were investigated by electron paramagnetic resonance (EPR), transmission electron microscopy (TEM), X‐ray photoelectron spectroscopy (XPS), solid‐state conductivity, reflectivity measurements, photocurrent spectroscopy, and photoelectrochemical hydrogen evolution. In line with earlier literature, these suboxide tubes show a drastically improved photoelectrochemical water‐splitting performance compared to non‐reduced anatase TiO 2 tubes. In this work we show that the key improvement in water‐splitting performance is due to the strongly improved conductivity of TiO x semimetalic tubes, reaching 13.5 KΩ per tube compared to 70 MΩ (for non‐reduced anatase), and is not due to the enhanced visible‐light absorbance.