10.1021/acs.jpclett.5b02219.s001
Manjula
I. Nandasiri
Manjula
I.
Nandasiri
Vaithiyalingam Shutthanandan
Vaithiyalingam
Shutthanandan
Sandeep Manandhar
Sandeep
Manandhar
Ashleigh M. Schwarz
Ashleigh M.
Schwarz
Lucas Oxenford
Lucas
Oxenford
John V. Kennedy
John V.
Kennedy
Suntharampillai Thevuthasan
Suntharampillai
Thevuthasan
Michael A. Henderson
Michael A.
Henderson
Instability of Hydrogenated TiO<sub>2</sub>
American Chemical Society
2015
bulk diffusivity
Hydrogenated TiO 2Hydrogenated TiO 2
Similar anneals
photoelectron spectroscopy
nm
473 K
373 K
reaction analysis
rutile
light photocatalyst
surface
523 K
NRA
2015-11-11 05:03:17
Journal contribution
https://acs.figshare.com/articles/journal_contribution/Instability_of_Hydrogenated_TiO_sub_2_sub_/2005401
Hydrogenated
TiO<sub>2</sub> (H-TiO<sub>2</sub>) is touted as a
viable visible light photocatalyst. We report a systematic study on
the thermal stability of H-implanted TiO<sub>2</sub> using nuclear
reaction analysis (NRA), Rutherford backscattering spectrometry, ultraviolet
photoelectron spectroscopy, and X-ray photoelectron spectroscopy.
Protons (40 keV) implanted at a ∼2 atom % level within a ∼120
nm wide profile of rutile TiO<sub>2</sub>(110) were situated ∼300
nm below the surface. NRA revealed that this H-profile broadened toward
the surface after annealing at 373 K, dissipated out of the crystal
into vacuum at 473 K, and was absent within the beam sampling depth
(∼800 nm) at 523 K. Photoemission showed that the surface was
reduced in concert with these changes. Similar anneals had no effect
on pristine TiO<sub>2</sub>(110). The facile bulk diffusivity of H
in rutile at low temperatures, as well as its interfacial activity
toward reduction, significantly limits the utilization of H-TiO<sub>2</sub> as a photocatalyst.