%0 Journal Article
%A Nandasiri, Manjula
I.
%A Shutthanandan, Vaithiyalingam
%A Manandhar, Sandeep
%A Schwarz, Ashleigh M.
%A Oxenford, Lucas
%A Kennedy, John V.
%A Thevuthasan, Suntharampillai
%A Henderson, Michael A.
%D 2015
%T Instability of Hydrogenated TiO2
%U https://acs.figshare.com/articles/journal_contribution/Instability_of_Hydrogenated_TiO_sub_2_sub_/2005401
%R 10.1021/acs.jpclett.5b02219.s001
%2 https://acs.figshare.com/ndownloader/files/3011961
%K bulk diffusivity
%K Hydrogenated TiO 2Hydrogenated TiO 2
%K Similar anneals
%K photoelectron spectroscopy
%K nm
%K 473 K
%K 373 K
%K reaction analysis
%K rutile
%K light photocatalyst
%K surface
%K 523 K
%K NRA
%X Hydrogenated
TiO2 (H-TiO2) is touted as a
viable visible light photocatalyst. We report a systematic study on
the thermal stability of H-implanted TiO2 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 TiO2(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 TiO2(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-TiO2 as a photocatalyst.
%I ACS Publications