Photogenerated charge carriers and paramagnetic species in (W,N)-codoped TiO2 photocatalysts under visible-light irradiation: An EPR study

Folli, Andrea ORCID: https://orcid.org/0000-0001-8913-6606, Bloh, Jonathan Z., Beukes, Eva-Panduleni, Howe, Russell F. and Macphee, Donald E. 2013. Photogenerated charge carriers and paramagnetic species in (W,N)-codoped TiO2 photocatalysts under visible-light irradiation: An EPR study. Journal of Physical Chemistry C 117 (42) , p. 22149. 10.1021/jp408181r

Full text not available from this repository.

Abstract

(W,N)-codoped TiO2 has recently attracted interest due to substantial band gap narrowing in conjunction with good visible-light photocatalytic activities. A complete picture of the fundamental mechanism at the origin of their photoactivity is, however, far from being understood. We present an EPR study on (W,N)-codoped titanias by recording spectra in the dark and under 550 nm visible-light irradiation to identify the major species involved in the formation and migration of photogenerated charge carriers. Interstitial N–lattice O (formally NO2–) paramagnetic groups with and without a specific close range coupling interaction with a neighboring W, that is, [NiO]W● and [NiO]●, respectively, are observed when visible light excites electrons from diamagnetic intraband gap states located at ∼2.30 V versus RHE (formally NO3–) to the conductance band at around −0.05 V versus RHE. The [NiO]W● EPR signal, reported here for the first time, is characterized by a much stronger hyperfine interaction between the unpaired electron and the 14N nucleus than ordinary [NiO]● found in N-doped TiO2, leading to a much higher spin density on the N center. The overall signal also contains superhyperfine coupling of the unpaired electron with the 183W nuclide (natural abundance 14.31%), the only naturally occurring nuclide of W with a nonzero nuclear spin.

Item Type:	Article
Date Type:	Publication
Status:	Published
Schools:	Schools > Chemistry
Publisher:	American Chemical Society
ISSN:	1932-7447
Last Modified:	07 Nov 2022 09:24
URI:	https://orca.cardiff.ac.uk/id/eprint/129036

Citation Data

Cited 20 times in Scopus. View in Scopus. Powered By Scopus® Data

Actions (repository staff only)

Edit Item