TY - JOUR

T1 - Origin of Near-Infrared Luminescence Provided by UV-Photoexcitation of TiO 2 -Based and Non-TiO 2 -Based Photocatalysts: Experiment and Theory

AU - Ershov, Kirill S.

AU - Bogomolov, Alexandr S.

AU - Demyanenko, Alexander V.

AU - Yanshin, Alexei O.

AU - Dozmorov, Nikolay V.

AU - Bogdanchikov, Georgii A.

AU - Baklanov, Alexey V.

N1 - Authors acknowledge the core funding from the Russian Federal Ministry of Science and Higher Education (FWGF-2021-0005). Публикация для корректировки.

PY - 2023/10/26

Y1 - 2023/10/26

N2 - The origin of near-infrared (NIR, 1100-1700 nm) luminescence appearing after UV-excitation (355 nm) of TiO2 (P25, rutile, anatase), ZnO, and WO3 photocatalysts is investigated experimentally and with ab initio complete active space (CAS) calculations. UV-excitation of all photocatalysts gives rise to NIR luminescence with very similar spectra. The strong effect of the elevated pressure of oxygen on the rate of burning-out of the precursor of NIR luminescence indicates that adsorbed oxygen is this precursor. Observed spectra contain a “narrow” band at 1300 nm and a red-shifted “broad” band with a maximum at 1600-1620 nm, both of which are assigned to adsorbed singlet oxygen O2(1Δg). CAS calculations for the van der Waals complex of TiO2 with singlet oxygen O2, as a system modeling O2 adsorbed on TiO2, show splitting of the 1Δg state into open-shell (OSS) and closed-shell (CSS) singlet substates. The observed “narrow” band at 1300 nm is assigned to the luminescence of the OSS substate (0,0) and the red-shifted “broad” band is assigned to contributions of the OSS band (0,1) and luminescence of the CSS substate. Both bands of singlet oxygen are superimposed on the descending background luminescence, which is assigned to be provided by a long-wavelength tail of the luminescence of superoxide anion O2- bound with the matrix of the photocatalyst.

AB - The origin of near-infrared (NIR, 1100-1700 nm) luminescence appearing after UV-excitation (355 nm) of TiO2 (P25, rutile, anatase), ZnO, and WO3 photocatalysts is investigated experimentally and with ab initio complete active space (CAS) calculations. UV-excitation of all photocatalysts gives rise to NIR luminescence with very similar spectra. The strong effect of the elevated pressure of oxygen on the rate of burning-out of the precursor of NIR luminescence indicates that adsorbed oxygen is this precursor. Observed spectra contain a “narrow” band at 1300 nm and a red-shifted “broad” band with a maximum at 1600-1620 nm, both of which are assigned to adsorbed singlet oxygen O2(1Δg). CAS calculations for the van der Waals complex of TiO2 with singlet oxygen O2, as a system modeling O2 adsorbed on TiO2, show splitting of the 1Δg state into open-shell (OSS) and closed-shell (CSS) singlet substates. The observed “narrow” band at 1300 nm is assigned to the luminescence of the OSS substate (0,0) and the red-shifted “broad” band is assigned to contributions of the OSS band (0,1) and luminescence of the CSS substate. Both bands of singlet oxygen are superimposed on the descending background luminescence, which is assigned to be provided by a long-wavelength tail of the luminescence of superoxide anion O2- bound with the matrix of the photocatalyst.

UR - https://www.scopus.com/record/display.uri?eid=2-s2.0-85177235781&origin=inward&txGid=3014de1c6b8a732c5b8a85e53317e34b

UR - https://www.mendeley.com/catalogue/33281ed1-683d-3f61-b535-be94955e19fb/

U2 - 10.1021/acs.jpcc.3c04919

DO - 10.1021/acs.jpcc.3c04919

M3 - Article

VL - 127

SP - 20762

EP - 20770

JO - Journal of Physical Chemistry C

JF - Journal of Physical Chemistry C

SN - 1932-7447

IS - 42

ER -