Demyanenko Alexander

Master student

Bachelor of Science in Physics

Education

Novosibirsk State University

2019 - now

Master of Science in Physics, Minor: Chemical-Biological Physics

Novosibirsk State University

2015 - 2019

Bachelor of Science in Physics, Minor: Chemical-Biological Physics

Publications

Singlet Oxygen ¹O₂ in Photocatalysis on TiO₂. Where Does It Come from?

The Journal of Physical Chemistry C

Features of the near-infrared phosphorescence of singlet oxygen ¹O₂ photosensitized by TiO₂ in solutions have been investigated. The short-lived phosphorescence of ¹O₂ with spectral maximum at approximately 1300 nm is observed to follow excitation by pulsed laser radiation at 355 nm of TiO₂ suspended in CCl₄ and water H₂O. The shorter lifetime and spectral shift of this phosphorescence, as compared with phosphorescence of ¹O₂ sensitized by phenalenone in these solvents, are attributed to the adsorbed state of emitting singlet oxygen. The observed laser pulse energy dependence indicates the two-photon and three-photon nature of this phosphorescence initiation in CCl₄ and H₂O, respectively. The formation of ¹O₂ in CCl₄ is assumed to be provided by the sequence of one-photon excitation of TiO₂, giving rise to superoxide anion O₂^– and one-photon photodetachment of electron from O₂^–. The photodetachment of electron from O₂^– in water H₂O is a two-photon process because of higher solvation energy of superoxide anion in water. The processes that govern the rise and decay of singlet oxygen phosphorescence sensitized by TiO₂ are discussed. The factors affecting the yield of singlet oxygen provided by electron photodetachment are also considered.

Reply to Comments on “Singlet Oxygen ¹O₂ in Photocatalysis on TiO₂. Where Does It Come from?”

The Journal of Physical Chemistry C

In the Comment the authors Y. Nosaka and A. Y. Nosaka present arguments against the mechanism of singlet oxygen production which was suggested in the earlier published paper (Demyanenko et al., J. Phys. Chem. C 2019, 123, 2175) to explain the experimental data for the Near IR (NIR)-luminescence observed to appear after laser excitation at 355 nm of TiO₂ suspension in air-saturated solvents CCl₄ and H₂O. The main arguments of the Comment are directed against Assignment of the NIR Emission and Electron Photodetachment Mechanism suggested by Demyanenko et al.. Particularly the Comment claims that the red shift (near 30 nm) and bandwidth (50-60 nm) of the NIR luminescence observed in paper by Demyanenko et al. are too large to be assigned to the luminescence of singlet oxygen ¹O₂. In the Reply it is shown that several arguments of the Comment are based on the incorrect statements. The current interpretation of the nature of the red shift and bandwidth of the luminescence of singlet oxygen governed by interaction with the environment is considered. It is shown that the characteristics of NIR luminescence (rather large red shift and bandwidth as compared with the literature data for the luminescence of ¹O₂ in solutions) observed in experiments by Demyanenko et al. are in a qualitative agreement with expected tendencies. All the arguments of the Comment are considered in detail and extended reply is given.

A Broadband Near-IR Detector Based on a Large-Area InGaAs Photodiode for Time-Resolved Detection of Singlet Oxygen

Instruments and Experimental Techniques

Demyanenko Alexander

Master student

Education

Novosibirsk State University

Novosibirsk State University

Publications

Singlet Oxygen 1O2 in Photocatalysis on TiO2. Where Does It Come from?

Reply to Comments on “Singlet Oxygen 1O2 in Photocatalysis on TiO2. Where Does It Come from?”

A Broadband Near-IR Detector Based on a Large-Area InGaAs Photodiode for Time-Resolved Detection of Singlet Oxygen

Singlet Oxygen ¹O₂ in Photocatalysis on TiO₂. Where Does It Come from?

Reply to Comments on “Singlet Oxygen ¹O₂ in Photocatalysis on TiO₂. Where Does It Come from?”