Photodegradation of metoprolol in the presence of aquatic fulvic acids. Kinetic studies, degradation pathways and role of singlet oxygen, OH radicals and fulvic acids triplet states

The aim of this study was to investigate some aspects of the performance of electrochemical process as an alternative disinfection strategy, while minimising DBPs, for water purification. The study of electrochemical processes has shown free chlorine to be produced, but smaller amounts of stronger oxidants, such as ozone, hydrogen peroxide and OH radicals (•OH), were also generated. The formation of mixed oxidants increased with increasing electric conductivity, but was limited at conductivities greater than 0.6 mS/cm. Using several microorganisms, such as E. coli and MS2 bacteriophage, inactivation kinetic studies were performed. With the exception of free chlorine, the role of mixed oxidants, especially OH radicals, was investigated for enhancement of the inactivation rate. Additionally, the formation and reduction of DBPs was studied by monitoring the concentration of haloacetic acids (HAAs) during the process.

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Role Of Protochlorophyllide Oxidoreductase C In Protection Of Plants From Singlet Oxygen-Induced Oxidative Stress1

Bioscience Biotechnology Research Communications ◽

10.21786/bbrc/12.2/38 ◽

2019 ◽

Vol 12 (2) ◽

pp. 504-511

Author(s):

Garima Chauhan ◽

Baishnab C Tripathy

Keyword(s):

Singlet Oxygen ◽

Protochlorophyllide Oxidoreductase

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Role of Lys-226 in the Catalytic Mechanism ofBacillus StearothermophilusSerine HydroxymethyltransferaseCrystal Structure and Kinetic Studies†,‡

Biochemistry ◽

10.1021/bi047800x ◽

2005 ◽

Vol 44 (18) ◽

pp. 6929-6937 ◽

Cited By ~ 11

Author(s):

Siddegowda Bhavani ◽

V. Trivedi ◽

V. R. Jala ◽

H. S. Subramanya ◽

Purnima Kaul ◽

...

Keyword(s):

Catalytic Mechanism ◽

Kinetic Studies

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Role of Triplet States in the Photodynamics of Aniline

Journal of the American Chemical Society ◽

10.1021/jacs.1c00989 ◽

2021 ◽

Vol 143 (15) ◽

pp. 5878-5889

Author(s):

Aleksandr O. Lykhin ◽

Donald G. Truhlar ◽

Laura Gagliardi

Keyword(s):

Triplet States

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Kinetic studies of excited singlet oxygen atom O( 1 D) reactions with ethanol

International Journal of Chemical Kinetics ◽

10.1002/kin.21474 ◽

2021 ◽

Author(s):

Hongtao Zhong ◽

Chao Yan ◽

Chu C. Teng ◽

Timothy Y. Chen ◽

Gerard Wysocki ◽

...

Keyword(s):

Oxygen Atom ◽

Singlet Oxygen ◽

Kinetic Studies ◽

Excited Singlet

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Delivery of Electrons by Proton-Hole Transfer in Ice at 10 K: Role of Surface OH Radicals

The Journal of Physical Chemistry Letters ◽

10.1021/acs.jpclett.0c03345 ◽

2021 ◽

pp. 704-710

Author(s):

Kensei Kitajima ◽

Yoichi Nakai ◽

W. M. C. Sameera ◽

Masashi Tsuge ◽

Ayane Miyazaki ◽

...

Keyword(s):

Oh Radicals ◽

Hole Transfer

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The role of spin in the degradation of organic photovoltaics

Nature Communications ◽

10.1038/s41467-020-20601-6 ◽

2021 ◽

Vol 12 (1) ◽

Author(s):

Ivan Ramirez ◽

Alberto Privitera ◽

Safakath Karuthedath ◽

Anna Jungbluth ◽

Johannes Benduhn ◽

...

Keyword(s):

Transient Absorption ◽

Bulk Heterojunction ◽

Critical Factor ◽

Model Systems ◽

Transient Absorption Spectroscopy ◽

Triplet States ◽

Paramagnetic Resonance ◽

Time Resolved ◽

A Charge

AbstractStability is now a critical factor in the commercialization of organic photovoltaic (OPV) devices. Both extrinsic stability to oxygen and water and intrinsic stability to light and heat in inert conditions must be achieved. Triplet states are known to be problematic in both cases, leading to singlet oxygen production or fullerene dimerization. The latter is thought to proceed from unquenched singlet excitons that have undergone intersystem crossing (ISC). Instead, we show that in bulk heterojunction (BHJ) solar cells the photo-degradation of C60 via photo-oligomerization occurs primarily via back-hole transfer (BHT) from a charge-transfer state to a C60 excited triplet state. We demonstrate this to be the principal pathway from a combination of steady-state optoelectronic measurements, time-resolved electron paramagnetic resonance, and temperature-dependent transient absorption spectroscopy on model systems. BHT is a much more serious concern than ISC because it cannot be mitigated by improved exciton quenching, obtained for example by a finer BHJ morphology. As BHT is not specific to fullerenes, our results suggest that the role of electron and hole back transfer in the degradation of BHJs should also be carefully considered when designing stable OPV devices.

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