Photocatalytic transformation of organic compounds in the presence of inorganic ions

The influence of halide ions on the photocatalytic process on titanium dioxide has been investigated carefully. Chloride and bromide ions, acting as hole scavengers, generate active radical species (e.g., ·Cl and ·Br) that participate in reactions with the organic compounds and the transient intermediates. Chloride and bromide ions have shown to deeply inhibit the degradation rate of chloroform and tetrachloromethane and to modify both the qualitative and quantitative distribution of their intermediates formed during the degradation process. In the presence of bromide, CBrCl3 is detected as intermediate during CCl4 degradation, while in the presence of chloride, formation of CCl4 is observed in the CHCl3 degradation. Fluoride ions, differently from the other halides, cannot be oxidized by the valence hole and may be used as a diagnostic tool in mechanistic studies. The influence of fluoride on phenol has been investigated, and, by choosing appropriate experimental conditions, it was possible to evaluate the role of the different active species in the photocatalytic process.

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AgCl-ZnAl Layered Double Hydroxides as Catalysts with Enhanced Photodegradation and Antibacterial Activities

Inorganics ◽

10.3390/inorganics7100120 ◽

2019 ◽

Vol 7 (10) ◽

pp. 120 ◽

Cited By ~ 4

Author(s):

Morena Nocchetti ◽

Monica Pica ◽

Berardo Ridolfi ◽

Anna Donnadio ◽

Elisa Boccalon ◽

...

Keyword(s):

Layered Double Hydroxides ◽

Degradation Process ◽

Antibacterial Activities ◽

Positive Control ◽

Active Species ◽

Interlayer Region ◽

Surface Modified ◽

Double Hydroxides ◽

Crystalline Domains

Surface-modified ZnAl layered double hydroxides (LDHs) were prepared by reaction of AgNO3, with both ZnAlCl (LDH1) and ZnAlCO3 exchanged on the surface with chloride anions (LDH3). In this way, AgCl nanoparticles with crystalline domains ranging from 40 to 100 nm were grown on the LDH surface. An additional sample was prepared by partial reduction of silver to obtain Ag@AgCl-LDH (LDH2). The composites were tested as catalysts in Rhodamine B (RhB) degradation, wherein LDH2 showed complete cleavage of RhB after 45 min of irradiation versus 70 min needed in the presence of AgCl. This time decreased to 35 min for LDH1 and 15 min for LDH3, underlining the role of the AgCl dimensions and anion in the interlayer region. Studies on the reactive species involved in the degradation process revealed that, for all catalysts, O2·− was the main active species, while, to some extent, holes contribute to the activity of the LDH3. Finally, the composites showed high bactericidal activity, under irradiation, against Escherichia coli, comparable with that of Gentamicin, the positive control. A synergic effect of silver released from the composites and the production of reactive oxygen species was considered.

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Synthetic BiOBr/Bi2S3/CdS Crystalline Material and Its Degradation of Dye under Visible Light

Crystals ◽

10.3390/cryst11080899 ◽

2021 ◽

Vol 11 (8) ◽

pp. 899

Author(s):

Yunhan Jin ◽

Zhe Xing ◽

Yinhui Li ◽

Jian Han ◽

Heike Lorenz ◽

...

Keyword(s):

Composite Material ◽

Visible Light ◽

Dye Degradation ◽

Degradation Process ◽

Active Species ◽

Order Kinetic ◽

Test Results ◽

Order Kinetic Model ◽

Epr Test

Constructing heterojunction has attracted widespread concerns in photocatalysis research. BiOBr/Bi2S3/CdS composite material with a sea urchin shape was directly obtained by first synthesizing BiOBr microspheres. The morphology, structure and composition of the composite material were characterized by XRD, EDX, SEM and XPS. Dye degradation experiments showed that 83.3% of methylene blue removal was achieved after 2 h of visible light irradiation. The reaction rate under optimal conditions was 0.014 min−1 and the photocatalytic degradation process follows a pseudo-first-order kinetic model. Based on the EPR test results, the main active species involved in the reaction were •O2− and h+. The conduction band and valence band edge potential calculations confirmed the key role of CdS in the production of •O2−.

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Site of Lysosome Production During Hepatic Injury

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100063652 ◽

1969 ◽

Vol 27 ◽

pp. 348-349

Author(s):

Nalin J. Unakar

Keyword(s):

Electron Microscopy ◽

Golgi Apparatus ◽

Mouse Liver ◽

Hepatic Injury ◽

Close Approximation ◽

Experimental Conditions ◽

Toxic Injury

The increased number of lysosomes as well as the close approximation of lysosomes to the Golgi apparatus in tissue under variety of experimental conditions is commonly observed. These observations suggest Golgi involvement in lysosomal production. The role of the Golgi apparatus in the production of lysosomes in mouse liver was studied by electron microscopy of liver following toxic injury by CCI4.

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The Affiliative Role of Empathy in Everyday Interpersonal Interactions

10.31234/osf.io/whc43 ◽

2019 ◽

Author(s):

Whitney R. Ringwald ◽

Aidan G.C. Wright

Keyword(s):

Individual Differences ◽

Structural Equation ◽

Community Sample ◽

Empirical Support ◽

Interpersonal Behavior ◽

Equation Modeling ◽

Experimental Conditions ◽

Student Sample ◽

Ecological Momentary

Empathy theoretically serves an affiliative interpersonal function by satisfying motives for intimacy and union with others. Accordingly, empathy is expected to vary depending on the situation. Inconsistent empirical support for empathy’s affiliative role may be due to methodology focused on individual differences in empathy or differences between controlled experimental conditions, which fail to capture its dynamic and interpersonal nature. To address these shortcomings, we used ecological momentary assessment to establish typical patterns of empathy across everyday interactions. Associations among empathy, affect, and interpersonal behavior of self and interaction partner were examined in a student sample (N=330), then replicated in a pre-registered community sample (N=279). Multi-level structural equation modeling was used to distinguish individual differences in empathy from interaction-level effects. Results show people are more empathetic during positively-valanced interactions with others perceived as warm and when expressing warmth. By confirming the typically affiliative role of empathy, existing research to the contrary can be best understood as exceptions to the norm.

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Sewage sludge as a precursor of adsorbents/catalysts for environmental applications

Water Practice & Technology ◽

10.2166/wpt.2007.019 ◽

2007 ◽

Vol 2 (1) ◽

Author(s):

A. Ros ◽

C. Canals-Batlle ◽

M.A. Lillo-Ródenas ◽

E. Fuente ◽

M. A. Montes-Morán ◽

...

Keyword(s):

Sewage Sludge ◽

Room Temperature ◽

Waste Water Treatment ◽

Textural Properties ◽

Active Species ◽

Elemental Sulphur ◽

Gaseous Emissions ◽

Removal Experiments ◽

Catalytically Active

This paper focuses on the valorisation of solid residues obtained from the thermal treatment of sewage sludge. In particular, sewage sludge samples were collected from two waste water treatment plants (WWTPs) with different sludge line basic operations. After drying, sludges were heated up to 700 °C in appropriate ovens under diluted air (gasification) and inert (pyrolysis) atmospheres. The solids obtained, as well as the dried (raw) sludges, were characterised to determine their textural properties and chemical composition, including the speciation of their inorganic fraction. All the materials under study were employed as adsorbents/catalysts in H2S removal experiments at room temperature. It was found that, depending on the particular sludge characteristics, outstanding results can be achieved both in terms of retention capacities and selectivity. Some of the solids outperform commercially available sorbents specially designed for gaseous emissions control. In these adsorbents/catalysts, H2S is selectively oxidised to elemental sulphur most likely due to the presence of inorganic, catalytically active species. The role of the carbon-enriched part on these solids is also remarked.

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Aging of atmospheric aerosols and the role of iron in catalyzing brown carbon formation

Environmental Science: Atmospheres ◽

10.1039/d1ea00038a ◽

2021 ◽

Author(s):

Hind A. A. Al-Abadleh

Keyword(s):

Volatile Organic Compounds ◽

Organic Compounds ◽

Atmospheric Aerosols ◽

Secondary Organic Aerosol ◽

Organic Aerosol ◽

Atmospheric Oxidation ◽

Carbon Formation ◽

Brown Carbon ◽

Volatile Organic

Extensive research has been done on the processes that lead to the formation of secondary organic aerosol (SOA) including atmospheric oxidation of volatile organic compounds (VOCs) from biogenic and anthropogenic...

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Conversion of Methanol on Rutile TiO2 (110) and Tungsten Oxide Clusters: 2. The Role of Defects and Electron Transfer in Bifunctional Oxidic Photocatalysts

Physical Chemistry Chemical Physics ◽

10.1039/d1cp01176f ◽

2021 ◽

Author(s):

Lars Mohrhusen ◽

Jessica Kräuter ◽

Katharina Al-Shamery

Keyword(s):

Electron Transfer ◽

Transition Metal ◽

Metal Oxide ◽

Tungsten Oxide ◽

Organic Compounds ◽

Uv Irradiation ◽

Organic P ◽

Rutile Tio2 ◽

Metal Oxide Surfaces

The photochemical conversion of organic compounds on tailored transition metal oxide surfaces by (UV) irradiation has found wide applications ranging from the production of chemicals to the degradation of organic...

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The Role of the Reactive Species Involved in the Photocatalytic Degradation of HDPE Microplastics Using C,N-TiO2 Powders

Polymers ◽

10.3390/polym13070999 ◽

2021 ◽

Vol 13 (7) ◽

pp. 999 ◽

Cited By ~ 1

Author(s):

Aranza Denisse Vital-Grappin ◽

Maria Camila Ariza-Tarazona ◽

Valeria Montserrat Luna-Hernández ◽

Juan Francisco Villarreal-Chiu ◽

Juan Manuel Hernández-López ◽

...

Keyword(s):

Wastewater Treatment Plants ◽

Reaction System ◽

Terrestrial Ecosystems ◽

Degradation Process ◽

Reactive Species ◽

Hazardous Substances ◽

Wide Range ◽

Degradation Behaviors ◽

Environmentally Friendly Process

Microplastics (MPs) are distributed in a wide range of aquatic and terrestrial ecosystems throughout the planet. They are known to adsorb hazardous substances and can transfer them across the trophic web. To eliminate MPs pollution in an environmentally friendly process, we propose using a photocatalytic process that can easily be implemented in wastewater treatment plants (WWTPs). As photocatalysis involves the formation of reactive species such as holes (h+), electrons (e−), hydroxyl (OH●), and superoxide ion (O2●−) radicals, it is imperative to determine the role of those species in the degradation process to design an effective photocatalytic system. However, for MPs, this information is limited in the literature. Therefore, we present such reactive species’ role in the degradation of high-density polyethylene (HDPE) MPs using C,N-TiO2. Tert-butanol, isopropyl alcohol (IPA), Tiron, and Cu(NO3)2 were confirmed as adequate OH●, h+, O2●− and e− scavengers. These results revealed for the first time that the formation of free OH● through the pathways involving the photogenerated e− plays an essential role in the MPs’ degradation. Furthermore, the degradation behaviors observed when h+ and O2●− were removed from the reaction system suggest that these species can also perform the initiating step of degradation.

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Comparative investigation of lasing and amplification performance in cryogenic Yb:YLF systems

Applied Physics B ◽

10.1007/s00340-021-07588-8 ◽

2021 ◽

Vol 127 (3) ◽

Author(s):

Umit Demirbas ◽

Martin Kellert ◽

Jelto Thesinga ◽

Yi Hua ◽

Simon Reuter ◽

...

Keyword(s):

Continuous Wave ◽

Estimation Method ◽

Laser Cavity ◽

Comparative Investigation ◽

Limiting Factor ◽

Experimental Conditions ◽

Temperature Estimation ◽

Transverse Temperature ◽

First Time

AbstractWe present detailed experimental results with cryogenic Yb:YLF gain media in rod-geometry. We have comparatively investigated continuous-wave (cw) lasing and regenerative amplification performance under different experimental conditions. In the cw lasing experiments effect of crystal doping, cw laser cavity geometry and pump wavelength on lasing performance were explored. Regenerative amplification behavior was analyzed and the role of depolarization losses on performance was investigated. A recently developed temperature estimation method was also employed for the first time in estimating average crystal temperature under lasing conditions. It is shown that the thermal lens induced by transverse temperature gradients is the main limiting factor and strategies for future improvements are discussed. To the best of our knowledge, the achieved results in this study (375 W in cw, and 90 W in regenerative amplification) are the highest average powers ever obtained from this system via employing the broadband E//a axis.

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