Defect-triggered catalysis with multiple reactive species over bismuth oxyhalides in the dark

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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Relevance of mitochondrial dysfunction during Sorafenib-induced cell death in liver cancer cells. Role of oxidative and nitrogen reactive species

Free Radical Biology and Medicine ◽

10.1016/j.freeradbiomed.2020.12.418 ◽

2021 ◽

Vol 165 ◽

pp. 54

Author(s):

Patricia de la Cruz-Ojeda ◽

M. Ángeles Rodríguez-Hernández ◽

Elena Navarro-Villarán ◽

Paloma Gallego ◽

Pavla Staňková ◽

...

Keyword(s):

Cell Death ◽

Liver Cancer ◽

Mitochondrial Dysfunction ◽

Cancer Cells ◽

Reactive Species ◽

Liver Cancer Cells ◽

Nitrogen Reactive Species

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Bismuth Oxyhalides for NOx Degradation under Visible Light: The Role of the Chloride Precursor

Catalysts ◽

10.3390/catal11010081 ◽

2021 ◽

Vol 11 (1) ◽

pp. 81

Author(s):

Francesca Tessore ◽

Federico Galli ◽

Dalma Schieppati ◽

Daria C. Boffito ◽

Alessandro Di Michele ◽

...

Keyword(s):

Photocatalytic Activity ◽

Visible Light ◽

Photogenerated Electron ◽

Green Technology ◽

Bandgap Energy ◽

Visible Radiation ◽

Bismuth Nanoparticles ◽

Metallic Bismuth ◽

Bismuth Oxyhalides ◽

The Impact

Photocatalysis is a green technology for tackling water and air contamination. A valid alternative to the most exploited photocatalytic material, TiO2, is bismuth oxyhalides, which feature a wider bandgap energy range and use visible radiation to attain photoexcitation. Moreover, their layered structure favors the separation of photogenerated electron–hole pairs, with an enhancement in photocatalytic activity. Controlled doping of bismuth oxyhalides with metallic bismuth nanoparticles allows for further boosting of the performance of the material. In the present work, we synthesized Y%Bi-doped BiO(Cl0.875Br0.125) (Y = 0.85, 1, 2, 10) photocatalysts, using cetyltrimethylammonium bromide as the bromide source and varying the chloride source to assess the impact that both length and branching of the hydrocarbon chain might have on the framing and layering of the material. A change in the amount of the reducing agent NaBH4 allowed tuning of the percentage of metallic bismuth. After a thorough characterization (XRPD, SEM, TEM, UV-DRS, XPS), the photocatalytic activity of the catalysts was tested in the degradation of NOx under visible light, reaching a remarkable 53% conversion after 3 h of illumination for the material prepared using cetylpyridinium chloride.

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Non-thermal pulsed plasma activated water: environmentally friendly way for efficient surface modification of semiconductor nanoparticles

Green Chemistry ◽

10.1039/d0gc02619k ◽

2021 ◽

Author(s):

Pavel Galář ◽

Josef Khun ◽

Anna Fučíková ◽

Kateřina Dohnalová ◽

Tomáš Popelář ◽

...

Keyword(s):

Surface Modification ◽

Free Surface ◽

Thermal Plasma ◽

Environmentally Friendly ◽

Semiconductor Nanoparticles ◽

Reactive Species ◽

Pulsed Plasma ◽

Non Thermal Plasma ◽

Plasma Activated Water

Non-thermal plasma activated water can be used for cheap, easy and chemicals-free surface modification of nanoparticles, with all the reactive species originating solely in air and water.

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Ketoprofen degradation by surface reactive species on TiO2, AgxOy/MoxOy/catalysts

Materials Letters ◽

10.1016/j.matlet.2021.129687 ◽

2021 ◽

pp. 129687

Author(s):

Andrés Suárez-Escobar ◽

Vicente Rodríguez-González ◽

Carlos Gallardo-Vega ◽

Edwin Sarria ◽

Lorena Clavijo

Keyword(s):

Reactive Species

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Structire, Properties, and Process Characteristics of Low-K Materials Prepared by PECVD

MRS Proceedings ◽

10.1557/proc-565-255 ◽

1999 ◽

Vol 565 ◽

Author(s):

Y. Shimogaki ◽

S. W. Lim ◽

E. G. Loh ◽

Y. Nakano ◽

K. Tada ◽

...

Keyword(s):

Growth Rate ◽

Dielectric Constant ◽

Gas Flow ◽

Structural Changes ◽

Silicon Oxide ◽

Reactive Species ◽

Low Dielectric Constant ◽

Low Dielectric ◽

Step Coverage ◽

Low K

AbstractLow dielectric constant F-doped silicon oxide films (SiO:F) can be prepared by adding fluorine source, like as CF4 to the conventional PECVD processes. We could obtain SiO:F films with dielectric constant as low as 2.6 from the reaction mixture of SiH4/N2 O/CF4. The structural changes of the oxides were sensitively detected by Raman spectroscopy. The three-fold ring and network structure of the silicon oxides were selectively decreased by adding fluorine into the film. These structural changes contribute to the decrease ionic polarization of the film, but it was not the major factor for the low dielectric constant. The addition of fluorine was very effective to eliminate the Si-OH in the film and the disappearance of the Si-OH was the key factor to obtain low dielectric constant. A kinetic analysis of the process was also performed to investigate the reaction mechanism. We focused on the effect of gas flow rate, i.e. the residence time of the precursors in the reactor, on growth rate and step coverage of SiO:F films. It revealed that there exists two species to form SiO:F films. One is the reactive species which contributes to increase the growth rate and the other one is the less reactive species which contributes to have uniform step coverage. The same approach was made on the PECVD process to produce low-k C:F films from C2F4, and we found ionic species is the main precursor to form C:F films.

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