Кафедра биофизики

  • Increase font size
  • Default font size
  • Decrease font size
Главная страница Новости науки Journal of Photochemistry and Photobiology A: Chemistry
Новости науки
ScienceDirect Publication: Journal of Photochemistry and Photobiology A: Chemistry
ScienceDirect RSS

  • Influence of preparation method and nitrogen (N) doping on properties and photo-catalytic activity of mesoporous SrTiO3

    Publication date: 1 January 2019

    Source: Journal of Photochemistry and Photobiology A: Chemistry, Volume 368

    Author(s): I. Atkinson, V. Parvulescu, J. Pandele Cusu, E.M. Anghel, M. Voicescu, D. Culita, S. Somacescu, C. Munteanu, M. Šćepanović, Z.V. Popovic, V. Fruth

    Abstract

    Nitrogen (N)-doped SrTiO3 /pristine SrTiO3 powders were synthesized by three different methods namely hydrothermal, sol-gel route and solid state reaction respectively. The influence of synthesis route, thermal treatment atmosphere and N doping on the properties and photo-catalytic efficiency of the prepared samples was analyzed. The investigation shows that N doping causes the narrowing of the band gap with about 1 eV. The synergy of the structure, texture and morphology and especially N doping explains high methyl orange (MO) degradation efficiency of 100% within 1 h of irradiation for the N doped SrTiO3 obtained by sol-gel route with the aid of non-ionic triblock copolymer (Pluronic P123) as a structure-directing and thermally treated under nitrogen atmosphere.

    Graphical abstract

    Graphical abstract for this article



  • Enhancement of efficiency of natural and organic dye sensitized solar cells using thin film TiO2 photoanodes fabricated by spin-coating

    Publication date: 1 January 2019

    Source: Journal of Photochemistry and Photobiology A: Chemistry, Volume 368

    Author(s): Z.K. Yildiz, A. Atilgan, A. Atli, K. Özel, C. Altinkaya, A. Yildiz

    Abstract

    To fabricate dye-sensitized solar cells (DSSCs), TiO2 thin films with different cycles of coating were deposited on FTO-coated glass substrates by the spin coating method. Black mulberry (Morus Nigra), madder (Rubia Tinctorum) roots, and eosin-y (C20H8Br4O5) were used as sensitizers. The photovoltaic conversion performance parameters of the devices were obtained under illumination of simulated AM1.5 solar light (100 mW cm−2). By using a photoanode prepared after 15 cycles of coating, the best power conversion efficiency of 1.3% was attained with the devices loaded with black mulberry.

    Graphical abstract

    Graphical abstract for this article



  • Ink-jet printing films of molybdates of alkaline earth metals with scheelite structure applied in the photocatalytic CO2 reduction

    Publication date: 1 January 2019

    Source: Journal of Photochemistry and Photobiology A: Chemistry, Volume 368

    Author(s): E. Luévano-Hipólito, Leticia M. Torres-Martínez

    Abstract

    The photocatalytic CO2 reduction is a clean and sustainable process to generate value-added products by using water, sunlight, and photocatalysts materials. In this work, it is proposed the use of thin films based on molybdates of alkaline earth metals of general formula AMoO4 (A = Ca, Sr, and Ba) with scheelite-structure as photocatalysts for the conversion of CO2. The films were deposited by ink-jet printing, which is a technique that offers high speed and low cost of fabrication, and provide the possibility to print over different substrates. The AMoO4 films were characterized by razing incidence X-ray diffraction (GZXD), Fourier-transform Infrared Spectroscopy (FTIR), Scanning Electronic Microscopy (SEM), Diffuse Reflectance Spectroscopy (DRS), profilometry, spectroscopic ellipsometry (SE), Electrochemical Impedance Spectroscopy (EIS), and zeta potential measurements. According to the characterization, it was confirmed the crystallization of the scheelite structure in the CaMoO4, SrMoO4, and BaMoO4 films. The effect of the type and size of the A cation affected several physical properties such as crystallite size, thickness, potential of the conduction band, zeta potential, and the affinity for CO2 adsorption, which it was reflected in the photocatalytic activity of each film. The main product of the photocatalytic CO2 reduction was CH3OH, although it was detected the formation of H2 as by-product of the reaction. The photocatalytic activity for methanol production increased as follows: CaMoO4>SrMoO4>BaMoO4, which it was related to a higher affinity for CO2 molecule, low crystallite size, low thickness, adequate potential of conduction band and a higher donor number. The highest solar fuel yield obtained was 18 μmol cm−2 h−1, which it was higher than previous reports using films of other semiconductor materials.

    Graphical abstract

    Graphical abstract for this article



  • A composite microfibre-supported short-nanofibre photocatalyst for environmental pollutant decomposition

    Publication date: 1 January 2019

    Source: Journal of Photochemistry and Photobiology A: Chemistry, Volume 368

    Author(s): Ruta Sidaraviciute, Dalia Buivydiene, Edvinas Krugly, Eugenijus Valatka, Dainius Martuzevicius

    Abstract

    Titanium dioxide in different forms such as films, fibres or particles are being extensively studied due to its excellent photocatalytic activity for decomposition of variety organic pollutants. 1-D structured fibrous TiO2 is getting more attention as an attractive candidate for practical applications due to its morphological advantages. This paper describes the production and characterization of supported TiO2 nanofibrous layers, produced by electrospinning process on different supports. A photocatalytic active anatase phase within fibres was obtained, with relatively high specific surface are of 83.9 m2/g. A novel organic–inorganic hybrid catalyst with rough and branchy structure is reported. The photocatalytic performance of the processed samples was measured by following the degradation of organic pollutants in aqueous and air media. The notable photocatalytic activity shows that the composite samples can be competitive catalyst media based on structural properties and the degradation efficiency of several organic pollutants.

    Graphical abstract

    Graphical abstract for this article



  • Heterogeneous photodegradation of Pyrimethanil and its commercial formulation with TiO2 immobilized on SiC foams

    Publication date: 1 January 2019

    Source: Journal of Photochemistry and Photobiology A: Chemistry, Volume 368

    Author(s): Ignace Christian M’Bra, Patricia García-Muñoz, Patrick Drogui, Nicolas Keller, Albert Trokourey, Didier Robert

    Abstract

    Vine is one of the crops undergoing the most pesticide treatment. Due to the presence of pesticides residues in water and food, and the negative effects on human and wildlife health, it is necessary to develop an effective treatment. Photocatalytic oxidation using semiconductors is one of the advanced oxidation processes for degradation of organic pollutants in water and air. A TiO2 in nanopowder is an excellent photocatalyst that can mineralize a large range of organic pollutants such as pesticides and dyes. In order to eliminate the problems due to TiO2 nanoparticles, we have successfully supported TiO2 on β-SiC foams. The supporting material has been used to degrade Pyrimethanil molecule and its commercial formulation: Scala® a fungicide produced by BASF Company. After 4 h of treatment in our conditions, a 88% and 74% of Pyrimethanil and Scala was removed with a 58 and 47% of mineralization, respectively. These results are very encouraging because there is no need to filter to separate the catalyst from the treated water which is very important for a large-scale use of this process.

    Graphical abstract

    Graphical abstract for this article



  • Novel Z-scheme composite Ag2CrO4/NG/polyimide as high performance nano catalyst for photoreduction of CO2: Design, fabrication, characterization and mechanism

    Publication date: 1 January 2019

    Source: Journal of Photochemistry and Photobiology A: Chemistry, Volume 368

    Author(s): Liang Zhou, Hesam Kamyab, Aravindhan Surendar, Andino Maseleno, Aygul Z. Ibatova, Shreeshivadasan Chelliapan, Nima Karachi, Zohreh Parsaee

    Abstract

    The evolution of new Z-scheme composites aids to solve the increasing energy demand via artificial photosynthesis. This research introduced novel Z-scheme nanocomposite, Ag2CrO4/nitrogen-doped graphene /Polyimide (Ag2CrO4/NG/PI), and its photocatalytic activity in CO2 reduction under simulated sunlight irradiation. The nanocomposite was prepared with ultrasound-assisted in-situ deposition of different amounts of Ag2CrO4-NPs on NG/ PI and completely characterized using various techniques such as AFM, FE-SEM, XPS, XRD, FT-IR, DRS and PL which confirmed the presence of Ag2CrO4, NG and PI in the composite structure. The photocatalytic investigations showed a significant promotion for light absorption ability of Ag2CrO4 on NG and PI. The high performance photocatalytic activity of Ag2CrO4/NG/PI can be interpreted by the gap of EHPs in the photocatalyst as a Z-scheme due to the construction of hetero-linkage structure between Ag2CrO4 and PI. Meanwhile, the presence of the pyridinic N as an unique selective site toward CO generation, can reduce the free energy barrier for the potential-limiting step to compose important intermediates which lead to high-efficiency photocatalyst activity. The optimal Ag2CrO4/NG/PI (25AN) photocatalyst presented a CO2 photoreduction rate of 352.1 μmol h−1·gcat −1, which was higher than previously reported works under similar condition. This investigation introduces a novel photocatalyst nanocomposite of the, Ag2CrO4/NG/PI, in concurrent natural resources conservation and green productivity.

    Graphical abstract

    Graphical abstract for this article



  • Clearing up the photochemistry of resveratrol: Effect of the solvent

    Publication date: 1 December 2018

    Source: Journal of Photochemistry and Photobiology A: Chemistry, Volume 367

    Author(s): Maira Gaspar Tosato, Patricia Vicendo, Andrés H. Thomas, Carolina Lorente

    Abstract

    Polyphenolic substances synthesized by plants are generally involved in protection against UV radiation and the attack of pathogenic microorganisms. Resveratrol (3,5,4′-trihydroxystilbene, RSV) is synthesized in its trans-form (trans-RSV) in plants under stress conditions like infections or UV exposure and has attracted attention as an antioxidant agent. Trans-RSV was irradiated with both UV-A (λMAX = 365 nm) and UV-B (λMAX = 300 nm) radiation in aqueous and ethanolic solutions at room temperature. The reactions were followed by UV–Vis spectrophotometry, HPLC with UV and fluorescence detection, and UPLC coupled to mass spectrometry detection. In both solvents the irradiation caused the fast isomerization of trans-RSV to cis-RSV. In ethanolic solutions, a strong fluorescent compound, identified as resveratrone (RSVT) was detected independently on the irradiation wavelength. In aqueous solutions, RSVT was not detected in both irradiation conditions. However, in aqueous/ethanol mixtures the amount RSVT was found to be proportional to the amount of ethanol in the solution. Under UV-B irradiation, both in ethanolic or water solutions other products were detected. Our results demonstrated that RSV is photosensitive and its photochemistry depends on the solvent nature and on the irradiation wavelength.

    Graphical abstract

    Graphical abstract for this article



  • Synthesis and properties of new UVA-sensitive photoacid generators of super acid for near-UV LED applications

    Publication date: 1 December 2018

    Source: Journal of Photochemistry and Photobiology A: Chemistry, Volume 367

    Author(s): Lijiang Huang, Huanyan Liao, Jianwen Yang, Zhaohua Zeng

    Abstract

    Thioxanthone sulfonate photoacid generators (PAGs) for super acid sensitive to UVA were synthesized using thioxanthone derivatives with perfluoroalkyl sulfonate units with good thermal stability (over 240℃). The PAGs exhibited good photoreactivity with photoacid generation quantum yields (Φa) between 0.10 to 0.14, and well utilized the energy of the UV-LED at 365, 385 and 395 nm.

    Graphical abstract

    Thioxanthone sulfonate photoacid generators (PAGs) for super acid sensitive to UV-A were synthesized using thioxanthone derivatives with perfluoroalkyl sulfonate units with good thermal stability (over 240℃). The PAGs exhibited good photoreactivity with photoacid generation quantum yields (Φa) between 0.10 to 0.14, and well utilized the energy of the UV-LED at 365, 385 and 395 nm.

    Photoacid concentration of 1a or 1b as a function of the absorbed photo dose at 365 nm or 385 nm or 395 nm.

    Graphical abstract for this article



  • A new sensitive symmetric fluorescein-linked diarylethene chemosensor for Hg2+ detection

    Publication date: 1 December 2018

    Source: Journal of Photochemistry and Photobiology A: Chemistry, Volume 367

    Author(s): Huimin Kang, Huitao Xu, Congbin Fan, Gang Liu, Shouzhi Pu

    Abstract

    A novel symmetrical diarylethene derivative bearing a fluorescein unit was synthesized and its application as a fluorescent probe for the detection of metal ions in environmental, biological, and industrial samples was explored. It displayed both highly sensitive and selective fluorescent and colorimetric responses toward Hg2+ in the binding stoichiometry of 1:1. The fluorescence intensity of the derivative was significantly enhanced in the presence of Hg2+ with the blue-shift from 550 nm to 504 nm. In addition, it exhibited multiple controllable switching behaviors under light and chemical stimulations. Based on its “OFF–ON–OFF” fluorescence switching behaviors, a combinational logic gate function was constructed using the light and chemical stimuli as the inputs and the fluorescence intensity at 504 nm as the output.

    Graphical abstract

    Graphical abstract for this article



  • Synthesis and characterization of transparent photocatalytic ZnO-Sm2O3 and ZnO-Er2O3 coatings

    Publication date: 1 December 2018

    Source: Journal of Photochemistry and Photobiology A: Chemistry, Volume 367

    Author(s): I.S. Boltenkov, E.V. Kolobkova, S.K. Evstropiev

    Abstract

    This article describes the synthesis and characterization of transparent photocatalytic ZnO-Sm2O3 and ZnO-Er2O3 coatings. Transparent coatings were prepared by the liquid polymer-salt method and were studied by the optical and luminescence spectroscopy, SEM analysis and DSC method. Prepared coatings consist of small closely packed oxide nanoparticles and demonstrate high transparency in visible spectral range, photocatalytic properties and the ability to generate singlet oxygen under UV irradiation.

    Graphical Abstract

    Graphical abstract for this article



Научная работа