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Bárdos E, Márta VA, Fodor S, Kedves EZ, Hernadi K, Pap Z. Hydrothermal Crystallization of Bismuth Oxychlorides (BiOCl) Using Different Shape Control Reagents. MATERIALS 2021; 14:ma14092261. [PMID: 33925623 PMCID: PMC8123882 DOI: 10.3390/ma14092261] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 03/03/2021] [Revised: 04/06/2021] [Accepted: 04/21/2021] [Indexed: 11/24/2022]
Abstract
Bismuth oxychloride photocatalysts were obtained using solvothermal synthesis and different additives (CTAB—cetyltrimethylammonium bromide, CTAC—cetyltrimethylammonium chloride, PVP–polyvinylpyrrolidone, SDS–sodium dodecylsulphate, U—urea and TU—thiourea). The effect of the previously mentioned compounds was analyzed applying structural (primary crystallite size, crystal phase composition, etc.), morphological (particle geometry), optical (band gap energy) parameters, surface related properties (surface atoms’ oxidation states), and the resulted photocatalytic activity. A strong dependency was found between the surface tension of the synthesis solutions and the overall morpho-structural parameters. The main finding was that the characteristics of the semiconductors can be tuned by modifying the surface tension of the synthesis mixture. It was observed after the photocatalytic degradation, that the white semiconductor turned to grey. Furthermore, we attempted to explain the gray color of BiOCl catalysts after the photocatalytic decompositions by Raman and XPS studies.
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Affiliation(s)
- Enikő Bárdos
- Department of Applied and Environmental Chemistry, University of Szeged, Rerrich Béla tér 1, HU-6720 Szeged, Hungary; (E.B.); (V.A.M.); (S.F.)
- Institute of Environmental Science and Technology, University of Szeged, Tisza Lajos krt. 103, HU-6720 Szeged, Hungary
| | - Viktória A. Márta
- Department of Applied and Environmental Chemistry, University of Szeged, Rerrich Béla tér 1, HU-6720 Szeged, Hungary; (E.B.); (V.A.M.); (S.F.)
| | - Szilvia Fodor
- Department of Applied and Environmental Chemistry, University of Szeged, Rerrich Béla tér 1, HU-6720 Szeged, Hungary; (E.B.); (V.A.M.); (S.F.)
- Institute of Environmental Science and Technology, University of Szeged, Tisza Lajos krt. 103, HU-6720 Szeged, Hungary
| | - Endre-Zsolt Kedves
- Faculty of Physics, Babeș-Bolyai University, M. Kogălniceanu 1, RO-400084 Cluj-Napoca, Romania;
- Nanostructured Materials and Bio-Nano-Interfaces Center, Institute for Interdisciplinary Research on Bio-Nano-Sciences, Babeș-Bolyai University, Treboniu Laurian 42, RO-400271 Cluj-Napoca, Romania
- Department of Biosystems Engineering, Faculty of Engineering, University of Szeged, Moszkvai krt. 9, H-6725 Szeged, Hungary
| | - Klara Hernadi
- Department of Applied and Environmental Chemistry, University of Szeged, Rerrich Béla tér 1, HU-6720 Szeged, Hungary; (E.B.); (V.A.M.); (S.F.)
- Institute of Physical Metallurgy, Metal Forming and Nanotechnology, University of Miskolc, 3515 Miskolc-Egyetemváros, Hungary
- Correspondence: (K.H.); (Z.P.)
| | - Zsolt Pap
- Department of Applied and Environmental Chemistry, University of Szeged, Rerrich Béla tér 1, HU-6720 Szeged, Hungary; (E.B.); (V.A.M.); (S.F.)
- Institute of Environmental Science and Technology, University of Szeged, Tisza Lajos krt. 103, HU-6720 Szeged, Hungary
- Nanostructured Materials and Bio-Nano-Interfaces Center, Institute for Interdisciplinary Research on Bio-Nano-Sciences, Babeș-Bolyai University, Treboniu Laurian 42, RO-400271 Cluj-Napoca, Romania
- Correspondence: (K.H.); (Z.P.)
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Gyulavári T, Veréb G, Pap Z, Réti B, Baan K, Todea M, Magyari K, Szilágyi IM, Hernadi K. Utilization of Carbon Nanospheres in Photocatalyst Production: From Composites to Highly Active Hollow Structures. MATERIALS 2019; 12:ma12162537. [PMID: 31395835 PMCID: PMC6720943 DOI: 10.3390/ma12162537] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/08/2019] [Revised: 07/26/2019] [Accepted: 08/07/2019] [Indexed: 01/17/2023]
Abstract
Titanium dioxide–carbon sphere (TiO2–CS) composites were constructed via using prefabricated carbon spheres as templates. By the removal of template from the TiO2–CS, TiO2 hollow structures (HS) were synthesized. The CS templates were prepared by the hydrothermal treatment of ordinary table sugar (sucrose). TiO2–HSs were obtained by removing CSs with calcination. Our own sensitized TiO2 was used for coating the CSs. The structure of the CSs, TiO2–CS composites, and TiO2–HSs were characterized by scanning electron microscopy (SEM), infrared spectroscopy (IR), X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), and diffuse reflectance spectroscopy (DRS). The effect of various synthesis parameters (purification method of CSs, precursor quantity, and applied furnace) on the morphology was investigated. The photocatalytic activity was investigated by phenol model pollutant degradation under visible light irradiation (λ > 400 nm). It was established that the composite samples possess lower crystallinity and photocatalytic activity compared to TiO2 hollow structures. Based on XPS measurements, the carbon content on the surface of the TiO2–HS exerts an adverse effect on the photocatalytic performance. The synthesis parameters were optimized and the TiO2–HS specimen having the best absolute and surface normalized photocatalytic efficiency was identified. The superior properties were explained in terms of its unique morphology and surface properties. The stability of this TiO2–HS was investigated via XRD and SEM measurements after three consecutive phenol degradation tests, and it was found to be highly stable as it entirely retained its crystal phase composition, morphology and photocatalytic activity.
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Affiliation(s)
- Tamás Gyulavári
- Research Group of Environmental Chemistry, Institute of Chemistry, University of Szeged, H-6720 Szeged, Tisza Lajos krt. 103, Hungary
- Department of Applied and Environmental Chemistry, University of Szeged, H-6720 Szeged, Rerrich tér 1, Hungary
| | - Gábor Veréb
- Research Group of Environmental Chemistry, Institute of Chemistry, University of Szeged, H-6720 Szeged, Tisza Lajos krt. 103, Hungary.
- Institute of Process Engineering, Faculty of Engineering, University of Szeged, H-6725 Szeged, Moszkvai krt. 9, Hungary.
| | - Zsolt Pap
- Research Group of Environmental Chemistry, Institute of Chemistry, University of Szeged, H-6720 Szeged, Tisza Lajos krt. 103, Hungary.
- Nanostructured Materials and Bio-Nano-Interfaces Center, Interdisciplinary Research Institute on Bio-Nano-Sciences, Babes-Bolyai University, RO-400271 Cluj-Napoca, Treboniu Laurian 42, Romania.
- Institute of Environmental Science and Technology, University of Szeged, H-6720, Szeged, Tisza Lajos krt. 103, Hungary.
| | - Balázs Réti
- Department of Applied and Environmental Chemistry, University of Szeged, H-6720 Szeged, Rerrich tér 1, Hungary
| | - Kornelia Baan
- Department of Applied and Environmental Chemistry, University of Szeged, H-6720 Szeged, Rerrich tér 1, Hungary
| | - Milica Todea
- Nanostructured Materials and Bio-Nano-Interfaces Center, Interdisciplinary Research Institute on Bio-Nano-Sciences, Babes-Bolyai University, RO-400271 Cluj-Napoca, Treboniu Laurian 42, Romania
- Department of Molecular Sciences, Faculty of Medicine, Iuliu Haţieganu University of Medicine and Pharmacy, RO-400012 Cluj-Napoca, Romania
| | - Klára Magyari
- Nanostructured Materials and Bio-Nano-Interfaces Center, Interdisciplinary Research Institute on Bio-Nano-Sciences, Babes-Bolyai University, RO-400271 Cluj-Napoca, Treboniu Laurian 42, Romania
| | - Imre Miklós Szilágyi
- Department of Inorganic and Analytical Chemistry, Budapest University of Technology and Economics, H-1111 Budapest, Hungary
| | - Klara Hernadi
- Research Group of Environmental Chemistry, Institute of Chemistry, University of Szeged, H-6720 Szeged, Tisza Lajos krt. 103, Hungary
- Department of Applied and Environmental Chemistry, University of Szeged, H-6720 Szeged, Rerrich tér 1, Hungary
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Bamba D, Coulibaly M, Robert D. Nitrogen-containing organic compounds: Origins, toxicity and conditions of their photocatalytic mineralization over TiO 2. THE SCIENCE OF THE TOTAL ENVIRONMENT 2017; 580:1489-1504. [PMID: 28041693 DOI: 10.1016/j.scitotenv.2016.12.130] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/03/2016] [Revised: 12/19/2016] [Accepted: 12/19/2016] [Indexed: 05/21/2023]
Abstract
Sustainable water management remains a global concern to meet the food needs of industrial and agricultural activities. Therefore, pollution abatement techniques, cheap and environmentally, are highly desired and recommended. The present review is devoted to the origin and the toxicity of nitrogen-containing organic compounds in water. The progress made in removing these pollutants, in recent years, is addressed. However, a prominent place is given to the photocatalytic degradation process using the TiO2 as a semiconductor, the conditions for good mineralization and especially the factors influencing it. The parameters that impact the performance of this method are the pH, the temperature, the reactor used, the light, the concentration of the pollutant, the amount of catalyst, etc. Up to now, the importance of one parameter relative to another has not been established because in the context of the photocatalytic degradation, certain parameters are often tightly coupled. Consequently, the mineralization is dependent on the initial degree of oxidation of nitrogen atom contained in the pollutant to be degraded. The hydroxyl nitrogen is primarily converted into nitrate ions (NO3-), while the amides and the primary amines are converted into ammonium ions (NH4+).
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Affiliation(s)
- Drissa Bamba
- Laboratoire de Chimie des Eaux (LCE) - Ecole Normale Supérieure d'Abidjan, 08 BP 10 Abidjan 08, Côte d'Ivoire; ICPEES-UMR 7515 CNRS - Université de Strasbourg, Antenne de Saint-Avold, Rue Victor Démange, 57500 Saint-Avold, France.
| | - Mariame Coulibaly
- Laboratoire de Chimie des Eaux (LCE) - Ecole Normale Supérieure d'Abidjan, 08 BP 10 Abidjan 08, Côte d'Ivoire.
| | - Didier Robert
- ICPEES-UMR 7515 CNRS - Université de Strasbourg, Antenne de Saint-Avold, Rue Victor Démange, 57500 Saint-Avold, France.
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