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Ebrahimpour Z, Pliekhova O, Cabrera H, Abdelhamid M, Korte D, Segbéya Gadedjisso-Tossou K, Niemela J, Lavrencic Stangar U, Franko M. Photodegradation mechanisms of reactive blue 19 dye under UV and simulated solar light irradiation. SPECTROCHIMICA ACTA. PART A, MOLECULAR AND BIOMOLECULAR SPECTROSCOPY 2021; 252:119481. [PMID: 33524821 DOI: 10.1016/j.saa.2021.119481] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/13/2020] [Revised: 01/01/2021] [Accepted: 01/09/2021] [Indexed: 06/12/2023]
Abstract
In this work we performed dye photodegradation experiments in presence of TiO2 and Cu/Zr modified TiO2. The changes in the shape of the spectra of RB19 caused by photocatalysts under the simulated solar or UV light were monitored. Since the predominant photocatalytic mechanism can only be observed in very dilute solution of RB19, UV-Vis absorption spectrometry for higher concentrations and thermal lens spectrometry for lower concentrations have been applied to elucidate the mechanistic details of degradation processes. Bleaching of the dye was a characteristic feature, that occurred under both simulated solar and UV lights. It was also evident, that the absorption peak with maximum centered at 592 nm undergoes a slight blue shift during irradiation. The experiments carried out using UV and simulated solar light demonstrated, that two different processes responsible for the RB19 dye degradation occurred. In the initial stage of irradiation one of the processes appears under the UV light and can be recognized by a characteristic blue shift in the absorption spectrum of the solution. The second process is characteristic for irradiation by the simulated solar light which involve a blue shift at longer periods (100 min). These phenomena were attributed to the photocatalytic and photosensitization mechanisms, respectively. However, photocatalytic mechanism was also observed under simulated solar radiation, when the initial dye concentration was decreased to 5 mgL-1, and was recognized by the increase of the thermal lens signal during the initial stages of degradation process. This was possible because the thermal lens spectroscopy technique provides a limit of quantification for RB19 at the concentration level of 0.12 mg L-1, while UV-Vis spectrometry enables quantification of RB19 only down to 4 mg L-1 levels.
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Affiliation(s)
- Zeinab Ebrahimpour
- Optics Lab., The Abdus Salam International Centre for Theoretical Physics (ICTP), Strada Costiera 11, Trieste, Italy
| | - Olena Pliekhova
- Laboratory for Environmental and Life Sciences, University of Nova Gorica, Vipavska 13, Nova Gorica 5000, Slovenia
| | - Humberto Cabrera
- Optics Lab., The Abdus Salam International Centre for Theoretical Physics (ICTP), Strada Costiera 11, Trieste, Italy.
| | - Mahmoud Abdelhamid
- Optics Lab., The Abdus Salam International Centre for Theoretical Physics (ICTP), Strada Costiera 11, Trieste, Italy; National Institute of Laser Enhanced Sciences (NILES), Cairo University, Giza, Egypt
| | - Dorota Korte
- Laboratory for Environmental and Life Sciences, University of Nova Gorica, Vipavska 13, Nova Gorica 5000, Slovenia.
| | - Komlan Segbéya Gadedjisso-Tossou
- Optics Lab., The Abdus Salam International Centre for Theoretical Physics (ICTP), Strada Costiera 11, Trieste, Italy; Laboratoire de Physique des Matériaux et Composants à Semi-conducteurs (LPMCS), Département de Physique, Université de Lomé, Togo
| | - Joseph Niemela
- Optics Lab., The Abdus Salam International Centre for Theoretical Physics (ICTP), Strada Costiera 11, Trieste, Italy
| | - Urska Lavrencic Stangar
- Laboratory for Environmental and Life Sciences, University of Nova Gorica, Vipavska 13, Nova Gorica 5000, Slovenia; Faculty of Chemistry and Chemical Technology, University of Ljubljana, Vecna pot 113, 1000 Ljubljana, Slovenia
| | - Mladen Franko
- Laboratory for Environmental and Life Sciences, University of Nova Gorica, Vipavska 13, Nova Gorica 5000, Slovenia
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Tuna Ö, Bilgin Simsek E, Sarıoğlan A, Durak Çetin Y. Multifunctional and highly active zinc titanate incorporated with copper for adsorptive hot syngas desulfurization and photocatalytic dye degradation. J Taiwan Inst Chem Eng 2020. [DOI: 10.1016/j.jtice.2020.04.008] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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