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Gamelas SRD, Tomé JPC, Tomé AC, Lourenço LMO. Advances in photocatalytic degradation of organic pollutants in wastewaters: harnessing the power of phthalocyanines and phthalocyanine-containing materials. RSC Adv 2023; 13:33957-33993. [PMID: 38019980 PMCID: PMC10658578 DOI: 10.1039/d3ra06598g] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2023] [Accepted: 11/08/2023] [Indexed: 12/01/2023] Open
Abstract
Access to clean water is increasingly challenging worldwide due to human activities and climate change. Wastewater treatment and utilization offer a promising solution by reducing the reliance on pure underground water. However, it is crucial to develop efficient and sustainable methods for wastewater purification. Among the emerging wastewater treatment strategies, photocatalysis has gained significant attention for decomposing organic pollutants in water, especially when combined with sunlight and a recoverable photocatalyst. Heterogeneous photocatalysts have distinct advantages, as they can be recovered and reused without significant loss of activity over multiple cycles. Phthalocyanine dyes, with their exceptional photophysical properties, are particularly valuable for homogeneous and heterogeneous photocatalysis. By immobilizing these photosensitizers in various supports, hybrid materials extend their light absorption into the visible spectrum, complementing most supports' limited UV light absorption. The novelty and research importance of this review stems from its discussion of the multifaceted approach to treating contaminated wastewater with phthalocyanines and materials containing phthalocyanines. It highlights key aspects of each study, including photocatalytic efficiency, recyclability characteristics, investigation of the generation of oxygen species responsible for degradation, identification of the major degradation byproducts for each pollutant, and others. Moreover, the review includes tables that illustrate and compare the various phthalocyanines and supporting materials employed in each study for pollutant degradation. Additionally, almost all photocatalysts mentioned in this review could degrade at least 5% of the pollutant, and more than 50 photocatalysts showed photocatalytic rates above 50%. When immobilized in some support, the synergistic effect of the phthalocyanine was visible in the photocatalytic rate of the studied pollutant. However, when performing these types of works, it is necessary to understand the degradation products of each pollutant and their relative toxicities. Along with this, recyclability and stability studies are also necessary. Despite the good results presented in this review, some of the works lack those studies. Moreover, none of the works mentions any study in wastewater.
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Affiliation(s)
- Sara R D Gamelas
- LAQV-REQUIMTE, Department of Chemistry, University of Aveiro 3810-193 Aveiro Portugal
| | - João P C Tomé
- Centro de Química Estrutural, Institute of Molecular Sciences, Departamento de Engenharia Química, Instituto Superior Técnico, Universidade de Lisboa 1049-001 Lisboa Portugal
| | - Augusto C Tomé
- LAQV-REQUIMTE, Department of Chemistry, University of Aveiro 3810-193 Aveiro Portugal
| | - Leandro M O Lourenço
- LAQV-REQUIMTE, Department of Chemistry, University of Aveiro 3810-193 Aveiro Portugal
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Sindelo A, Britton J, Lanterna AE, Scaiano JC, Nyokong T. Decoration of glass wool with zinc (II) phthalocyanine for the photocatalytic transformation of methyl orange. J Photochem Photobiol A Chem 2022. [DOI: 10.1016/j.jphotochem.2022.114127] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/31/2022]
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3
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The photocatalytic properties of zinc phthalocyanines supported on hematite nanofibers for use against methyl orange and Staphylococcus aureus. J Photochem Photobiol A Chem 2022. [DOI: 10.1016/j.jphotochem.2021.113637] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
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4
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Ergün AB, Sevim AM, Kılıç A, Gül A. Metallophthalocyanine/polyacrylonitrile nanofibers by solution blow spinning technique for enhanced photocatalytic activity by visible light. J Appl Polym Sci 2021. [DOI: 10.1002/app.50115] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Affiliation(s)
- Anıl Berk Ergün
- TEMAG Lab Istanbul Technical University Istanbul Turkey
- Department of Chemistry Istanbul Technical University Istanbul Turkey
| | - Altuğ Mert Sevim
- Department of Chemistry Istanbul Technical University Istanbul Turkey
| | - Ali Kılıç
- TEMAG Lab Istanbul Technical University Istanbul Turkey
| | - Ahmet Gül
- Department of Chemistry Istanbul Technical University Istanbul Turkey
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Mgidlana S, Nwahara N, Nyokong T. Photocatalytic desulfurization of dibenzothiophene using methoxy substituted asymmetrical zinc(II) phthalocyanines conjugated to metal tungstate nanomaterials. Polyhedron 2021. [DOI: 10.1016/j.poly.2021.115053] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
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6
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Mgidlana S, Nyokong T. Photocatalytic desulfurization of dibenzothiophene using asymmetrical zinc(II) phthalocyanines conjugated to silver-magnetic nanoparticles. Inorganica Chim Acta 2021. [DOI: 10.1016/j.ica.2020.119970] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
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Navaei Z, Zanjanchi MA. Synthesis of an efficient photocatalyst by incorporation of phthalocyanine into KIT-6. SN APPLIED SCIENCES 2020. [DOI: 10.1007/s42452-020-2845-6] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022] Open
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Fabrication of Hybrid Membranes Containing Nylon-11 and Organic Semiconductor Particles with Potential Applications in Molecular Electronics. Polymers (Basel) 2019; 12:polym12010009. [PMID: 31861628 PMCID: PMC7023623 DOI: 10.3390/polym12010009] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2019] [Revised: 12/09/2019] [Accepted: 12/11/2019] [Indexed: 02/05/2023] Open
Abstract
Chemical degradation is a major disadvantage in the development of organic semiconductors. This work proposes the manufacture and characterization of organic semiconductor membranes in order to prevent semiconductor properties decreasing. Semiconductor membranes consisting of Nylon-11 and particles of π-conjugated molecular semiconductors were manufactured by high-vacuum evaporation followed by thermal relaxation. Initially, and with the aim of obtaining semiconductor particles, bulk heterojunction (BHJ) was carried out using green chemistry techniques between the zinc phthalocyanine (ZnPc) and the zinc hexadecafluoro-phthalocyanine (F16ZnPc) as n-type molecular semiconductors with the p-type molecular semiconductor dibenzotetrathiafulvalene (DBTTF). Consequently, the π-conjugated semiconductors particles were embedded in a Nylon-11 matrix and characterized, both structurally and considering their optical and electrical properties. Thin films of these materials were manufactured in order to comparatively study the membranes and precursor semiconductor particles. The membranes presented bandgap (Eg) values that were lower than those obtained in the films, which is an indicator of an improvement in their semiconductor capacity. Finally, the membranes were subjected to accelerated lighting conditions, to determine the stability of the polymer and the operating capacity of the membrane. After fatigue conditions, the electrical behavior of the proposed semiconductor membranes remained practically unaltered; therefore, they could have potential applications in molecular electronics. The chemical stability of membranes, which did not degrade in their polymer compound, nor in the semiconductor, was monitored by IR spectroscopy.
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Dilber G, Altunparmak H, Nas A, Kantekin H, Durmuş M. The peripheral and non-peripheral 2H-benzotriazole substituted phthalocyanines: Synthesis, characterization, photophysical and photochemical studies of zinc derivatives. SPECTROCHIMICA ACTA. PART A, MOLECULAR AND BIOMOLECULAR SPECTROSCOPY 2019; 217:128-140. [PMID: 30928838 DOI: 10.1016/j.saa.2019.01.095] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/11/2018] [Revised: 01/14/2019] [Accepted: 01/16/2019] [Indexed: 06/09/2023]
Abstract
In this study, the novel 3-(1H-benzo[d][1,2,3]triazol-1-yl)methoxy substituted novel phthalonitrile compounds (2 and 6) were synthesized. Their non-peripheral and peripheral zinc (II) (3 and 7), manganese (III) (4 and 8) and copper (II) (5 and 9) phthalocyanine complexes were synthesized for the first time. These novel compounds were characterized by elemental analysis and different spectroscopic techniques such as FT-IR, UV-Vis, 1H NMR, 13C NMR and MALDI-TOF mass. Also, photochemical and photophysical properties of non-peripheral and peripheral substituted zinc (II) phthalocyanines (3 and 7) were investigated for determination of photodynamic therapy applications of these phthalocyanines.
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Affiliation(s)
- Gülsev Dilber
- Macka Vocational School, Karadeniz Technical University, 61750 Macka, Trabzon, Turkey
| | - Hasan Altunparmak
- Department of Chemistry, Karadeniz Technical University, 61080 Trabzon, Turkey
| | - Asiye Nas
- Macka Vocational School, Karadeniz Technical University, 61750 Macka, Trabzon, Turkey.
| | - Halit Kantekin
- Department of Chemistry, Karadeniz Technical University, 61080 Trabzon, Turkey
| | - Mahmut Durmuş
- Gebze Technical University, Department of Chemistry, Gebze 41400, Kocaeli, Turkey
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Mapukata S, Osifeko OL, Nyokong T. Dual phototransformation of the pollutants methyl orange and Cr (VI) using phthalocyanine-cobalt ferrite based magnetic nanocomposites. Heliyon 2019; 5:e01509. [PMID: 31025016 PMCID: PMC6476804 DOI: 10.1016/j.heliyon.2019.e01509] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2018] [Revised: 02/06/2019] [Accepted: 04/08/2019] [Indexed: 11/06/2022] Open
Abstract
Bifunctional nanocomposites based on zinc phthalocyanines and glutathione capped CoFe2O4 magnetic nanoparticles (GSH-CoFe2O4 MNPs) are applied in a binary system wherein simultaneous photooxidation of methyl orange (MO) and photoreduction of Cr (VI) are conducted. The photoactivity of two zinc Pcs with different functional moieties are compared based on their interactions with GSH-CoFe2O4 MNPs. Conjugation of the Pcs to the GSH-CoFe2O4 MNPs not only enhanced their singlet oxygen production but also their photocatalytic activity in both photooxidation and photoreduction experiments. Using electron paramagnetic resonance (EPR) spectroscopy, the Pc-MNP conjugates reported herein were found to exhibit superparamagnetic behaviour, giving the advantage of easy separation using an external magnetic field post application, an attractive attribute for heterogeneous catalysis. The catalysts reported herein are therefore good candidates as catalysts for real life water purification analyses as they facilitate the treatment of both organic and inorganic water pollutants.
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Affiliation(s)
| | | | - Tebello Nyokong
- Centre for Nanotechnology Innovation, Department of Chemistry, Rhodes University, Grahamstown 6140, South Africa
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A comparative study of the singlet oxygen generation capability of a zinc phthalocyanine linked to graphene quantum dots through π-π stacking and covalent conjugation when embedded in asymmetric polymer membranes. J Mol Struct 2019. [DOI: 10.1016/j.molstruc.2018.11.096] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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12
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Nwahara N, Nkhahle R, Ngoy BP, Mack J, Nyokong T. Synthesis and photophysical properties of BODIPY-decorated graphene quantum dot–phthalocyanine conjugates. NEW J CHEM 2018. [DOI: 10.1039/c8nj00758f] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
A BODIPY dye is linked to graphene quantum dots followed by immobilization of a Zn phthalocyanineviaπ–π stacking, resulting in improved triplet and singlet oxygen quantum yields.
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Affiliation(s)
- Nnamdi Nwahara
- Department of Chemistry
- Rhodes University
- Grahamstown 6140
- South Africa
| | | | - Bokolombe P. Ngoy
- Department of Chemistry
- Rhodes University
- Grahamstown 6140
- South Africa
| | - John Mack
- Department of Chemistry
- Rhodes University
- Grahamstown 6140
- South Africa
| | - Tebello Nyokong
- Department of Chemistry
- Rhodes University
- Grahamstown 6140
- South Africa
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New Development of Membrane Base Optoelectronic Devices. Polymers (Basel) 2017; 10:polym10010016. [PMID: 30966051 PMCID: PMC6415192 DOI: 10.3390/polym10010016] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2017] [Revised: 12/19/2017] [Accepted: 12/21/2017] [Indexed: 11/30/2022] Open
Abstract
It is known that one factor that affects the operation of optoelectronic devices is the effective protection of the semiconductor materials against environmental conditions. The permeation of atmospheric oxygen and water molecules into the device structure induces degradation of the electrodes and the semiconductor. As a result, in this communication we report the fabrication of semiconductor membranes consisting of Magnesium Phthalocyanine-allene (MgPc-allene) particles dispersed in Nylon 11 films. These membranes combine polymer properties with organic semiconductors properties and also provide a barrier effect for the atmospheric gas molecules. They were prepared by high vacuum evaporation and followed by thermal relaxation technique. For the characterization of the obtained membranes, Fourier-transform infrared spectroscopy (FT-IR), scanning electron microscopy (SEM), and energy dispersive spectroscopy (EDS) were used to determine the chemical and microstructural properties. UV-ViS, null ellipsometry, and visible photoluminescence (PL) at room temperature were used to characterize the optoelectronic properties. These results were compared with those obtained for the organic semiconductors: MgPc-allene thin films. Additionally, semiconductor membranes devices have been prepared, and a study of the device electronic transport properties was conducted by measuring electrical current density-voltage (J-V) characteristics by four point probes with different wavelengths. The resistance properties against different environmental molecules are enhanced, maintaining their semiconductor functionality that makes them candidates for optoelectronic applications.
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Mafukidze DM, Mashazi P, Nyokong T. Synthesis and singlet oxygen production by a phthalocyanine when embedded in asymmetric polymer membranes. POLYMER 2016. [DOI: 10.1016/j.polymer.2016.10.032] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
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15
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Çolak S, Durmuş M, Yıldız SZ. Investigation of the photophysical and photochemical properties of peripherally tetra-substituted water-soluble zwitterionic and cationic zinc(ii) phthalocyanines. Dalton Trans 2016; 45:10402-10. [DOI: 10.1039/c6dt01084a] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
Abstract
4-{4-[N-((3-Dimethylamino)propyl)amide]phenoxy} substituted zinc(ii) phthalocyanine (2) and its water-soluble sulfobetaine (3), betaine (4) and N-oxide (5) containing zwitterionic and cationic (6) derivatives were synthesized for the first time in this study.
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Affiliation(s)
- Senem Çolak
- Sakarya University
- Faculty of Arts and Sciences
- Department of Chemistry
- Sakarya
- Turkey
| | - Mahmut Durmuş
- Gebze Technical University
- Department of Chemistry
- Kocaeli
- Turkey
| | - Salih Zeki Yıldız
- Sakarya University
- Faculty of Arts and Sciences
- Department of Chemistry
- Sakarya
- Turkey
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Jiang H, Sun Y, Feng J, Wang J. Heterogeneous electro-Fenton oxidation of azo dye methyl orange catalyzed by magnetic Fe3O4 nanoparticles. WATER SCIENCE AND TECHNOLOGY : A JOURNAL OF THE INTERNATIONAL ASSOCIATION ON WATER POLLUTION RESEARCH 2016; 74:1116-1126. [PMID: 27642831 DOI: 10.2166/wst.2016.300] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
Azo dye methyl orange (MO) degradation by heterogeneous electro-Fenton (EF) with a magnetic nano-Fe3O4 catalyst was investigated. In this study, Fe3O4 was synthesized by a coprecipitation method and characterized by X-ray diffraction and scanning electron microscopy. The influences of the main operating parameters such as current density, pH, catalyst dosage and aeration rate were studied. The results revealed that higher current density, catalyst dosage and aeration rate facilitated the degradation of MO, whereas the degradation efficiency of MO was decreased with an increase in the initial pH. After 90 min EF process, the volume of 500 mL, the initial concentration of 50 mg L(-1) MO solution could be degraded by 86.6% with the addition of 1 g L(-1) Fe3O4 under the current density of 10 mA cm(-2) and pH 3, compared with 69.5% for the electrolytic process alone. Meanwhile, a total organic carbon removal of 32% was obtained, up to 35.5 mg L(-1) accumulated H2O2 and less than 3.5 mg L(-1) Fe leaching were detected. Moreover, based on the results of natural bond orbital (at B3LYP/6-311G (d, p)) and liquid chromatograph-triple quadrupole mass spectrometer analysis, nine intermediates were identified and the proposed degradation pathways were investigated.
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Affiliation(s)
- Hao Jiang
- State Key Laboratory of Pollution Control and Resources Reuse, School of the Environment, Nanjing University, Nanjing 210046, China E-mail:
| | - Yabing Sun
- State Key Laboratory of Pollution Control and Resources Reuse, School of the Environment, Nanjing University, Nanjing 210046, China E-mail:
| | - Jingwei Feng
- School of Civil and Hydraulic Engineering, Hefei University of Technology, Hefei 230009, China and State Key Laboratory of Hydrology-Water Resources and Hydraulic Engineering, Hohai University, Nanjing 210098, China
| | - Jian Wang
- State Key Laboratory of Pollution Control and Resources Reuse, School of the Environment, Nanjing University, Nanjing 210046, China E-mail:
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Application of photoactive electrospun nanofiber materials with immobilized meso-tetraphenylporphyrin for parabens photodegradation. Catal Today 2015. [DOI: 10.1016/j.cattod.2014.06.015] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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Khoza P, Nyokong T. Photocatalytic behavior of phthalocyanine-silver nanoparticle conjugates supported on polystyrene fibers. ACTA ACUST UNITED AC 2014. [DOI: 10.1016/j.molcata.2014.07.031] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
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Fei BL, Yan QL, Wang JH, Liu QB, Long JY, Li YG, Shao KZ, Su ZM, Sun WY. Green Oxidative Degradation of Methyl Orange with Copper(II) Schiff Base Complexes as Photo-Fenton-Like Catalysts. Z Anorg Allg Chem 2014. [DOI: 10.1002/zaac.201300562] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
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Ding S, Niu J, Bao Y, Hu L. Evidence of superoxide radical contribution to demineralization of sulfamethoxazole by visible-light-driven Bi2O3/Bi2O2CO3/Sr6Bi2O9 photocatalyst. JOURNAL OF HAZARDOUS MATERIALS 2013; 262:812-818. [PMID: 24140532 DOI: 10.1016/j.jhazmat.2013.09.048] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/13/2013] [Revised: 09/19/2013] [Accepted: 09/20/2013] [Indexed: 06/02/2023]
Abstract
Photocatalytic degradation of sulfamethoxazole (SMX) was investigated using Bi2O3/Bi2O2CO3/Sr6Bi2O9 (BSO) photocatalyst under visible light (>420 nm) irradiation. The photochemical degradation of SMX followed pseudo-first-order kinetics. The reaction kinetics was determined as a function of initial SMX concentrations (5-20 mg L(-1)), initial pH (3-11) and BSO concentrations (6-600 mg L(-1)). Approximately, 90% of SMX (10 mg L(-1)) degradation and 36% of TOC reduction were achieved at pH 7.0 after 120 min irradiation. The main mineralization products, including NH4(+), NO3(-), SO4(2-) and CO2, as well as intermediates 3-amino-5-methylisoxazole (AMI), p-benzoquinone (BZQ), and sulfanilic acid (SNA) were detected in aqueous solution. The formation of O2(*-) radical was evidenced by using electron spin resonance and a chemiluminescent probe, luminal. A possible degradation mechanism involving excitation of BSO, followed by charge injection into the BSO conduction band and formation of reactive superoxide radical (O2(*-)) was proposed for the mineralization of SMX. During the reaction, the O2(*-) radical attacks the sulfone moiety and causes the cleavage of the SN bond, which leads to the formation of two sub-structure analogs, AMI and SNA.
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Affiliation(s)
- Shiyuan Ding
- State Key Laboratory of Water Environment Simulation, School of Environment, Beijing Normal University, Beijing 100875, PR China
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Niu J, Ding S, Zhang L, Zhao J, Feng C. Visible-light-mediated Sr-Bi2O3 photocatalysis of tetracycline: kinetics, mechanisms and toxicity assessment. CHEMOSPHERE 2013; 93:1-8. [PMID: 23706401 DOI: 10.1016/j.chemosphere.2013.04.043] [Citation(s) in RCA: 58] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/03/2013] [Revised: 03/17/2013] [Accepted: 04/17/2013] [Indexed: 06/02/2023]
Abstract
Photodegradation of tetracycline (TC) was investigated in aqueous solution by visible-light-driven photocatalyst Sr-doped β-Bi2O3 (Sr-Bi2O3) prepared via solvothermal synthesis. The decomposition of TC by Sr-Bi2O3 under visible light (λ>420nm) irradiation followed pseudo-first-order kinetics, and the removal ratio reached 91.2% after 120min of irradiation. Sr-Bi2O3 photocatalysis is able to break the naphthol ring of TC which decomposes to m-cresol via dislodging hydroxyl group step by step by photogenerated electron. This mechanism was verified by electron spin resonance measurement, the addition of radical scavengers and the intermediate product analysis, indicating that the photogenerated electron acts as a reductant and can be the key to the degradation process. In contrast, in TiO2 photocatalysis the naphthol ring is broken via oxidation by hydroxyl radical, while in direct photolysis the ring remains intact. In addition, the toxicity of photodegradation products was analyzed by bioluminescence inhibition. After 120min of irradiation by Sr-Bi2O3, the toxicity decreases by 90.6%, which is more substantial than direct photolysis (70%) and TiO2 photocatalysis (80%), indicating that the Sr-Bi2O3 photocatalysis is more eco-friendly than the other two methods.
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Affiliation(s)
- Junfeng Niu
- State Key Laboratory of Water Environment Simulation, School of Environment, Beijing Normal University, Beijing 100875, PR China.
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