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Seifikar F, Habibi-Yangjeh A. Floating photocatalysts as promising materials for environmental detoxification and energy production: A review. CHEMOSPHERE 2024; 355:141686. [PMID: 38513952 DOI: 10.1016/j.chemosphere.2024.141686] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/07/2024] [Revised: 03/08/2024] [Accepted: 03/10/2024] [Indexed: 03/23/2024]
Abstract
The oxygenation process of the catalyst surface, the incident-light harvesting capability, and facile recycling of utilized photocatalysts play key role in the outstanding photocatalytic performances. The typical existing photocatalysts in powder form have many drawbacks, such as difficult separation from the treated water, insufficient surface oxygenation, poor active surface area, low incident-light harvesting ability, and secondary pollution of the environment. A great number of scientific works introduced novel and fresh ideas related to designing floating photocatalytic systems by immobilizing highly active photocatalysts onto a floatable substrate. Thanks to direct contact with the illuminated light and oxygen molecules in the interface of water/air, the photocatalytic performance is maximized through production of more reactive species, employed in the photocatalytic reactions. Furthermore, facile recovering of the utilized photocatalysts for next processes avoids secondary pollution as well as diminishes the process's price. This review highlights the performance of developed floating photocatalysts for diverse applications. Furthermore, different floating substrates and possible mechanisms in floating photocatalysts are briefly mentioned. In addition, several emerging self-floating photocatalytic systems are taken attention and discussed. Specially, coupling photo-thermal and photocatalytic effects seems to be a good strategy for introducing a new class of floating photocatalyst to utilize the free, abundant, and green sunlight energy for the aims of water desalination and purification. Despite of a large number of attempts about the floating photocatalysts, there are still plenty of rooms for more in-depth research to be carried out for attaining the required characteristics of the large scale utilizations of these materials.
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Affiliation(s)
- Fatemeh Seifikar
- Department of Chemistry, Faculty of Science, University of Mohaghegh Ardabili, Ardabil, Iran
| | - Aziz Habibi-Yangjeh
- Department of Chemistry, Faculty of Science, University of Mohaghegh Ardabili, Ardabil, Iran.
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Sebabi M, Mabuba N, Pillay K, Malinga SP. Hyperbranched-Polyethylenimine-Functionalized Coal Fly Ash as an Adsorbent for the Removal of Hexavalent Chromium and Reuse as a Dye Photocatalyst. ACS OMEGA 2024; 9:8954-8972. [PMID: 38434891 PMCID: PMC10905742 DOI: 10.1021/acsomega.3c06491] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 09/18/2023] [Revised: 12/27/2023] [Accepted: 01/10/2024] [Indexed: 03/05/2024]
Abstract
Coal fly ash (CFA) has been extensively researched as an adsorbent for heavy metals, but its application is limited by its low adsorption capacity. The modification of CFA with hyperbranched polymers results in improved adsorption capacities. Hyperbranched polyethylenimine (HPEI) is a hyperbranched polymer containing NH2 groups that can bind with heavy metal ions through complexation or electrostatic interactions. In this study, CFA-HPEI adsorbents with various HPEI loadings (1-5%) were prepared and evaluated for the removal of Cr(VI). The successful incorporation of HPEI onto CFA was confirmed using Fourier transform infrared, elemental analysis, and X-ray photoelectron spectroscopy (XPS). The 3% CFA-HPEI loaded adsorbent resulted in optimum results when the effect of pH and adsorbent dosage was studied. The pseudo-second-order kinetics model best described the adsorption kinetics at an initial concentration of 20 mg/L. The Freundlich adsorption isotherm model best fitted the equilibrium adsorption data with a maximum adsorption capacity of 85.93 mg/g. The Cr-loaded adsorbent was reused as a photocatalyst to degrade methylene blue (MB) in the presence of visible light. The loaded adsorbent degraded 98.9% of MB (5 mg/L) within 180 min and was accompanied by compounds with m/z of 173 and 234, corresponding to the intermediate degradation of Azure A. The XPS analysis confirmed the coexistence of Cr(III) and Cr(VI) on the surface of the adsorbent. In addition, the loaded adsorbent exhibited good stability following MB degradation with no structural changes observed. Thus, CFA-HPEI adsorbents can be utilized as low-cost adsorbents for the remediation of toxic Cr(VI) from water and wastewater. The Cr-loaded CFA-HPEI adsorbent can be effectively reused as a photocatalyst, thus reducing environmental pollution.
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Affiliation(s)
- Molahlegi
Orienda Sebabi
- Department
of Chemical Sciences, University of Johannesburg, P.O. Box 17011, Doornfontein 2028, South Africa
- Spectrum, University
of Johannesburg, P.O. Box 524, Auckland Park 2006, South Africa
| | - Nonhlangabezo Mabuba
- Department
of Chemical Sciences, University of Johannesburg, P.O. Box 17011, Doornfontein 2028, South Africa
| | - Kriveshini Pillay
- Department
of Chemical Sciences, University of Johannesburg, P.O. Box 17011, Doornfontein 2028, South Africa
| | - Soraya Phumzile Malinga
- Department
of Chemical Sciences, University of Johannesburg, P.O. Box 17011, Doornfontein 2028, South Africa
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dela Rosa FM, Popović M, Papac Zjačić J, Radić G, Kraljić Roković M, Kovačić M, Farré MJ, Genorio B, Lavrenčič Štangar U, Kušić H, Lončarić Božić A, Petrović M. Visible-Light Activation of Persulfate or H 2O 2 by Fe 2O 3/TiO 2 Immobilized on Glass Support for Photocatalytic Removal of Amoxicillin: Mechanism, Transformation Products, and Toxicity Assessment. NANOMATERIALS (BASEL, SWITZERLAND) 2022; 12:4328. [PMID: 36500951 PMCID: PMC9738309 DOI: 10.3390/nano12234328] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 11/15/2022] [Revised: 12/01/2022] [Accepted: 12/02/2022] [Indexed: 06/17/2023]
Abstract
Fe2O3/TiO2 nanocomposites were fabricated via a facile impregnation/calcination technique employing different amounts iron (III) nitrate onto commercial TiO2 (P25 Aeroxide). The as-prepared Fe2O3/TiO2 nanocomposites were characterized by X-ray diffraction (XRD), Raman spectroscopy (RS), scanning electron microscopy/energy-dispersive spectroscopy (SEM/EDXS), X-ray photoelectron spectroscopy (XPS), Brunauer-Emmett-Teller analysis (BET), electron impedance spectroscopy (EIS), photoluminescence spectroscopy (PL), and diffuse reflectance spectroscopy (DRS). As a result, 5% (w/w) Fe2O3/TiO2 achieved the highest photocatalytic activity in the slurry system and was successfully immobilized on glass support. Photocatalytic activity under visible-light irradiation was assessed by treating pharmaceutical amoxicillin (AMX) in the presence and absence of additional oxidants: hydrogen peroxide (H2O2) and persulfate salts (PS). The influence of pH and PS concentration on AMX conversion rate was established by means of statistical planning and response surface modeling. Results revealed optimum conditions of [S2O82-] = 1.873 mM and pH = 4.808; these were also utilized in presence of H2O2 instead of PS in long-term tests. The fastest AMX conversion possessing a zero-order rate constant of 1.51 × 10-7 M·min-1 was achieved with the photocatalysis + PS system. The AMX conversion pathway was established, and the evolution/conversion of formed intermediates was correlated with the changes in toxicity toward Vibrio fischeri. Reactive oxygen species (ROS) scavenging was also utilized to investigate the AMX conversion mechanism, revealing the major contribution of photogenerated h+ in all processes.
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Affiliation(s)
- Francis M. dela Rosa
- Faculty of Chemical Engineering and Technology, University of Zagreb, Marulićev trg 19, 10000 Zagreb, Croatia
- Catalan Institute for Water Research (ICRA), C/Emili Grahit, 101, 17003 Girona, Spain
- Faculty of Sciences, University of Girona, 17071 Girona, Spain
| | - Marin Popović
- Department of Safety and Protection, Karlovac University of Applied Sciences, Trg J.J. Strossmayera 9, 47000 Karlovac, Croatia
| | - Josipa Papac Zjačić
- Faculty of Chemical Engineering and Technology, University of Zagreb, Marulićev trg 19, 10000 Zagreb, Croatia
| | - Gabrijela Radić
- Faculty of Chemical Engineering and Technology, University of Zagreb, Marulićev trg 19, 10000 Zagreb, Croatia
| | - Marijana Kraljić Roković
- Faculty of Chemical Engineering and Technology, University of Zagreb, Marulićev trg 19, 10000 Zagreb, Croatia
| | - Marin Kovačić
- Faculty of Chemical Engineering and Technology, University of Zagreb, Marulićev trg 19, 10000 Zagreb, Croatia
| | - María José Farré
- Catalan Institute for Water Research (ICRA), C/Emili Grahit, 101, 17003 Girona, Spain
| | - Boštjan Genorio
- Faculty of Chemistry and Chemical Technology, University of Ljubljana, Vecna pot 113, 1000 Ljubljana, Slovenia
| | - Urška Lavrenčič Štangar
- Faculty of Chemistry and Chemical Technology, University of Ljubljana, Vecna pot 113, 1000 Ljubljana, Slovenia
| | - Hrvoje Kušić
- Faculty of Chemical Engineering and Technology, University of Zagreb, Marulićev trg 19, 10000 Zagreb, Croatia
| | - Ana Lončarić Božić
- Faculty of Chemical Engineering and Technology, University of Zagreb, Marulićev trg 19, 10000 Zagreb, Croatia
| | - Mira Petrović
- Catalan Institute for Water Research (ICRA), C/Emili Grahit, 101, 17003 Girona, Spain
- Catalan Institution for Research and Advanced Studies (ICREA), Passeig Lluis Companys 23, 08010 Barcelona, Spain
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Son BT, Long NV, Nhat Hang NT. Fly ash-, foundry sand-, clay-, and pumice-based metal oxide nanocomposites as green photocatalysts. RSC Adv 2021; 11:30805-30826. [PMID: 35498918 PMCID: PMC9041310 DOI: 10.1039/d1ra05647f] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/2021] [Accepted: 09/02/2021] [Indexed: 12/12/2022] Open
Abstract
Metal oxides possess exceptional physicochemical properties which make them ideal materials for critical photocatalytic applications. However, of major interest, their photocatalytic applications are hampered by several drawbacks, consisting of prompt charge recombination of charge carriers, low surface area, inactive under visible light, and inefficient as well as expensive post-treatment recovery. The immobilization of metal oxide semiconductors on materials possessing high binding strength eliminates the impractical and costly recovery of spent catalysts in large-scale operations. Notably, the synthesis of green material (ash, clay, foundry sand, and pumice)-based metal oxides could provide a synergistic effect of the superior adsorption capacity of supporting materials and the photocatalytic activity of metal oxides. This phenomenon significantly improves the overall degradation efficiency of emerging pollutants. Inspired by the novel concept of "treating waste with waste", this contribution highlights recent advances in the utilization of natural material (clay mineral and pumice)- and waste material (ash and foundry sand)-based metal oxide nanocomposites for photodegradation of various pollutants. First, principles, mechanism, challenges towards using metal oxide as photocatalysts, and immobilization techniques are systematically summarized. Then, sources, classifications, properties, and chemical composition of green materials are briefly described. Recent advances in the utilization of green materials-based metal oxide composites for the photodegradation of various pollutants are highlighted. Finally, in the further development of green materials-derived photocatalysts, we underlined the current gaps that are worthy of deeper research in the future.
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Affiliation(s)
- Bui Thanh Son
- Nanotechnology, Thu Dau Mot University Binh Duong Province Vietnam
| | - Nguyen Viet Long
- Nanotechnology, Thu Dau Mot University Binh Duong Province Vietnam
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Gadore V, Ahmaruzzaman M. Fly ash-based nanocomposites: a potential material for effective photocatalytic degradation/elimination of emerging organic pollutants from aqueous stream. ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH INTERNATIONAL 2021; 28:46910-46933. [PMID: 34263399 DOI: 10.1007/s11356-021-15251-0] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/27/2021] [Accepted: 06/28/2021] [Indexed: 06/13/2023]
Abstract
Fly ash is readily available and cheaply generated as 47a by-product of the combustion of organic matter. A tremendous amount of fly ash is generated worldwide, and its disposal has imposed 47a severe environmental concern. Its good adsorption capacities attracted several researchers to study the use of fly ash as 47a support for photocatalysts for the degradation of contaminants from wastewater. Undoubtedly the photocatalysts supported on fly ash have represented excellent degradation efficiencies due to the synergistic effect of adsorption and photocatalytic capacity. The utilization of fly ash as 47a precursor has solved the problem of disposal and added value to the waste by-product. Various preparation techniques for fly ash-based nanocomposites such as the sol-gel method, hydrothermal method, solvothermal method, precipitation and co-precipitation, modified metalorganic decomposition, electrospinning, incipient impregnation, and wet chemical synthesis, along with 47a brief study of their characterization using scanning electron microscopy, X-ray diffraction technique and Fourier transform infrared (FTIR) spectroscopy, and the mechanism of photodegradation of dyes have been discussed in this paper. The literature shows that SiO2, TiO2, and Al2O3 present in fly ash play an essential role in the photodegradation of dyes. Factors affecting the degradation of dyes, their kinetic studies, and methods to enhance photodegradation efficiency have also been discussed.
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Affiliation(s)
- Vishal Gadore
- Department of Chemistry, National Institute of Technology, Silchar, Assam, 788010, India
| | - Md Ahmaruzzaman
- Department of Chemistry, National Institute of Technology, Silchar, Assam, 788010, India.
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Yang Q, Fang C, Zhao N, Jiang Y, Xu B, Chai S, Zhou Y. Enhancing electron-hole utilization of CdS Based on cucurbiturils vis electrostatic interaction in visible light. J SOLID STATE CHEM 2019. [DOI: 10.1016/j.jssc.2018.11.017] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
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Liu S, Zhu D, Zhu J, Yang Q, Wu H. Preparation of Ag@AgCl-doped TiO 2/sepiolite and its photocatalytic mechanism under visible light. J Environ Sci (China) 2017; 60:43-52. [PMID: 29031445 DOI: 10.1016/j.jes.2016.12.026] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/18/2016] [Revised: 10/08/2016] [Accepted: 12/13/2016] [Indexed: 06/07/2023]
Abstract
A cube-like Ag@AgCl-doped TiO2/sepiolite (denoted Ag@AgCl-TiO2/sepiolite) was successfully synthesized via a novel method. X-ray diffraction, scanning electron microscopy, energy dispersion X-ray fluorescence, X-ray photoelectron spectroscopy, Fourier transform infrared spectroscopy, and diffuse reflectance ultraviolet-visible spectroscopy were performed to determine the structure and physicochemical properties of Ag@AgCl-TiO2/sepiolite. SEM micrographs revealed that Ag@AgCl nanoparticles and TiO2 film are well deposited on the surface of tube-like sepiolite. As a result, Ag@AgCl-TiO2/sepiolite exhibits a red shift relative to TiO2/sepiolite. Photocatalytic experiments demonstrated that the dosage of catalysts plays an important role during photocatalysis. The photoelectrochemical activities of Ag@AgCl-TiO2/sepiolite and TiO2/sepiolite were also investigated. Photocurrent responses confirmed that the ability of Ag@AgCl-TiO2/sepiolite to separate photo-generated electron-hole pairs is stronger than that of TiO2/sepiolite. Methylene Blue degradation is also improved under alkaline conditions and visible light irradiation because more OH is produced by visible light excitation. This excellent catalytic ability is mainly attributed to the formed Ag nanoparticles and the Schottky barrier at the Ag/TiO2 interface. Active species analysis indicated that O2- and h+ are implicated as active species in photocatalysis. Therefore, catalysts are excited to produce abundant electron-hole pairs after they absorb photons in photocatalysis.
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Affiliation(s)
- Shaomin Liu
- School of Earth Science and Environmental Engineering, Anhui University of Science and Technology, Huainan 232001, China.
| | - Dinglong Zhu
- School of Earth Science and Environmental Engineering, Anhui University of Science and Technology, Huainan 232001, China
| | - Jinglin Zhu
- School of Earth Science and Environmental Engineering, Anhui University of Science and Technology, Huainan 232001, China
| | - Qing Yang
- School of Earth Science and Environmental Engineering, Anhui University of Science and Technology, Huainan 232001, China
| | - Huijun Wu
- School of Earth Science and Environmental Engineering, Anhui University of Science and Technology, Huainan 232001, China
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