1
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Qi K, Imparato C, Almjasheva O, Khataee A, Zheng W. TiO 2-based photocatalysts from type-II to S-scheme heterojunction and their applications. J Colloid Interface Sci 2024; 675:150-191. [PMID: 38968635 DOI: 10.1016/j.jcis.2024.06.204] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2024] [Revised: 06/23/2024] [Accepted: 06/26/2024] [Indexed: 07/07/2024]
Abstract
Photocatalysis is a promising sustainable technology to remove organic pollution and convert solar energy into chemical energy. Titanium dioxide has drawn extensive attention in this field owing to its high activity under UV light, good chemical stability, large availability, low price and low toxicity. However, the poor quantum efficiency derived from fast electron/hole recombination, the limited utilization of sunlight, and a weak reducing ability still hinder its practical application. Among the modification strategies of TiO2 to enhance its performance, the construction of heterojunctions with other semiconductors is a powerful and versatile way to maximise the separation of photogenerated charge carriers and steer their transport toward enhanced efficiency and selectivity. Here, the research progress and current status of TiO2 modification are reviewed, focusing on heterojunctions. A rapid evolution of the understanding of the different charge transfer mechanisms is witnessed from traditional type II to the recently conceptualised S-scheme. Particular attention is paid to different synthetic approaches and interface engineering methods designed to improve and control the interfacial charge transfer, and several cases of TiO2 heterostructures with metal oxides, metal sulfides and carbon nitride are discussed. The application hotspots of TiO2-based photocatalysts are summarized, including hydrogen generation by water splitting, solar fuel production by CO2 conversion, and the degradation of organic water pollutants. Hints about less studied and emerging processes are also provided. Finally, the main issues and challenges related to the sustainability and scalability of photocatalytic technologies in view of their commercialization are highlighted, outlining future directions of development.
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Affiliation(s)
- Kezhen Qi
- College of Pharmacy, Dali University, Dali 671000, Yunnan, China
| | - Claudio Imparato
- Department of Chemical, Materials and Production Engineering, University of Naples Federico II, 80125 Naples, Italy.
| | - Oksana Almjasheva
- Department of Physical Chemistry, Saint Petersburg Electrotechnical University "LETI", Saint Petersburg, 197022, Russia
| | - Alireza Khataee
- Department of Chemical Engineering, Istanbul Technical University, 34469 Istanbul, Turkey; Peoples' Friendship University of Russia (RUDN University), 6 Miklukho-Maklaya Street, Moscow, 117198, Russian Federation.
| | - Wenjun Zheng
- College of Chemistry, Nankai University, Tianjin 300071, Tianjin, China.
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2
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Lakhdar R, Freyria FS, Mousdis GA, Bonelli B, Elghniji K. Salicylic Acid-Modified Sm-TiO 2 for Photoluminescence and Photocatalysis under Real Sunlight: Synergistic Effects between Ligand-to-Metal Charge Transfer (LMCT) and Sm 3+ Dopant. THE JOURNAL OF PHYSICAL CHEMISTRY. C, NANOMATERIALS AND INTERFACES 2024; 128:13445-13457. [PMID: 39165482 PMCID: PMC11331523 DOI: 10.1021/acs.jpcc.4c03459] [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: 05/26/2024] [Revised: 07/13/2024] [Accepted: 07/15/2024] [Indexed: 08/22/2024]
Abstract
A salicylic-acid (SA)-modified samarium-doped TiO2 complex (Sm-TiO2/SA) was synthesized via a sol-gel method followed by impregnation. A Raman Fourier transform IR and X-ray photoelectron spectroscopic study showed that SA (as an electron donor) forms a surface complex on the Sm-TiO2 surface through its phenolic/carboxylic functional groups. In the Sm-TiO2/SA complex, a ligand-to-metal charge transfer (LMCT) is active, inducing a marked red-shift in the absorption spectrum of TiO2, which extends to 550-600 nm. The synergetic effect between the LMCT process and the luminescent properties of the lanthanide ions (Sm3+) is discussed and supported by the photoluminescence spectra. Further photocatalytic experiments (under sunlight) and the study of the effect of different scavengers show the presence of competitive reactions between de-ethylation and cleavage of Rhodamine B (RhB) during its degradation. With the Sm-TiO2/SA complexes, the superoxide radical ion (O2 •-) is the main active species responsible for the N-de-ethylation pathway under sunlight irradiation. The cleavage of RhB by the hydroxyl radical (•OH) appears, instead, to dominate with the Sm-TiO2 photocatalysts.
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Affiliation(s)
- Rostom Lakhdar
- Laboratory
of Materials Applications in Environment, Water and Energy LAMEEE
(LAM3E), Faculty of Sciences of Gafsa, University
of Gafsa, Sidi Ahmed Zarroug University Campus, Gafsa 2112, Tunisia
| | - Francesca S. Freyria
- Department
of Applied Science and Technology and INSTM-Unit of Torino Politecnico, Corso Duca degli Arbuzzi 24, Torino I-10129, Italy
| | - George A Mousdis
- Theoretical
and Physical Chemistry Institute, National
Hellenic Research Foundation, 48 Vasileos Constantinou Avenue, Athens 11635, Greece
| | - Barbara Bonelli
- Department
of Applied Science and Technology and INSTM-Unit of Torino Politecnico, Corso Duca degli Arbuzzi 24, Torino I-10129, Italy
- Interdepartmental
Centre PolitoBIOMed Lab, Corso Duca degli Arbuzzi 24, Torino I-10129, Italy
| | - Kais Elghniji
- Laboratory
of Materials Applications in Environment, Water and Energy LAMEEE
(LAM3E), Faculty of Sciences of Gafsa, University
of Gafsa, Sidi Ahmed Zarroug University Campus, Gafsa 2112, Tunisia
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3
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Marcelo G, Rodríguez-Pascual P, Batanero B, Mendicuti F, Pecharromán C. Sepiolite promotes photodegradation of pyrene under visible light. ECOTOXICOLOGY AND ENVIRONMENTAL SAFETY 2023; 266:115573. [PMID: 37856983 DOI: 10.1016/j.ecoenv.2023.115573] [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: 05/26/2023] [Revised: 10/06/2023] [Accepted: 10/09/2023] [Indexed: 10/21/2023]
Abstract
Mechanochemistry and photocatalysis are emergent technologies for the remediation of polycyclic aromatic hydrocarbons (PAHs) in soils. In this work, mechanochemistry and photocatalysis are combined for pyrene degradation. The photodegradation of pyrene, when in contact with sepiolite under pressure application, is studied. The mechanical treatment leads to a pyrene crystal phase transformation. In this new phase, pyrene undergoes a fast photodegradation in the 320-420 nm range. We show that sepiolite is superior as a photocatalyst in pyrene degradation to TiO2, the most exploited photocatalyst. A broad physicochemical characterization is carried out to propose a mechanism in which the photoexcitation of mechanically altered pyrene leads to an electron transfer to sepiolite matrix, which triggers the PAH degradation. Finally, we want to highlight that the pyrene/sepiolite combination is a simplified system to shed light on how PAH photodegradation may occur in soils.
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Affiliation(s)
- Gema Marcelo
- Universidad de Alcalá, Departamento de Química Analítica, Química Física e Ingeniería Química, Instituto de Investigación Química Andrés M. del Rio, Ctra. Madrid-Barcelona Km 33,600, Alcalá de Henares (Madrid) E-28805, Spain.
| | - Pedro Rodríguez-Pascual
- Instituto de Ciencia de los Materiales de Madrid (ICMM, CSIC), C/Sor Juana Inés de la Cruz 3, Madrid 28049, Spain
| | - Belen Batanero
- Universidad de Alcalá, Departamento de Química Orgánica y Química Inorgánica, Instituto de Investigación Química Andrés M. del Rio, Ctra. Madrid-Barcelona Km 33,600, Alcalá de Henares (Madrid) E-28805, Spain
| | - Francisco Mendicuti
- Universidad de Alcalá, Departamento de Química Analítica, Química Física e Ingeniería Química, Instituto de Investigación Química Andrés M. del Rio, Ctra. Madrid-Barcelona Km 33,600, Alcalá de Henares (Madrid) E-28805, Spain
| | - Carlos Pecharromán
- Instituto de Ciencia de los Materiales de Madrid (ICMM, CSIC), C/Sor Juana Inés de la Cruz 3, Madrid 28049, Spain.
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4
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Machín A, Cotto M, Ducongé J, Márquez F. Artificial Photosynthesis: Current Advancements and Future Prospects. Biomimetics (Basel) 2023; 8:298. [PMID: 37504186 PMCID: PMC10807655 DOI: 10.3390/biomimetics8030298] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2023] [Revised: 07/01/2023] [Accepted: 07/07/2023] [Indexed: 07/29/2023] Open
Abstract
Artificial photosynthesis is a technology with immense potential that aims to emulate the natural photosynthetic process. The process of natural photosynthesis involves the conversion of solar energy into chemical energy, which is stored in organic compounds. Catalysis is an essential aspect of artificial photosynthesis, as it facilitates the reactions that convert solar energy into chemical energy. In this review, we aim to provide an extensive overview of recent developments in the field of artificial photosynthesis by catalysis. We will discuss the various catalyst types used in artificial photosynthesis, including homogeneous catalysts, heterogeneous catalysts, and biocatalysts. Additionally, we will explore the different strategies employed to enhance the efficiency and selectivity of catalytic reactions, such as the utilization of nanomaterials, photoelectrochemical cells, and molecular engineering. Lastly, we will examine the challenges and opportunities of this technology as well as its potential applications in areas such as renewable energy, carbon capture and utilization, and sustainable agriculture. This review aims to provide a comprehensive and critical analysis of state-of-the-art methods in artificial photosynthesis by catalysis, as well as to identify key research directions for future advancements in this field.
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Affiliation(s)
- Abniel Machín
- Divisionof Natural Sciences and Technology, Universidad Ana G. Méndez-Cupey Campus, San Juan, PR 00926, USA
| | - María Cotto
- Nanomaterials Research Group, Department of Natural Sciences and Technology, Universidad Ana G. Méndez-Gurabo Campus, Gurabo, PR 00778, USA; (M.C.); (J.D.)
| | - José Ducongé
- Nanomaterials Research Group, Department of Natural Sciences and Technology, Universidad Ana G. Méndez-Gurabo Campus, Gurabo, PR 00778, USA; (M.C.); (J.D.)
| | - Francisco Márquez
- Nanomaterials Research Group, Department of Natural Sciences and Technology, Universidad Ana G. Méndez-Gurabo Campus, Gurabo, PR 00778, USA; (M.C.); (J.D.)
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5
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Mančić L, Almeida LA, Machado TM, Gil-Londoño J, Dinić I, Tomić M, Marković S, Jardim P, Marinkovic BA. Tetracycline Removal through the Synergy of Catalysis and Photocatalysis by Novel NaYF 4:Yb,Tm@TiO 2-Acetylacetone Hybrid Core-Shell Structures. Int J Mol Sci 2023; 24:ijms24119441. [PMID: 37298390 DOI: 10.3390/ijms24119441] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2023] [Revised: 05/22/2023] [Accepted: 05/23/2023] [Indexed: 06/12/2023] Open
Abstract
Novel hybrid core-shell structures, in which up-converting (UC) NaYF4:Yb,Tm core converts near-infrared (NIR) to visible (Vis) light via multiphoton up-conversion processes, while anatase TiO2-acetylacetonate (TiO2-Acac) shell ensures absorption of the Vis light through direct injection of excited electrons from the highest-occupied-molecular-orbital (HOMO) of Acac into the TiO2 conduction band (CB), were successfully synthesized by a two-step wet chemical route. Synthesized NaYF4:Yb,Tm@TiO2-Acac powders were characterized by X-ray powder diffraction, thermogravimetric analysis, scanning and transmission electron microscopy, diffuse-reflectance spectroscopy, Fourier transform infrared spectroscopy, and photoluminescence emission measurement. Tetracycline, as a model drug, was used to investigate the photocatalytic efficiencies of the core-shell structures under irradiation of reduced power Vis and NIR spectra. It was shown that the removal of tetracycline is accompanied by the formation of intermediates, which formed immediately after bringing the drug into contact with the novel hybrid core-shell structures. As a result, ~80% of tetracycline is removed from the solution after 6 h.
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Affiliation(s)
- Lidija Mančić
- Institute of Technical Sciences of SASA, 11000 Belgrade, Serbia
| | - Lucas A Almeida
- Department of Chemical and Materials Engineering, Pontifical Catholic University of Rio de Janeiro (PUC-Rio), Rio de Janeiro 22453-900, Brazil
| | - Tamires M Machado
- Department of Chemical and Materials Engineering, Pontifical Catholic University of Rio de Janeiro (PUC-Rio), Rio de Janeiro 22453-900, Brazil
| | - Jessica Gil-Londoño
- Department of Chemical and Materials Engineering, Pontifical Catholic University of Rio de Janeiro (PUC-Rio), Rio de Janeiro 22453-900, Brazil
| | - Ivana Dinić
- Institute of Technical Sciences of SASA, 11000 Belgrade, Serbia
| | - Miloš Tomić
- Institute of Technical Sciences of SASA, 11000 Belgrade, Serbia
| | - Smilja Marković
- Institute of Technical Sciences of SASA, 11000 Belgrade, Serbia
| | - Paula Jardim
- Department of Metallurgical and Materials Engineering, Federal University of Rio de Janeiro, Rio de Janeiro 21941-853, Brazil
| | - Bojan A Marinkovic
- Department of Chemical and Materials Engineering, Pontifical Catholic University of Rio de Janeiro (PUC-Rio), Rio de Janeiro 22453-900, Brazil
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6
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Copper indium sulfide quantum dots in photocatalysis. J Colloid Interface Sci 2023; 638:193-219. [PMID: 36738544 DOI: 10.1016/j.jcis.2023.01.107] [Citation(s) in RCA: 16] [Impact Index Per Article: 16.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2022] [Revised: 01/17/2023] [Accepted: 01/22/2023] [Indexed: 01/27/2023]
Abstract
Since the advent of photocatalytic technology, scientists have been searching for semiconductor materials with high efficiency in solar energy utilization and conversion to chemical energy. Recently, the development of quantum dot (QD) photocatalysts has attracted much attention because of their unique characteristics: small size, quantum effects, strong surface activity, and wide photoresponse range. Among ternary chalcogenide semiconductors, CuInS2 QDs are increasingly examined in the field of photocatalysis due to their high absorption coefficients, good matching of the absorption range with sunlight spectrum, long lifetimes of photogenerated electron-hole pairs and environmental sustainability. In this review paper, the structural and electronic properties, synthesis methods and various photocatalytic applications of CuInS2 QDs are systematically expounded. The current research status on the photocatalytic properties of materials based on CuInS2 QD is discussed combined with the existing modification approaches for the enhancement of their performances. Future challenges and new development opportunities of CuInS2 QDs in the field of photocatalysis are then prospected.
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7
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Clarizia L, Vitiello G, Bericat Vadell R, Sá J, Marotta R, Di Somma I, Andreozzi R, Luciani G. Effect of Synthesis Method on Reaction Mechanism for Hydrogen Evolution over Cu xO y/TiO 2 Photocatalysts: A Kinetic Analysis. Int J Mol Sci 2023; 24:2004. [PMID: 36768327 PMCID: PMC9916258 DOI: 10.3390/ijms24032004] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2022] [Revised: 01/12/2023] [Accepted: 01/16/2023] [Indexed: 01/21/2023] Open
Abstract
The existing literature survey reports rare and conflicting studies on the effect of the preparation method of metal-based semiconductor photocatalysts on structural/morphological features, electronic properties, and kinetics regulating the photocatalytic H2 generation reaction. In this investigation, we compare the different copper/titania-based photocatalysts for H2 generation synthesized via distinct methods (i.e., photodeposition and impregnation). Our study aims to establish a stringent correlation between physicochemical/electronic properties and photocatalytic performances for H2 generation based on material characterization and kinetic modeling of the experimental outcomes. Estimating unknown kinetic parameters, such as charge recombination rate and quantum yield, suggests a mechanism regulating charge carrier lifetime depending on copper distribution on the TiO2 surface. We demonstrate that H2 generation photoefficiency recorded over impregnated CuxOy/TiO2 is related to an even distribution of Cu(0)/Cu(I) on TiO2, and the formation of an Ohmic junction concertedly extended charge carrier lifetime and separation. The outcomes of the kinetic analysis and the related modeling investigation underpin photocatalyst physicochemical and electronic properties. Overall, the present study lays the groundwork for the future design of metal-based semiconductor photocatalysts with high photoefficiencies for H2 evolution.
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Affiliation(s)
- Laura Clarizia
- Department of Chemical, Materials and Industrial Production Engineering, University of Naples “Federico II”, p.le V. Tecchio 80, 80125 Napoli, Italy
| | - Giuseppe Vitiello
- Department of Chemical, Materials and Industrial Production Engineering, University of Naples “Federico II”, p.le V. Tecchio 80, 80125 Napoli, Italy
- CSGI, Center for Colloid and Interface Science, via della Lastruccia 3, 50019 Sesto Fiorentino, Italy
| | - Robert Bericat Vadell
- Department of Chemistry-Ångström, Physical Chemistry Division, Uppsala University, P.O. Box 532, 751 20 Uppsala, Sweden
| | - Jacinto Sá
- Department of Chemistry-Ångström, Physical Chemistry Division, Uppsala University, P.O. Box 532, 751 20 Uppsala, Sweden
- Institute of Physical Chemistry, Polish Academy of Sciences, Kasprzaka 44/52, 01-224 Warsaw, Poland
| | - Raffaele Marotta
- Department of Chemical, Materials and Industrial Production Engineering, University of Naples “Federico II”, p.le V. Tecchio 80, 80125 Napoli, Italy
| | - Ilaria Di Somma
- Istituto di Scienze e Tecnologie per l’Energia e la Mobilità Sostenibili (STEMS)-Consiglio Nazionale delle Ricerche, p.le V. Tecchio 80, 80125 Napoli, Italy
| | - Roberto Andreozzi
- Department of Chemical, Materials and Industrial Production Engineering, University of Naples “Federico II”, p.le V. Tecchio 80, 80125 Napoli, Italy
| | - Giuseppina Luciani
- Department of Chemical, Materials and Industrial Production Engineering, University of Naples “Federico II”, p.le V. Tecchio 80, 80125 Napoli, Italy
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8
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Navalón S, Dhakshinamoorthy A, Álvaro M, Ferrer B, García H. Metal-Organic Frameworks as Photocatalysts for Solar-Driven Overall Water Splitting. Chem Rev 2022; 123:445-490. [PMID: 36503233 PMCID: PMC9837824 DOI: 10.1021/acs.chemrev.2c00460] [Citation(s) in RCA: 60] [Impact Index Per Article: 30.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
Metal-organic frameworks (MOFs) have been frequently used as photocatalysts for the hydrogen evolution reaction (HER) using sacrificial agents with UV-vis or visible light irradiation. The aim of the present review is to summarize the use of MOFs as solar-driven photocatalysts targeting to overcome the current efficiency limitations in overall water splitting (OWS). Initially, the fundamentals of the photocatalytic OWS under solar irradiation are presented. Then, the different strategies that can be implemented on MOFs to adapt them for solar photocatalysis for OWS are discussed in detail. Later, the most active MOFs reported until now for the solar-driven HER and/or oxygen evolution reaction (OER) are critically commented. These studies are taken as precedents for the discussion of the existing studies on the use of MOFs as photocatalysts for the OWS under visible or sunlight irradiation. The requirements to be met to use MOFs at large scale for the solar-driven OWS are also discussed. The last section of this review provides a summary of the current state of the field and comments on future prospects that could bring MOFs closer to commercial application.
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Affiliation(s)
- Sergio Navalón
- Departamento
de Química, Universitat Politècnica
de València, Camino de Vera s/n, Valencia46022, Spain,S.N.: email,
| | - Amarajothi Dhakshinamoorthy
- Departamento
de Química, Universitat Politècnica
de València, Camino de Vera s/n, Valencia46022, Spain,School
of Chemistry, Madurai Kamaraj University, Palkalai Nagar, Madurai625021, Tamil
NaduIndia,A.D.: email,
| | - Mercedes Álvaro
- Departamento
de Química, Universitat Politècnica
de València, Camino de Vera s/n, Valencia46022, Spain
| | - Belén Ferrer
- Departamento
de Química, Universitat Politècnica
de València, Camino de Vera s/n, Valencia46022, Spain
| | - Hermenegildo García
- Departamento
de Química, Universitat Politècnica
de València, Camino de Vera s/n, Valencia46022, Spain,Instituto
Universitario de Tecnología Química, CSIC-UPV, Universitat Politècnica de València, Avenida de los Naranjos, Valencia46022, Spain,H.G.:
email,
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9
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Recent Developments in Heterogeneous Photocatalysts with Near-Infrared Response. Symmetry (Basel) 2022. [DOI: 10.3390/sym14102107] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Abstract
Photocatalytic technology has been considered as an efficient protocol to drive chemical reactions in a sustainable and green way. With the assistance of semiconductor-based materials, heterogeneous photocatalysis converts solar energy directly into chemical energy that can be readily stored. It has been employed in several fields including CO2 reduction, H2O splitting, and organic synthesis. Given that near-infrared (NIR) light occupies 47% of sunlight, photocatalytic systems with a NIR response are gaining more and more attention. To enhance the solar-to-chemical conversion efficiency, precise regulation of the symmetric/asymmetric nanostructures and band structures of NIR-response photocatalysts is indispensable. Under the irradiation of NIR light, the symmetric nano-morphologies (e.g., rod-like core-shell shape), asymmetric electronic structures (e.g., defect levels in band gap) and asymmetric heterojunctions (e.g., PN junctions, semiconductor-metal or semiconductor-dye composites) of designed photocatalytic systems play key roles in promoting the light absorption, the separation of electron/hole pairs, the transport of charge carriers to the surface, or the rate of surface photocatalytic reactions. This review will comprehensively analyze the four main synthesis protocols for the fabrication of NIR-response photocatalysts with improved reaction performance. The design methods involve bandgap engineering for the direct utilization of NIR photoenergy, the up-conversion of NIR light into ultraviolet/visible light, and the photothermal effect by converting NIR photons into local heat. Additionally, challenges and perspectives for the further development of heterogeneous photocatalysts with NIR response are also discussed based on their potential applications.
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10
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Siddique F, Gonzalez-Cortes S, Mirzaei A, Xiao T, Rafiq MA, Zhang X. Solution combustion synthesis: the relevant metrics for producing advanced and nanostructured photocatalysts. NANOSCALE 2022; 14:11806-11868. [PMID: 35920714 DOI: 10.1039/d2nr02714c] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/15/2023]
Abstract
The current developments and progress in energy and environment-related areas pay special attention to the fabrication of advanced nanomaterials via green and sustainable paths to accomplish chemical circularity. The design and preparation methods of photocatalysts play a prime role in determining the structural, surface characteristics and optoelectronic properties of the final products. The solution combustion synthesis (SCS) technique is a relatively novel, cost-effective, and efficient method for the bulk production of nanostructured materials. SCS-fabricated metal oxides are of great technological importance in photocatalytic, environmental and energy applications. To date, the SCS route has been employed to produce a large variety of solid materials such as metals, sulfides, carbides, nitrides and single or complex metal oxides. This review intends to provide a holistic perspective of the different steps involved in the chemistry of SCS of advanced photocatalysts, and pursues several SCS metrics that influence their photocatalytic performances to establish a feasible approach to design advanced photocatalysts. The study highlights the fundamentals of SCS and the importance of various combustion parameters in the characteristics of the fabricated photocatalysts. Consequently, this work deals with the design of a concise framework to link the fine adjustment of SCS parameters for the development of efficient metal oxide photocatalysts for energy and environmental applications.
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Affiliation(s)
- Fizza Siddique
- School of Science, Minzu University of China, Beijing, 100081, People's Republic of China.
- Department of Physics and Applied Mathematics, Pakistan Institute of Engineering and Applied Sciences, Nilore, Islamabad 45650, Pakistan
| | - Sergio Gonzalez-Cortes
- Inorganic Chemistry Laboratory, Department of Chemistry, University of Oxford, South Parks Road, Oxford OX1 3QR, UK.
| | - Amir Mirzaei
- Institut National de la Recherche Scientifique, Centre Énergie, Matériaux et Télécommunications, 1650 Boulevard Lionel-Boulet, Varennes, Québec J3X 1P7, Canada
| | - Tiancun Xiao
- Inorganic Chemistry Laboratory, Department of Chemistry, University of Oxford, South Parks Road, Oxford OX1 3QR, UK.
| | - M A Rafiq
- Department of Physics and Applied Mathematics, Pakistan Institute of Engineering and Applied Sciences, Nilore, Islamabad 45650, Pakistan
| | - Xiaoming Zhang
- School of Science, Minzu University of China, Beijing, 100081, People's Republic of China.
- Optoelectronics Research Center, Minzu University of China, Beijing, 100081, People's Republic of China
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11
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Wang Z, Hu Y, Zhang S, Sun Y. Artificial photosynthesis systems for solar energy conversion and storage: platforms and their realities. Chem Soc Rev 2022; 51:6704-6737. [PMID: 35815740 DOI: 10.1039/d1cs01008e] [Citation(s) in RCA: 26] [Impact Index Per Article: 13.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
In natural photosynthesis, photosynthetic organisms such as green plants realize efficient solar energy conversion and storage by integrating photosynthetic components on the thylakoid membrane of chloroplasts. Inspired by natural photosynthesis, researchers have developed many artificial photosynthesis systems (APS's) that integrate various photocatalysts and biocatalysts to convert and store solar energy in the fields of resource, environment, food, and energy. To improve the system efficiency and reduce the operation cost, reaction platforms are introduced in APS's since they allow for great stability and continuous processing. A systematic understanding of how a reaction platform affects the performance of artificial photosynthesis is conducive for designing an APS with superb solar energy utilization. In this review, we discuss the recent APS's researches, especially those confined on/in platforms. The importance of different platforms and their influences on APS's performance are emphasized. Generally, confined platforms can enhance the stability and repeatability of both photocatalysts and biocatalysts in APS's as well as improve the photosynthetic performance due to the proximity effect. For functional platforms that can participate in the artificial photosynthesis reactions as active parts, a high integration of APS's components on/in these platforms can lead to efficient electron transfer, enhanced light-harvesting, or synergistic catalysis, resulting in superior photosynthesis performance. Therefore, the integration of APS's components is beneficial for the transfer of substrates and photoexcited electrons in artificial photosynthesis. We finally summarize the current challenges of APS's development and further efforts on the improvement of APS's.
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Affiliation(s)
- Zhenfu Wang
- Department of Biochemical Engineering, School of Chemical Engineering and Technology and Key Laboratory of Systems Bioengineering and Frontiers Science Center for Synthetic Biology (Ministry of Education), Tianjin University, Tianjin 300350, China.
| | - Yang Hu
- Department of Biochemical Engineering, School of Chemical Engineering and Technology and Key Laboratory of Systems Bioengineering and Frontiers Science Center for Synthetic Biology (Ministry of Education), Tianjin University, Tianjin 300350, China.
| | - Songping Zhang
- State Key Laboratory of Biochemical Engineering, Institute of Process Engineering, Chinese Academy of Sciences, Beijing, 100190, China
| | - Yan Sun
- Department of Biochemical Engineering, School of Chemical Engineering and Technology and Key Laboratory of Systems Bioengineering and Frontiers Science Center for Synthetic Biology (Ministry of Education), Tianjin University, Tianjin 300350, China.
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12
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Hasnan NSN, Mohamed MA, Anuar NA, Abdul Sukur MF, Mohd Yusoff SF, Wan Mokhtar WNA, Mohd Hir ZA, Mohd Shohaimi NA, Ahmad Rafaie H. Emerging polymeric-based material with photocatalytic functionality for sustainable technologies. J IND ENG CHEM 2022. [DOI: 10.1016/j.jiec.2022.06.009] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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Recent Advances in Endocrine Disrupting Compounds Degradation through Metal Oxide-Based Nanomaterials. Catalysts 2022. [DOI: 10.3390/catal12030289] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023] Open
Abstract
Endocrine Disrupting Compounds (EDCs) comprise a class of natural or synthetic molecules and groups of substances which are considered as emerging contaminants due to their toxicity and danger for the ecosystems, including human health. Nowadays, the presence of EDCs in water and wastewater has become a global problem, which is challenging the scientific community to address the development and application of effective strategies for their removal from the environment. Particularly, catalytic and photocatalytic degradation processes employing nanostructured materials based on metal oxides, mainly acting through the generation of reactive oxygen species, are widely explored to eradicate EDCs from water. In this review, we report the recent advances described by the major publications in recent years and focused on the degradation processes of several classes of EDCs, such as plastic components and additives, agricultural chemicals, pharmaceuticals, and personal care products, which were realized by using novel metal oxide-based nanomaterials. A variety of doped, hybrid, composite and heterostructured semiconductors were reported, whose performances are influenced by their chemical, structural as well as morphological features. Along with photocatalysis, alternative heterogeneous advanced oxidation processes are in development, and their combination may be a promising way toward industrial scale application.
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Jing F, Guo Y, Li B, Chen YF, Jia C, Li J. Enhanced photocatalytic hydrogen production under visible light of an organic-inorganic hybrid material based on enzo[1,2-b:4,5-b']dithiophene polymer and TiO2. CHINESE CHEM LETT 2022. [DOI: 10.1016/j.cclet.2021.07.056] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
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Hydrogenated Amorphous Titania with Engineered Surface Oxygen Vacancy for Efficient Formaldehyde and Dye Removals under Visible-Light Irradiation. NANOMATERIALS 2022; 12:nano12050742. [PMID: 35269228 PMCID: PMC8911576 DOI: 10.3390/nano12050742] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 01/05/2022] [Revised: 02/11/2022] [Accepted: 02/16/2022] [Indexed: 01/19/2023]
Abstract
Hydrogenated crystalized TiO2−x with oxygen vacant (OV) doping has attracted considerable attraction, owing to its impressive photoactivity. However, amorphous TiO2, as a common allotrope of titania, is ignored as a hydrogenated templet. In this work, hydrogenated amorphous TiO2−x (HAm-TiO2−x) with engineered surface OV and high surface area (176.7 cm2 g−1) was first prepared using a unique liquid plasma hydrogenation strategy. In HAm-TiO2−x, we found that OV was energetically retained in the subsurface region; in particular, the subsurface OV-induced energy level preferred to remain under the conduction band (0.5 eV) to form a conduction band tail and deep trap states, resulting in a narrow bandgap (2.36 eV). With the benefits of abundant light absorption and efficient photocarrier transportation, HAm-TiO2−x coated glass has demonstrated superior visible-light-driven self-cleaning performances. To investigate its formaldehyde photodegradation under harsh indoor conditions, HAm-TiO2−x was used to decompose low-concentration formaldehyde (~0.6 ppm) with weak-visible light (λ = 600 nm, power density = 0.136 mW/cm2). Thus, HAm-TiO2−x achieved high quantum efficiency of 3 × 10−6 molecules/photon and photoactivity of 92.6%. The adsorption capabilities of O2 (−1.42 eV) and HCHO (−1.58 eV) in HAm-TiO2−x are both largely promoted in the presence of subsurface OV. The surface reaction pathway and formaldehyde decomposition mechanism over HAm-TiO2−x were finally clarified. This work opened a promising way to fabricate hydrogenated amorphous photocatalysts, which could contribute to visible-light-driven photocatalytic environmental applications.
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Imparato C, D’Errico G, Macyk W, Kobielusz M, Vitiello G, Aronne A. Interfacial Charge Transfer Complexes in TiO 2-Enediol Hybrids Synthesized by Sol-Gel. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2022; 38:1821-1832. [PMID: 35090125 PMCID: PMC8830207 DOI: 10.1021/acs.langmuir.1c02939] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 11/03/2021] [Revised: 01/14/2022] [Indexed: 06/14/2023]
Abstract
Metal oxide-organic hybrid semiconductors exhibit specific properties depending not only on their composition but also on the synthesis procedure, and particularly on the functionalization method, determining the interaction between the two components. Surface adsorption is the most common way to prepare organic-modified metal oxides. Here a simple sol-gel route is described as an alternative, finely controlled strategy to synthesize titanium oxide-based materials containing organic molecules coordinated to the metal. The effect of the molecular structure of the ligands on the surface properties of the hybrids is studied using three enediols able to form charge transfer complexes: catechol, dopamine, and ascorbic acid. For each system, the process conditions driving the transition from the sol to chemical, physical, or particulate gels are explored. The structural, optical, and photoelectrochemical characterization of the amorphous hybrid materials shows analogies and differences related to the organic component. In particular, electron paramagnetic resonance (EPR) spectroscopy at room temperature reveals the presence of organic radical species with different evolution and stability, and photocurrent measurements prove the effective photosensitization of TiO2 in the visible range induced by interfacial ligand-to-metal charge transfer.
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Affiliation(s)
- Claudio Imparato
- Department
of Chemical, Materials and Production Engineering, University of Naples Federico II, P.le V. Tecchio 80, 80125 Napoli, Italy
| | - Gerardino D’Errico
- Department
of Chemical Sciences, University of Naples
Federico II, Via Cinthia, 80126 Napoli, Italy
| | - Wojciech Macyk
- Faculty
of Chemistry, Jagiellonian University, ul. Gronostajowa 2, Kraków 30-387, Poland
| | - Marcin Kobielusz
- Faculty
of Chemistry, Jagiellonian University, ul. Gronostajowa 2, Kraków 30-387, Poland
| | - Giuseppe Vitiello
- Department
of Chemical, Materials and Production Engineering, University of Naples Federico II, P.le V. Tecchio 80, 80125 Napoli, Italy
| | - Antonio Aronne
- Department
of Chemical, Materials and Production Engineering, University of Naples Federico II, P.le V. Tecchio 80, 80125 Napoli, Italy
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Demir M, Taymaz BH, Sarıbel M, Kamış H. Photocatalytic Degradation of Organic Dyes with Magnetically Separable PANI/Fe
3
O
4
Composite under Both UV and Visible‐light Irradiation. ChemistrySelect 2022. [DOI: 10.1002/slct.202103787] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Affiliation(s)
- Muslum Demir
- Department of Chemical Engineering Osmaniye Korkut Ata University Osmaniye 80000 Turkey
| | - Bircan Haspulat Taymaz
- Department of Chemical Engineering Konya Technical University Selçuklu 42200 Konya Turkey
| | - Muhammet Sarıbel
- Department of Chemical Engineering Konya Technical University Selçuklu 42200 Konya Turkey
| | - Handan Kamış
- Department of Chemical Engineering Konya Technical University Selçuklu 42200 Konya Turkey
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TiO2-Acetylacetone as an Efficient Source of Superoxide Radicals under Reduced Power Visible Light: Photocatalytic Degradation of Chlorophenol and Tetracycline. Catalysts 2022. [DOI: 10.3390/catal12020116] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/04/2022] Open
Abstract
Visible light-sensitive TiO2-based nanomaterials are widely investigated for photocatalytic applications under high power (≥300 W) UV and visible light. The formation of charge transfer complexes (CTCs) between bidentate ligands and nanocrystalline TiO2 promotes visible light absorption and constitutes a promising alternative for environmental remediation under reduced visible light power. However, the efficiency of photodegradation, the volatilization profile of bidentates, and the role of reactive oxidizing species (ROS) are not fully understood. In this study, thermogravimetric analyses coupled with mass spectroscopy (TGA-MS) were performed on TiO2-Acetylacetone (ACAC) CTC. TiO2-ACAC CTC calcined at 300 °C (TiO2-A300) was applied for the photocatalytic degradation of chlorophenol (4-CP) and tetracycline (TC) under low power visible light (26 W). Furthermore, the ROS scavengers isopropanol and benzoquinone were added for studying the photocatalytic role of •OH and •O2− radicals. The TGA-MS showed the release of ACAC fragments, such as ethyl ions and acetone, in the range between 150 °C and 265 °C, while between 300 °C and 450 °C only CO2 and H2O were released during oxidation of ACAC. The photocatalytic abatement of tetracycline (68.6%), performed by TiO2-A300, was ~two times higher than that observed for chlorophenol (31.3%) after 6 h, indicating a distinct participation of ROS in the degradation of these pollutants. The addition of the ROS scavenger revealed •O2− radicals as primarily responsible for the high efficiency of TiO2-ACAC CTC under reduced visible light. On the other hand, the •OH radicals are not efficiently generated in the CTC. Therefore, the development of heterostructures based on TiO2-ACAC CTC can increase the generation of ROS through coupling with semiconductors capable of generating •OH under visible light.
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Capture and Reuse of Carbon Dioxide (CO2) for a Plastics Circular Economy: A Review. Processes (Basel) 2021. [DOI: 10.3390/pr9050759] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022] Open
Abstract
Plastic production has been increasing at enormous rates. Particularly, the socioenvironmental problems resulting from the linear economy model have been widely discussed, especially regarding plastic pieces intended for single use and disposed improperly in the environment. Nonetheless, greenhouse gas emissions caused by inappropriate disposal or recycling and by the many production stages have not been discussed thoroughly. Regarding the manufacturing processes, carbon dioxide is produced mainly through heating of process streams and intrinsic chemical transformations, explaining why first-generation petrochemical industries are among the top five most greenhouse gas (GHG)-polluting businesses. Consequently, the plastics market must pursue full integration with the circular economy approach, promoting the simultaneous recycling of plastic wastes and sequestration and reuse of CO2 through carbon capture and utilization (CCU) strategies, which can be employed for the manufacture of olefins (among other process streams) and reduction of fossil-fuel demands and environmental impacts. Considering the previous remarks, the present manuscript’s purpose is to provide a review regarding CO2 emissions, capture, and utilization in the plastics industry. A detailed bibliometric review of both the scientific and the patent literature available is presented, including the description of key players and critical discussions and suggestions about the main technologies. As shown throughout the text, the number of documents has grown steadily, illustrating the increasing importance of CCU strategies in the field of plastics manufacture.
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Green Synthesis of N/Zr Co-Doped TiO2 for Photocatalytic Degradation of p-Nitrophenol in Wastewater. Catalysts 2021. [DOI: 10.3390/catal11020235] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023] Open
Abstract
TiO2 prepared by a green aqueous sol–gel peptization process is co-doped with nitrogen and zirconium to improve and extend its photoactivity to the visible region. Two nitrogen precursors are used: urea and triethylamine; zirconium (IV) tert-butoxide is added as a source of zirconia. The N/Ti molar ratio is fixed regardless of the chosen nitrogen precursor while the quantity of zirconia is set to 0.7, 1.4, 2, or 2.8 mol%. The performance and physico-chemical properties of these materials are compared with the commercial Evonik P25 photocatalyst. For all doped and co-doped samples, TiO2 nanoparticles of 4 to 8 nm of size are formed of anatase-brookite phases, with a specific surface area between 125 and 280 m2 g−1 vs. 50 m2 g−1 for the commercial P25 photocatalyst. X-ray photoelectron (XPS) measurements show that nitrogen is incorporated into the TiO2 materials through Ti-O-N bonds allowing light absorption in the visible region. The XPS spectra of the Zr-(co)doped powders show the presence of TiO2-ZrO2 mixed oxide materials. Under visible light, the best co-doped sample gives a degradation of p-nitrophenol (PNP) equal to 70% instead of 25% with pure TiO2 and 10% with P25 under the same conditions. Similarly, the photocatalytic activity improved under UV/visible reaching 95% with the best sample compared to 50% with pure TiO2. This study suggests that N/Zr co-doped TiO2 nanoparticles can be produced in a safe and energy-efficient way while being markedly more active than state-of-the-art photocatalytic materials under visible light.
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Potapenko KO, Kurenkova AY, Bukhtiyarov AV, Gerasimov EY, Cherepanova SV, Kozlova EA. Comparative Study of the Photocatalytic Hydrogen Evolution over Cd 1-xMn xS and CdS-β-Mn 3O 4-MnOOH Photocatalysts under Visible Light. NANOMATERIALS 2021; 11:nano11020355. [PMID: 33535500 PMCID: PMC7912750 DOI: 10.3390/nano11020355] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 12/31/2020] [Revised: 01/22/2021] [Accepted: 01/27/2021] [Indexed: 02/07/2023]
Abstract
A series of solid solutions of cadmium and manganese sulfides, Cd1−xMnxS (x = 0–0.35), and composite photocatalysts, CdS-β-Mn3O4-MnOOH, were synthesized by precipitation with sodium sulfide from soluble cadmium and manganese salts with further hydrothermal treatment at 120 °C. The obtained photocatalysts were studied by the X-ray diffraction method (XRD), UV-vis diffuse reflectance spectroscopy, transmission electron microscopy (TEM), X-ray photoelectron spectroscopy (XPS), and N2 low temperature adsorption. The photocatalysts were tested in hydrogen production using a Na2S/Na2SO3 aqueous solution under visible light (λ = 450 nm). It was shown for the first time that both kinds of photocatalysts possess high activity in hydrogen evolution under visible light. The solid solution Cd0.65Mn0.35S has an enhanced photocatalytic activity due to its valence and conduction band position tuning, whereas the CdS-β-Mn3O4-MnOOH (40–60 at% Mn) samples were active due to ternary heterojunction formation. Further, the composite CdS-β-Mn3O4-MnOOH photocatalyst had much higher stability in comparison to the Cd0.65Mn0.35S solid solution. The highest activity was 600 mmol g−1 h−1, and apparent quantum efficiency of 2.9% (λ = 450 nm) was possessed by the sample of CdS-β-Mn3O4-MnOOH (40 at% Mn).
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Conventional and Current Methods of Toxic Metals Removal from Water Using g-C3N4-Based Materials. J Inorg Organomet Polym Mater 2020. [DOI: 10.1007/s10904-020-01803-3] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
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Recent Advances in Photocatalytic CO2 Utilisation Over Multifunctional Metal–Organic Frameworks. Catalysts 2020. [DOI: 10.3390/catal10101176] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022] Open
Abstract
The efficient conversion of carbon dioxide (CO2) to high-value chemicals using renewable solar energy is a highly attractive but very challenging process that is used to address ever-growing energy demands and environmental issues. In recent years, metal–organic frameworks (MOFs) have received significant research attention owing to their tuneability in terms of their composition, structure, and multifunctional characteristics. The functionalisation of MOFs by metal nanoparticles (NPs) is a promising approach used to enhance their light absorption and photocatalytic activity. The efficient charge separation and strong CO2 binding affinity of hybrid MOF-based photocatalysts facilitate the CO2 conversion process. This review summarises the latest advancements involving noble metal, non-noble-metal, and miscellaneous species functionalised MOF-based hybrid photocatalysts for the reduction of CO2 to carbon monoxide (CO) and other value-added chemicals. The novel synthetic strategies and their corresponding structure–property relationships have also been discussed for solar-to-chemical energy conversion. Furthermore, the current challenges and prospects in practical applications are also highlighted for sustainable energy production.
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i-Propylammonium Lead Chloride Based Perovskite Photocatalysts for Depolymerization of Lignin Under UV Light. Molecules 2020; 25:molecules25153520. [PMID: 32752133 PMCID: PMC7435779 DOI: 10.3390/molecules25153520] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2020] [Revised: 06/16/2020] [Accepted: 06/22/2020] [Indexed: 01/14/2023] Open
Abstract
Lignin depolymerization for the purpose of synthesizing aromatic molecules is a growing focus of research to find alternative energy sources. In current studies, the photocatalytic depolymerization of lignin has been investigated by two new iso-propylamine-based lead chloride perovskite nanomaterials (SK9 and SK10), synthesized by the facile hydrothermal method. Characterization was done by Powder X-Ray Diffraction (PXRD), Scanning Electron Microscopy (SEM), UV-Visible (UV-Vis), Photoluminescence (PL), and Fourier-Transform Infrared (FTIR) Spectroscopy and was used for the photocatalytic depolymerization of lignin under UV light. Lignin depolymerization was monitored by taking absorption spectra and catalytic paths studied by applying kinetic models. The %depolymerization was calculated for factors such as catalyst dose variation, initial concentration of lignin, and varying temperatures. Pseudo-second order was the best suited kinetic model, exhibiting a mechanism for lignin depolymerization that was chemically rate controlled. The activation energy (Ea) for the depolymerization reaction was found to be 15 kJ/mol, which is remarkably less than conventional depolymerization of the lignin, i.e., 59.75 kJ/mol, exhibiting significant catalytic efficiencies of synthesized perovskites. Products of lignin depolymerization obtained after photocatalytic activity at room temperature (20 °C) and at 90 °C were characterized by GC-MS analysis, indicating an increase in catalytic lignin depolymerization structural subunits into small monomeric functionalities at higher temperatures. Specifically, 2-methoxy-4-methylphenol (39%), benzene (17%), phenol (10%) and catechol (7%) were detected by GC-MS analysis of lignin depolymerization products.
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Abstract
In recent years, much attention was focused on developing green materials and fillers for polymer composites. This work is about the development of such green nanofiller for reinforcement in epoxy polymer matrix. A cellulose nanofiber (CNF)-filled epoxy polymer nanocomposites was prepared in this work. The effect of CNF on curing, thermal, mechanical, and barrier properties of epoxy polymer is evaluated in this study. CNF were extracted from banana fiber using acid hydrolysis method and then filled in epoxy polymer at various concentration (0–5 wt.%) to form CNF-filled epoxy nanocomposites. The structure and morphology of the CNF-filled epoxy nanocomposites were examined by scanning electron microscopy (SEM) and transmission electron microscopy (TEM) analysis. Curing studies shows CNF particles acts as a catalytic curing agent with increased cross-link density. This catalytic effect of CNF particles has positively affected tensile, thermal (thermogravimetry analysis and dynamic mechanical analysis) and water barrier properties. Water uptake test of nanocomposites was studied to understand the barrier properties. Overall result also shows that the CNF can be a potential green nanofiller for thermoset epoxy polymer with promising applications ahead.
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Microwave-Assisted Solvothermal Synthesis of Chalcogenide Composite Photocatalyst and Its Photocatalytic CO2 Reduction Activity under Simulated Solar Light. Catalysts 2020. [DOI: 10.3390/catal10070789] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Abstract
A novel heterostructure consisting of Ru and Cu co-doped ZnS nanopowders (RCZS) into a MoS2-graphene hybrid (MSG) is successfully prepared by the microwave-assisted solvothermal approach. RCZS nanopowders are fabricated on the surface of MSG, which produces a nanoscale interfacial between RCZS and MSG. As the photo-excited electrons of RCZS can easily migrate to MoS2 through graphene by hindering the electron and hole (e– and h+) recombination, the photocatalytic activity could be improved by effective charge transfer. As RCZS are anchored onto the MSG, the photoluminescence intensity of the chalcogenide composite photocatalyst obviously decreases. In addition, a quaternary ruthenium and copper-based chalcogenide RCZS/MSG is able to improve the harvest and utilization of light. With the increase in the concentrations of Ru until 4 mol%, the band gap significantly decreases from 3.52 to 2.73 eV. At the same time, moderate modification by ruthenium can decrease the PL intensity compared to the pristine CZS/MSG sample, which indicates the enhancement of e– and h+ separation by Ru addition. The photocatalytic activity of as-synthesized chalcogenide composite photocatalysts is evaluated by the photocatalytic carbon dioxide reduction. Optimized operation conditions for carbon dioxide reduction have been performed, including the concentration of NaOH solution, the amount of RCZS/MSG photocatalyst, and the content of co-doped ruthenium. The doping of ruthenium would efficiently improve the performance of the photocatalytic activity for carbon dioxide reduction. The optimal conditions, such as the concentration of 2 M NaOH and the 0.5RCZS/MSG dosage of 0.05 g L–1, provide the maximum methane gas yield of 58.6 μmol h−1 g–1.
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Intermolecular interaction between anthraquinone dyes and TEMPO mediator in dye-sensitized photocatalytic systems. JOURNAL OF PHOTOCHEMISTRY AND PHOTOBIOLOGY 2020. [DOI: 10.1016/j.jpap.2020.100003] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022] Open
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Synthesis of Magnetic Fe3O4/ZnWO4 and Fe3O4/ZnWO4/CeVO4 Nanoparticles: The Photocatalytic Effects on Organic Pollutants upon Irradiation with UV-Vis Light. Catalysts 2020. [DOI: 10.3390/catal10050494] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022] Open
Abstract
Magnetic Fe3O4/ZnWO4 and Fe3O4/ZnWO4/CeVO4 nanoparticles with different molar ratios of CeVO4 to other inorganic components were synthesized through co-precipitation with a sonochemical-assisted method. X-ray diffraction, energy dispersive X-ray spectroscopy, Fourier transform infrared spectroscopy, ultraviolet-visible diffuse reflectance spectroscopy, vibrating sample magnetometry, and scanning electron microscopy (SEM) methods were used for the physico–chemical characterization of the obtained nanoparticles. As shown in the SEM images, the average sizes of the Fe3O4/ZnWO4 and Fe3O4/ZnWO4/CeVO4 nanoparticles that formed aggregates were approximately 50–70 nm and 80–100 nm, respectively. The photocatalytic performance of these nanoparticles was examined by measuring methylene blue degradation under visible light (assisted by H2O2). The sample with a mass ratio of 1:2:1 (Fe3O4/ZnWO4/CeVO4, S4) exhibited optimal photocatalytic performance, and thus this sample was subsequently used for the photodegradation of different organic pollutants upon irradiation with ultraviolet (UV) and visible light. Approximately 90% and 70% degradation of methyl violet and methylene blue, respectively, was observed after visible light irradiation. Additionally, the mechanism of the photocatalytic reaction was investigated by measuring ˙OH release under UV light in a system with terephthalic acid and by measuring the release of ˙O2−, ˙OH, and hole scavengers.
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