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Recio-Poo M, Morales-García Á, Illas F, Bromley ST. Tuning electronic levels in photoactive hydroxylated titania nanosystems: combining the ligand dipole effect and quantum confinement. NANOSCALE 2024. [PMID: 38618709 DOI: 10.1039/d3nr06189b] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/16/2024]
Abstract
Reducing the size of titania (TiO2) to the nanoscale promotes the photoactive anatase phase for use in a range of applications from industrial catalysis to environment remediation. The nanoscale dimensions of these systems affect the magnitude of the electronic energy gap by quantum confinement. Upon interaction with aqueous environments or water vapour, the surfaces of these systems will also be hydroxylated to some degree. In turn, this affects the electronic energy levels due to the cumulative electrostatic effect of the dipolar hydroxyl (-OH) ligands (i.e. the ligand dipole effect). Using accurate density functional calculations, we investigate the combined effects of quantum confinement and the hydration-induced ligand dipole effect on a set of realistic titania nanosystems over a wide range of hydroxylation. Our detailed investigation reveals that, contrary to previous models, the ligand dipole effect does not-linearly depend on the ligand coverage due to the formation of inter-ligand OH⋯OH hydrogen bonds. To account for the resulting effects, we propose a refined model, which describes the ligand dipole effect more accurately in our systems. We show that both hydroxylation (by the ligand dipole effect) and size (by quantum confinement) have significant but distinct impacts on the electronic energy levels in nanotitania. As an example, we discuss how variations in these effects can be used to tune the highest unoccupied energy level in nanotitania for enhancing the efficiency of the hydrogen evolution reaction. Overall, we show that any specific energy shift can be achieved by a range of different combinations of nanosystem size and degree of hydroxylation, thus providing options for energy-level tuning while also allowing consideration of practical constraints (e.g. synthetic limitations, operating conditions) for photochemical applications.
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Affiliation(s)
- Miguel Recio-Poo
- Departament de Ciència de Materials i Química Física & Institut de Química Teòrica i Computacional (IQTCUB), Universitat de Barcelona, c/Martí i Franquès 1-11, 08028 Barcelona, Spain.
| | - Ángel Morales-García
- Departament de Ciència de Materials i Química Física & Institut de Química Teòrica i Computacional (IQTCUB), Universitat de Barcelona, c/Martí i Franquès 1-11, 08028 Barcelona, Spain.
| | - Francesc Illas
- Departament de Ciència de Materials i Química Física & Institut de Química Teòrica i Computacional (IQTCUB), Universitat de Barcelona, c/Martí i Franquès 1-11, 08028 Barcelona, Spain.
| | - Stefan T Bromley
- Departament de Ciència de Materials i Química Física & Institut de Química Teòrica i Computacional (IQTCUB), Universitat de Barcelona, c/Martí i Franquès 1-11, 08028 Barcelona, Spain.
- Institució Catalana de recerca i Estudis Avançats (ICREA), Passeig Lluis Companys 23, 08010 Barcelona, Spain
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Mao X, Hao C. Recent advances in the use of composite titanium dioxide nanomaterials in the food industry. J Food Sci 2024; 89:1310-1323. [PMID: 38343295 DOI: 10.1111/1750-3841.16968] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2023] [Revised: 11/08/2023] [Accepted: 01/18/2024] [Indexed: 03/12/2024]
Abstract
Titanium dioxide (TiO2 ) nanomaterials have attracted significant attention due to their good biocompatibility and potential for multifunctional applications. In the last few years, there has been growing interest in the use of TiO2 nanomaterials in the food industry. However, a systematic review of the synthesis methods, properties, and applications of TiO2 nanomaterials in the food industry is lacking. In this review, we provide a summary of the synthesis and properties of TiO2 nanomaterials and their composites, with a focus on their applications in the food industry. We also discuss the potential benefits and risks of using TiO2 nanomaterials in food applications. This review aims to promote food innovation and improve food quality and safety.
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Affiliation(s)
- Xixi Mao
- School of Marxism, Jiangnan University, Wuxi, Jiangsu, China
| | - Changlong Hao
- State Key Laboratory of Food Science and Resources, Jiangnan University, Wuxi, Jiangsu, China
- School of Food Science and Technology, Jiangnan University, Wuxi, Jiangsu, China
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3
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Rosales Medina PY, Avelar Muñoz F, Flores Sigala E, Rosales RG, Berumen Torres JA, Araiza Ibarra JDJ, Tototzintle Huitle H, Méndez García VH, Ortega Sigala JJ. Growth of Nanocolumnar TiO 2 Bilayer by Direct Current Reactive Magnetron Sputtering in Glancing-Angle Deposition Configuration for High-Quality Electron Transport Layer. MICROMACHINES 2023; 14:1483. [PMID: 37630019 PMCID: PMC10456511 DOI: 10.3390/mi14081483] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/13/2023] [Revised: 07/18/2023] [Accepted: 07/20/2023] [Indexed: 08/27/2023]
Abstract
The electron transport layer (ETL) plays a crucial role in solar cell technology, particularly in perovskite solar cells (PSCs), where nanostructured TiO2 films have been investigated as superior ETLs compared to compact TiO2. In this study, we explored the nanocolumnar growth of TiO2 in the anatase phase for bilayer thin films by DC reactive magnetron sputtering (MS) technique and glancing-angle deposition (GLAD). For the growth of the compact TiO2 layer, it was found that the crystalline quality of the films is strongly dependent on the sputtering power, and the samples deposited at 120 and 140 W are those with the best crystalline quality. However, for the nanocolumnar layer, the reactive atmosphere composition determined the best crystalline properties. By optimizing the growth parameters, the formation of TiO2 nanocolumns with a cross-sectional diameter ranging from 50 to 75 nm was achieved. The average thickness of the films exceeded 12.71 ± 0.5 µm. All nanostructured films were grown at a constant GLAD angle of 70°, and after deposition, the measured inclination angle of the nanocolumns is very close to this, having values between 68 and 80°. Furthermore, a correlation was observed between the quality of the initial layer and the enhanced growth of the TiO2 nanocolumns. All bilayer films are highly transparent, allowing light to pass through up to 90%, and present a band gap with values between 3.7 and 3.8 eV. This article offers the experimental parameters for the fabrication of a nanocolumnar TiO2 using the magnetron sputtering technique and the glancing-angle deposition configuration.
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Affiliation(s)
- Perla Yanet Rosales Medina
- Unidad Académica de Física, Universidad Autónoma de Zacatecas, Campus Universitario II, Av. Preparatoria S/N, Col. Hidráulica, Zacatecas 98068, Mexico; (F.A.M.); (E.F.S.); (R.G.R.); (J.A.B.T.); (J.d.J.A.I.); (H.T.H.); (J.J.O.S.)
| | - Fernando Avelar Muñoz
- Unidad Académica de Física, Universidad Autónoma de Zacatecas, Campus Universitario II, Av. Preparatoria S/N, Col. Hidráulica, Zacatecas 98068, Mexico; (F.A.M.); (E.F.S.); (R.G.R.); (J.A.B.T.); (J.d.J.A.I.); (H.T.H.); (J.J.O.S.)
| | - Elida Flores Sigala
- Unidad Académica de Física, Universidad Autónoma de Zacatecas, Campus Universitario II, Av. Preparatoria S/N, Col. Hidráulica, Zacatecas 98068, Mexico; (F.A.M.); (E.F.S.); (R.G.R.); (J.A.B.T.); (J.d.J.A.I.); (H.T.H.); (J.J.O.S.)
| | - Roberto Gómez Rosales
- Unidad Académica de Física, Universidad Autónoma de Zacatecas, Campus Universitario II, Av. Preparatoria S/N, Col. Hidráulica, Zacatecas 98068, Mexico; (F.A.M.); (E.F.S.); (R.G.R.); (J.A.B.T.); (J.d.J.A.I.); (H.T.H.); (J.J.O.S.)
| | - Javier Alejandro Berumen Torres
- Unidad Académica de Física, Universidad Autónoma de Zacatecas, Campus Universitario II, Av. Preparatoria S/N, Col. Hidráulica, Zacatecas 98068, Mexico; (F.A.M.); (E.F.S.); (R.G.R.); (J.A.B.T.); (J.d.J.A.I.); (H.T.H.); (J.J.O.S.)
| | - José de Jesús Araiza Ibarra
- Unidad Académica de Física, Universidad Autónoma de Zacatecas, Campus Universitario II, Av. Preparatoria S/N, Col. Hidráulica, Zacatecas 98068, Mexico; (F.A.M.); (E.F.S.); (R.G.R.); (J.A.B.T.); (J.d.J.A.I.); (H.T.H.); (J.J.O.S.)
| | - Hugo Tototzintle Huitle
- Unidad Académica de Física, Universidad Autónoma de Zacatecas, Campus Universitario II, Av. Preparatoria S/N, Col. Hidráulica, Zacatecas 98068, Mexico; (F.A.M.); (E.F.S.); (R.G.R.); (J.A.B.T.); (J.d.J.A.I.); (H.T.H.); (J.J.O.S.)
| | - Víctor Hugo Méndez García
- CIACYT, Universidad Autónoma de San Luis Potosí, Av. Sierra Leona #550-2A, Col. Lomas de San Luis, San Luis Potosí 78210, Mexico;
| | - José Juan Ortega Sigala
- Unidad Académica de Física, Universidad Autónoma de Zacatecas, Campus Universitario II, Av. Preparatoria S/N, Col. Hidráulica, Zacatecas 98068, Mexico; (F.A.M.); (E.F.S.); (R.G.R.); (J.A.B.T.); (J.d.J.A.I.); (H.T.H.); (J.J.O.S.)
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Preparation and Real World Applications of Titania Composite Materials for Photocatalytic Surface, Air, and Water Purification: State of the Art. INORGANICS 2022. [DOI: 10.3390/inorganics10090139] [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
The semiconducting transition metal oxide TiO2 is a rather cheap and non-toxic material with superior photocatalytic properties. TiO2 thin films and nanoparticles are known to have antibacterial, antiviral, antifungal, antialgal, self, water, and air-cleaning properties under UV or sun light irradiation. Based on these excellent qualities, titania holds great promises in various fields of applications. The vast majority of published field and pilot scale studies are dealing with the modification of building materials or generally focus on air purification. Based on the reviewed papers, for the coating of glass, walls, ceilings, streets, tunnels, and other large surfaces, titania is usually applied by spray-coating due to the scalibility and cost-efficiency of this method compared to alternative coating procedures. In contrast, commercialized applications of titania in medical fields or in water purification are rarely found. Moreover, in many realistic test scenarios it becomes evident that the photocatalytic activity is often significantly lower than in laboratory settings. In this review, we will give an overview on the most relevant real world applications and commonly applied preparation methods for these purposes. We will also look at the relevant bottlenecks such as visible light photocatalytic activity and long-term stability and will make suggestions to overcome these hurdles for a widespread usage of titania as photocalyst.
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Milenov T, Terziyska P, Avdeev G, Karashanova D, Georgieva B, Avramova I, Genkov K, Valcheva E. Structure and Phase Composition Study of Heavy Doped with Carbon Thin Films of TiO2 : C Deposited by RF Magnetron Sputtering. RUSS J INORG CHEM+ 2022. [DOI: 10.1134/s0036023622100333] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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Fawzi T, Rani S, Roy SC, Lee H. Photocatalytic Carbon Dioxide Conversion by Structurally and Materially Modified Titanium Dioxide Nanostructures. Int J Mol Sci 2022; 23:ijms23158143. [PMID: 35897719 PMCID: PMC9330242 DOI: 10.3390/ijms23158143] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2022] [Revised: 07/21/2022] [Accepted: 07/22/2022] [Indexed: 12/18/2022] Open
Abstract
TiO2 has aroused considerable attentions as a promising photocatalytic material for decades due to its superior material properties in several fields such as energy and environment. However, the main dilemmas are its wide bandgap (3–3.2 eV), that restricts the light absorption in limited light wavelength region, and the comparatively high charge carrier recombination rate of TiO2, is a hurdle for efficient photocatalytic CO2 conversion. To tackle these problems, lots of researches have been implemented relating to structural and material modification to improve their material, optical, and electrical properties for more efficient photocatalytic CO2 conversion. Recent studies illustrate that crystal facet engineering could broaden the performance of the photocatalysts. As same as for nanostructures which have advantages such as improved light absorption, high surface area, directional charge transport, and efficient charge separation. Moreover, strategies such as doping, junction formation, and hydrogenation have resulted in a promoted photocatalytic performance. Such strategies can markedly change the electronic structure that lies behind the enhancement of the solar spectrum harnessing. In this review, we summarize the works that have been carried out for the enhancement of photocatalytic CO2 conversion by material and structural modification of TiO2 and TiO2-based photocatalytic system. Moreover, we discuss several strategies for synthesis and design of TiO2 photocatalysts for efficient CO2 conversion by nanostructure, structure design of photocatalysts, and material modification.
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Affiliation(s)
- Tarek Fawzi
- Department of Photonics, National Sun Yat-sen University, No. 70, Lien-Hai Rd, Kaohsiung 80424, Taiwan; or
| | - Sanju Rani
- Department of Physics, SRM Institute of Science and Technology, Ramapuram Campus, Chennai 600089, Tamil Nadu, India;
| | - Somnath C. Roy
- Semiconducting Oxide Materials, Nanostructures and Tailored Heterojunction (SOMNaTH) Lab, Functional Oxides Research Group (FORG) and 2D Materials and Innovation Centre, Department of Physics, IIT Madras, Chennai 600036, Tamil Nadu, India;
| | - Hyeonseok Lee
- Department of Photonics, National Sun Yat-sen University, No. 70, Lien-Hai Rd, Kaohsiung 80424, Taiwan; or
- Correspondence: ; Tel.: +886-7-525-2000 (ext. 4473)
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Fernández S, Torres I, Gandía JJ. Sputtered Ultrathin TiO 2 as Electron Transport Layer in Silicon Heterojunction Solar Cell Technology. NANOMATERIALS 2022; 12:nano12142441. [PMID: 35889664 PMCID: PMC9317026 DOI: 10.3390/nano12142441] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/31/2022] [Revised: 06/23/2022] [Accepted: 07/14/2022] [Indexed: 02/06/2023]
Abstract
This work presents the implementation of ultrathin TiO2 films, deposited at room temperature by radio-frequency magnetron sputtering, as electron-selective contacts in silicon heterojunction solar cells. The effect of the working pressure on the properties of the TiO2 layers and its subsequent impact on the main parameters of the device are studied. The material characterization revealed an amorphous structure regardless of the working pressure; a rougher surface; and a blue shift in bandgap in the TiO2 layer deposited at the highest-pressure value of 0.89 Pa. When incorporated as part of the passivated full-area electron contact in silicon heterojunction solar cell, the chemical passivation provided by the intrinsic a-Si:H rapidly deteriorates upon the sputtering of the ultra-thin TiO2 films, although a short anneal is shown to restore much of the passivation lost. The deposition pressure and film thicknesses proved to be critical for the efficiency of the devices. The film thicknesses below 2 nm are necessary to reach open-circuit values above 660 mV, regardless of the deposition pressure. More so, the fill-factor showed a strong dependence on deposition pressure, with the best values obtained for the highest deposition pressure, which we correlated to the porosity of the films. Overall, these results show the potential to fabricate silicon solar cells with a simple implementation of electron-selective TiO2 contact deposited by magnetron sputtering. These results show the potential to fabricate silicon solar cells with a simple implementation of electron-selective TiO2 contact.
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Affiliation(s)
| | - Ignacio Torres
- Correspondence: (S.F.); (I.T.); Tel.: +34913466039 (S.F.)
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8
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The Sensitization of TiO2 Thin Film by Ag Nanoparticles for the Improvement of Photocatalytic Efficiency. APPLIED SCIENCES-BASEL 2022. [DOI: 10.3390/app12115725] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
The formation of Ag nanoparticles on the surface of TiO2 (AgNP/TiO2) to enhance photocatalytic efficiency was studied. The Ag nanoparticles (AgNP) size, form, and distribution dependence on the initial thickness of Ag thin films, annealing temperature, and time were analyzed. The optimal annealing temperature of 400 °C and annealing time of 60 min were chosen to form AgNP from the initial Ag thin films with a thickness of 5, 7.5, and 10 nm. The formation of AgNP was done on amorphous TiO2 (a-TiO2), which crystallized into the anatase phase after the annealing. The photocatalytic efficiency (k–degradation rate constant, Defi–degradation efficiency) was evaluated by the photodegradation of Rhodamine B aqueous solution. The results suggested that the highest photocatalytic efficiency of Rhodamine B aqueous solution was reached where the average diameter (DA) of AgNP was ~38 nm (k38 = 0.017 min−1, Defi_38 = 63.5%), compared to 27 and 82 nm (k27 = 0.012 min−1, Defi_27 = 51.2% and k82 = 0.011 min−1, Defi_82 = 52.1%, respectively). The acquired results did not show clear correlation between the size and distribution of the AgNP on the TiO2 surface and photocatalytic efficiency. Nevertheless, the results suggest that AgNP can enhance the photocatalytic efficiency of TiO2 thin films (kTiO2 = 0.008 min−1, Defi_TiO2 = 36.3%).
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Abid N, Khan AM, Shujait S, Chaudhary K, Ikram M, Imran M, Haider J, Khan M, Khan Q, Maqbool M. Synthesis of nanomaterials using various top-down and bottom-up approaches, influencing factors, advantages, and disadvantages: A review. Adv Colloid Interface Sci 2022; 300:102597. [PMID: 34979471 DOI: 10.1016/j.cis.2021.102597] [Citation(s) in RCA: 108] [Impact Index Per Article: 54.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/27/2021] [Revised: 12/07/2021] [Accepted: 12/25/2021] [Indexed: 12/25/2022]
Abstract
Nanotechnology is one of the emerging fields of the 21st Century. Many new devices and patentable technology is based on nanomaterials (NMs). One of the dominant factors in the use of nanomaterials and their applications in various fields is the synthesis and growth mechanism of nanostructures and nanomaterials. A nanostructured material may have been a good candidate in one application but could be more useful in a different application if synthesized by a different mechanism and technique. Similarly, the structure and morphology of a nanomaterial also depend upon the method of growth and synthesis. For example, it is easy to grow and synthesize amorphous nanostructured thin film using the plasma magnetron sputtering technique, but it may be difficult to obtain a similar structure using the thermal evaporation process due to the nature of the technique itself. In this study, the Top-down and Bottom-up methods and techniques of synthesizing nanostructured materials are reviewed, compared, and analyzed. Both approaches are critically analyzed, and the influencing factors on the synthesis of different nanomaterials, the advantages, and disadvantages of each technique are reported. This review also provides a step-by-step analysis of the choice of method for the synthesis of namomaterials for specific applications.
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Affiliation(s)
- Namra Abid
- Physics Department, Lahore Garrison University, Lahore 54000, Punjab, Pakistan
| | - Aqib Muhammad Khan
- Department of Physics, Riphah Institute of Computing and Applied Sciences (RICAS), Riphah International University, 14 Ali Road, Lahore, Pakistan
| | - Sara Shujait
- Physics Department, Lahore Garrison University, Lahore 54000, Punjab, Pakistan
| | - Kainat Chaudhary
- Physics Department, Lahore Garrison University, Lahore 54000, Punjab, Pakistan
| | - Muhammad Ikram
- Solar Cell Application Research Lab, Department of Physics, Government College University Lahore, Lahore 54000, Punjab, Pakistan.
| | - Muhammad Imran
- State Key Laboratory of Chemical Resource Engineering, Beijing Advanced Innovation Centre for Soft Matter Science and Engineering, Beijing Engineering Centre for Hierarchical Catalysts, Beijing University of Chemical Technology, Beijing 100029, China
| | - Junaid Haider
- Tianjin Institute of Industrial Biotechnology, Chinese Academy of Sciences, Tianjin 300308, China
| | - Maaz Khan
- Nanomaterials Research Group, Physics Division, PINSTECH, Islamabad, Pakistan
| | - Qasim Khan
- Institute of Microscale Optoelectronics, Shenzhen University, Shenzhen, Guangdong 518000, China.
| | - Muhammad Maqbool
- Department of Clinical & Diagnostic Sciences, Health Physics Program, the University of Alabama at Birmingham, USA.
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Anucha CB, Altin I, Bacaksiz E, Stathopoulos VN. Titanium Dioxide (TiO₂)-Based Photocatalyst Materials Activity Enhancement for Contaminants of Emerging Concern (CECs) Degradation: In the Light of Modification Strategies. CHEMICAL ENGINEERING JOURNAL ADVANCES 2022. [DOI: 10.1016/j.ceja.2022.100262] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022] Open
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11
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Wang Z, Li S, Wang J, Shao Y, Mei L. A recyclable graphene/Ag/TiO 2 SERS substrate with high stability and reproducibility for detection of dye molecules. NEW J CHEM 2022. [DOI: 10.1039/d2nj02577a] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
Magnetron sputtering combined with the wet chemical transfer of graphene successfully prepared a multilayer composite material and an efficient photocatalytic renewable SERS substrate. It has excellent photocatalytic activity against dye molecules.
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Affiliation(s)
- Zezhou Wang
- School of Mechanical Engineering, North University of China, Taiyuan, Shanxi Province 030051, China
| | - Sha Li
- School of Mechanical Engineering, North University of China, Taiyuan, Shanxi Province 030051, China
| | - Junyuan Wang
- School of Mechanical Engineering, North University of China, Taiyuan, Shanxi Province 030051, China
| | - Yunpeng Shao
- School of Mechanical Engineering, North University of China, Taiyuan, Shanxi Province 030051, China
| | - Linyu Mei
- School of Mechanical Engineering, North University of China, Taiyuan, Shanxi Province 030051, China
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12
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Plasmonic Spherical Nanoparticles Coupled with Titania Nanotube Arrays Prepared by Anodization as Substrates for Surface-Enhanced Raman Spectroscopy Applications: A Review. Molecules 2021; 26:molecules26247443. [PMID: 34946522 PMCID: PMC8705377 DOI: 10.3390/molecules26247443] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/05/2021] [Revised: 12/02/2021] [Accepted: 12/03/2021] [Indexed: 12/17/2022] Open
Abstract
As surface-enhanced Raman spectroscopy (SERS) continues developing to be a powerful analytical tool for several probes, four important aspects to make it more accessible have to be addressed: low-cost, reproducibility, high sensibility, and recyclability. Titanium dioxide nanotubes (TiO2 NTs) prepared by anodization have attracted interest in this field because they can be used as safe solid supports to deposit metal nanoparticles to build SERS substrate nanoplatforms that meet these four desired aspects. TiO2 NTs can be easily prepared and, by varying different synthesis parameters, their dimensions and specific features of their morphology can be tuned allowing them to support metal nanoparticles of different sizes that can achieve a regular dispersion on their surface promoting high enhancement factors (EF) and reproducibility. Besides, the TiO2 photocatalytic properties enable the substrate's self-cleaning property for recyclability. In this review, we discuss the different methodological strategies that have been tested to achieve a high performance of the SERS substrates based on TiO2 NTs as solid support for the three main noble metal nanoparticles mainly studied for this purpose: Ag, Au, and Pt.
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Zouzelka R, Olejnicek J, Ksirova P, Hubicka Z, Duchon J, Martiniakova I, Muzikova B, Mergl M, Kalbac M, Brabec L, Kocirik M, Remzova M, Vaneckova E, Rathousky J. Hierarchical TiO 2 Layers Prepared by Plasma Jets. NANOMATERIALS 2021; 11:nano11123254. [PMID: 34947602 PMCID: PMC8706491 DOI: 10.3390/nano11123254] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 10/27/2021] [Revised: 11/24/2021] [Accepted: 11/25/2021] [Indexed: 11/16/2022]
Abstract
Heterogeneous photocatalysis of TiO2 is one of the most efficient advanced oxidation processes for water and air purification. Here, we prepared hierarchical TiO2 layers (Spikelets) by hollow-cathode discharge sputtering and tested their photocatalytic performance in the abatement of inorganic (NO, NO2) and organic (4-chlorophenol) pollutant dispersed in air and water, respectively. The structural-textural properties of the photocatalysts were determined via variety of physico-chemical techniques (XRD, Raman spectroscopy, SEM, FE-SEM. DF-TEM, EDAX and DC measurements). The photocatalysis was carried out under conditions similar to real environment conditions. Although the abatement of NO and NO2 was comparable with that of industrial benchmark Aeroxide® TiO2 P25, the formation of harmful nitrous acid (HONO) product on the Spikelet TiO2 layers was suppressed. Similarly, in the decontamination of water by organics, the mineralization of 4-chlorophenol on Spikelet layers was interestingly the same, although their reaction rate constant was three-times lower. The possible explanation may be the more than half-magnitude order higher external quantum efficacy (EQE) compared to that of the reference TiO2 P25 layer. Therefore, such favorable kinetics and reaction selectivity, together with feasible scale-up, make the hierarchical TiO2 layers very promising photocatalyst which can be used for environmental remediation.
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Affiliation(s)
- Radek Zouzelka
- J. Heyrovsky Institute of Physical Chemistry, Czech Academy of Sciences, Dolejskova 3, 182 23 Prague, Czech Republic; (I.M.); (B.M.); (M.M.); (M.K.); (L.B.); (M.K.); (M.R.); (E.V.)
- Correspondence: (R.Z.); (J.R.); Tel.: +420-266-05-34-04 (R.Z.); +420-266-05-30-95 (J.R.)
| | - Jiri Olejnicek
- Institute of Physics, Czech Academy of Sciences, Na Slovance 2, 182 21 Prague, Czech Republic; (J.O.); (P.K.); (Z.H.); (J.D.)
| | - Petra Ksirova
- Institute of Physics, Czech Academy of Sciences, Na Slovance 2, 182 21 Prague, Czech Republic; (J.O.); (P.K.); (Z.H.); (J.D.)
| | - Zdenek Hubicka
- Institute of Physics, Czech Academy of Sciences, Na Slovance 2, 182 21 Prague, Czech Republic; (J.O.); (P.K.); (Z.H.); (J.D.)
| | - Jan Duchon
- Institute of Physics, Czech Academy of Sciences, Na Slovance 2, 182 21 Prague, Czech Republic; (J.O.); (P.K.); (Z.H.); (J.D.)
| | - Ivana Martiniakova
- J. Heyrovsky Institute of Physical Chemistry, Czech Academy of Sciences, Dolejskova 3, 182 23 Prague, Czech Republic; (I.M.); (B.M.); (M.M.); (M.K.); (L.B.); (M.K.); (M.R.); (E.V.)
| | - Barbora Muzikova
- J. Heyrovsky Institute of Physical Chemistry, Czech Academy of Sciences, Dolejskova 3, 182 23 Prague, Czech Republic; (I.M.); (B.M.); (M.M.); (M.K.); (L.B.); (M.K.); (M.R.); (E.V.)
| | - Martin Mergl
- J. Heyrovsky Institute of Physical Chemistry, Czech Academy of Sciences, Dolejskova 3, 182 23 Prague, Czech Republic; (I.M.); (B.M.); (M.M.); (M.K.); (L.B.); (M.K.); (M.R.); (E.V.)
| | - Martin Kalbac
- J. Heyrovsky Institute of Physical Chemistry, Czech Academy of Sciences, Dolejskova 3, 182 23 Prague, Czech Republic; (I.M.); (B.M.); (M.M.); (M.K.); (L.B.); (M.K.); (M.R.); (E.V.)
| | - Libor Brabec
- J. Heyrovsky Institute of Physical Chemistry, Czech Academy of Sciences, Dolejskova 3, 182 23 Prague, Czech Republic; (I.M.); (B.M.); (M.M.); (M.K.); (L.B.); (M.K.); (M.R.); (E.V.)
| | - Milan Kocirik
- J. Heyrovsky Institute of Physical Chemistry, Czech Academy of Sciences, Dolejskova 3, 182 23 Prague, Czech Republic; (I.M.); (B.M.); (M.M.); (M.K.); (L.B.); (M.K.); (M.R.); (E.V.)
| | - Monika Remzova
- J. Heyrovsky Institute of Physical Chemistry, Czech Academy of Sciences, Dolejskova 3, 182 23 Prague, Czech Republic; (I.M.); (B.M.); (M.M.); (M.K.); (L.B.); (M.K.); (M.R.); (E.V.)
| | - Eva Vaneckova
- J. Heyrovsky Institute of Physical Chemistry, Czech Academy of Sciences, Dolejskova 3, 182 23 Prague, Czech Republic; (I.M.); (B.M.); (M.M.); (M.K.); (L.B.); (M.K.); (M.R.); (E.V.)
| | - Jiri Rathousky
- J. Heyrovsky Institute of Physical Chemistry, Czech Academy of Sciences, Dolejskova 3, 182 23 Prague, Czech Republic; (I.M.); (B.M.); (M.M.); (M.K.); (L.B.); (M.K.); (M.R.); (E.V.)
- Correspondence: (R.Z.); (J.R.); Tel.: +420-266-05-34-04 (R.Z.); +420-266-05-30-95 (J.R.)
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A High-Efficiency TiO 2/ZnO Nano-Film with Surface Oxygen Vacancies for Dye Degradation. MATERIALS 2021; 14:ma14123299. [PMID: 34203670 PMCID: PMC8232121 DOI: 10.3390/ma14123299] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/19/2021] [Revised: 05/29/2021] [Accepted: 06/02/2021] [Indexed: 12/14/2022]
Abstract
Photocatalytic degradation of organic pollutants in water is a highly efficient and green approach. However, the low quantum efficiency is an intractable obstacle to lower the photocatalytic efficiency of photocatalysts. Herein, the TiO2/ZnO heterojunction thin films combined with surface oxygen vacancies (OVs) were prepared through magnetron sputtering, which was designed to drive rapid bulk and surface separation of charge carriers. The morphology and structural and compositional properties of films were investigated via different techniques such as SEM, XRD, Raman, AFM, and XPS. It has been found that by controlling the O2/Ar ratio, the surface morphology, thickness, chemical composition, and crystal structure can be regulated, ultimately enhancing the photocatalytic performance of the TiO2/ZnO heterostructures. In addition, the heterojunction thin film showed improved photocatalytic properties compared with the other nano-films when the outer TiO2 layer was prepared at an O2/Ar ratio of 10:35. It degraded 88.0% of Rhodamine B (RhB) in 90 min and 90.8% of RhB in 120 min. This was attributed to the heterojunction interface and surface OVs, which accelerated the separation of electron–hole (e–h) pairs.
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Special Issue: New Trends in Photo (Electro)catalysis: From Wastewater Treatment to Energy Production. Catalysts 2021. [DOI: 10.3390/catal11050586] [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
This Special Issue aimed at focusing on photo- and photo-electrocatalytic processes specifically devoted to present both new catalytic materials and possible applications in environmental and energetic fields [...]
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