1
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Hyun Kim Y, Gyeong Bae Y, Yong Sohn W. Uncovering Energetic Positions of Surface Trap States in α-Fe 2O 3 Treated with Cobalt Phosphate (Co-Pi) Using Charge Carrier-Selective Heterodyne Transient Grating Technique. Chemphyschem 2024; 25:e202300894. [PMID: 38369879 DOI: 10.1002/cphc.202300894] [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: 11/22/2023] [Revised: 02/17/2024] [Accepted: 02/18/2024] [Indexed: 02/20/2024]
Abstract
Near-field heterodyne transient grating (NF-HD-TG) responses of hematite (α-Fe2O3) treated with cobalt phosphate (Co-Pi) were measured with the burn lasers inducing the depletion of the response by the removal of the trapped charge carriers in the target state, which is called charge carrier-selective heterodyne transient grating (CS-HD-TG) spectroscopic technique. We found that two distinct trap states co-existed in Co-Pi loaded on the surface of α-Fe2O3. One of them named r-SS2, of which potential was similar to that of r-SS1 in the surface of α-Fe2O3, acted as a recombination centre but could increase the lifetime of the trapped holes by the charge separation. We also revealed that the energetic position of the other (i-SS2), which has been regarded as the intermediate state for oxygen evolution reaction with low overpotential, was higher than that of i-SS1 in α-Fe2O3 but lower than those of r-SS1 and r-SS2.
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Affiliation(s)
- Young Hyun Kim
- Department of Chemistry, Chungbuk National University, Chungdae-ro 1, Cheongju, Chungbuk 28644, Korea
| | - Yu Gyeong Bae
- Department of Chemistry, Chungbuk National University, Chungdae-ro 1, Cheongju, Chungbuk 28644, Korea
| | - Woon Yong Sohn
- Department of Chemistry, Chungbuk National University, Chungdae-ro 1, Cheongju, Chungbuk 28644, Korea
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2
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Katayama K. Pattern-illumination time-resolved phase microscopy and its applications for photocatalytic and photovoltaic materials. Phys Chem Chem Phys 2024; 26:9783-9815. [PMID: 38497609 DOI: 10.1039/d3cp06211b] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/19/2024]
Abstract
Pattern-illumination time-resolved phase microscopy (PI-PM) is a technique used to study the microscopic charge carrier dynamics in photocatalytic and photovoltaic materials. The method involves illuminating a sample with a pump light pattern, which generates charge carriers and they decay subsequently due to trapping, recombination, and transfer processes. The distribution of photo-excited charge carriers is observed through refractive index changes using phase-contrast imaging. In the PI-PM method, the sensitivity of the refractive index change is enhanced by adjusting the focus position, the method takes advantage of photo-excited charge carriers to observe non-radiative processes, such as charge diffusion, trapping in defect/surface states, and interfacial charge transfer of photocatalytic and photovoltaic reactions. The quality of the image sequence is recovered using various informatics calculations. Categorizing and mapping different types of charge carriers based on their response profiles using clustering analysis provides spatial information on charge carrier types and the identification of local sites for efficient and inefficient photo-induced reactions, providing valuable information for the design and optimization of photocatalytic materials such as the cocatalyst effect.
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Affiliation(s)
- Kenji Katayama
- Department of Applied Chemistry, Chuo University, Tokyo 112-8551, Japan.
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3
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Wenderich K, Zhu K, Bu Y, Tichelaar FD, Mul G, Huijser A. Photophysical Characterization of Ru Nanoclusters on Nanostructured TiO 2 by Time-Resolved Photoluminescence Spectroscopy. THE JOURNAL OF PHYSICAL CHEMISTRY. C, NANOMATERIALS AND INTERFACES 2023; 127:14353-14362. [PMID: 37529662 PMCID: PMC10388344 DOI: 10.1021/acs.jpcc.3c04075] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 06/16/2023] [Revised: 06/23/2023] [Indexed: 08/03/2023]
Abstract
Despite the promising performance of Ru nanoparticles or nanoclusters on nanostructured TiO2 in photocatalytic and photothermal reactions, a mechanistic understanding of the photophysics is limited. The aim of this study is to uncover the nature of light-induced processes in Ru/TiO2 and the role of UV versus visible excitation by time-resolved photoluminescence (PL) spectroscopy. The PL at a 267 nm excitation is predominantly due to TiO2, with a minor contribution of the Ru nanoclusters. Relative to TiO2, the PL of Ru/TiO2 following a 267 nm excitation is significantly blue-shifted, and the bathochromic shift with time is smaller. We show by global analysis of the spectrotemporal PL behavior that for both TiO2 and Ru/TiO2 the bathochromic shift with time is likely caused by the diffusion of electrons from the TiO2 bulk toward the surface. During this directional motion, electrons may recombine (non)radiatively with relatively immobile hole polarons, causing the PL spectrum to red-shift with time following excitation. The blue-shifted PL spectra and smaller bathochromic shift with time for Ru/TiO2 relative to TiO2 indicate surface PL quenching, likely due to charge transfer from the TiO2 surface into the Ru nanoclusters. When deposited on SiO2 and excited at 532 nm, Ru shows a strong emission. The PL of Ru when deposited on TiO2 is completely quenched, demonstrating interfacial charge separation following photoexcitation of the Ru nanoclusters with a close to unity quantum yield. The nature of the charge-transfer phenomena is discussed, and the obtained insights indicate that Ru nanoclusters should be deposited on semiconducting supports to enable highly effective photo(thermal)catalysis.
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Affiliation(s)
- Kasper Wenderich
- Photocatalytic
Synthesis Group, Faculty of Science and Technology, MESA+ Institute
for Nanotechnology, University of Twente, P.O. Box 217, 7500 AE Enschede, The Netherlands
| | - Kaijian Zhu
- Photocatalytic
Synthesis Group, Faculty of Science and Technology, MESA+ Institute
for Nanotechnology, University of Twente, P.O. Box 217, 7500 AE Enschede, The Netherlands
| | - Yibin Bu
- Nanolab,
MESA+ Institute for Nanotechnology, University
of Twente, P.O. Box 217, 7500 AE Enschede, The Netherlands
| | - Frans D. Tichelaar
- Kavli
Institute of Technology, Quantum Nanoscience, Delft University of Technology, 2628 CJ Delft, The Netherlands
| | - Guido Mul
- Photocatalytic
Synthesis Group, Faculty of Science and Technology, MESA+ Institute
for Nanotechnology, University of Twente, P.O. Box 217, 7500 AE Enschede, The Netherlands
| | - Annemarie Huijser
- Photocatalytic
Synthesis Group, Faculty of Science and Technology, MESA+ Institute
for Nanotechnology, University of Twente, P.O. Box 217, 7500 AE Enschede, The Netherlands
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4
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Minato A, Pan Z, Katayama K, Yong Sohn W. Enhancement of photoelectrochemical performance of Bismuth vanadate (BiVO4)-Based photoanode by building phase-junction configurations. J Photochem Photobiol A Chem 2023. [DOI: 10.1016/j.jphotochem.2022.114252] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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5
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Hyun Kim J, Kyung Lee N, Won Kim H, Pan Z, Yong Sohn W. Sequential Modifications of the Surface of Hematite (α-Fe2O3) Photoanodes with Amorphous Nickel Iron Oxide (NiFeOx) and Cobalt Phosphate (Co-Pi). J Photochem Photobiol A Chem 2022. [DOI: 10.1016/j.jphotochem.2022.114478] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
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6
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Cui Z, Zhao M, Li S, Wang J, Xu Y, Ghazzal MN, Colbeau-Justin C, Pan D, Wu W. Facile Vacuum Annealing of TiO 2 with Ethanol-Induced Enhancement of Its Photocatalytic Performance under Visible Light. Ind Eng Chem Res 2022. [DOI: 10.1021/acs.iecr.2c01842] [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]
Affiliation(s)
- Zhenpeng Cui
- Frontiers Science Center for Rare Isotopes, Lanzhou University, Lanzhou 730000, China
- School of Nuclear Science and Technology, Lanzhou University, Lanzhou 730000, China
| | - Min Zhao
- School of Nuclear Science and Technology, Lanzhou University, Lanzhou 730000, China
| | - Shuyang Li
- School of Nuclear Science and Technology, Lanzhou University, Lanzhou 730000, China
| | - Jingjing Wang
- School of Nuclear Science and Technology, Lanzhou University, Lanzhou 730000, China
| | - Yang Xu
- School of Nuclear Science and Technology, Lanzhou University, Lanzhou 730000, China
| | - Mohamed Nawfal Ghazzal
- Institue de Chimie Physique, UMR 8000 CNRS, Université Paris-Saclay, Orsay 91405, France
| | | | - Duoqiang Pan
- Frontiers Science Center for Rare Isotopes, Lanzhou University, Lanzhou 730000, China
- School of Nuclear Science and Technology, Lanzhou University, Lanzhou 730000, China
| | - Wangsuo Wu
- Frontiers Science Center for Rare Isotopes, Lanzhou University, Lanzhou 730000, China
- School of Nuclear Science and Technology, Lanzhou University, Lanzhou 730000, China
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7
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Zhang X, Tang P, Zhai G, Lin X, Zhang Q, Chen J, Wei X. Regulating Phase Junction and Oxygen Vacancies of TiO2 Nanoarrays for Boosted Photoelectrochemical Water Oxidation. Chem Res Chin Univ 2022. [DOI: 10.1007/s40242-022-2076-z] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
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8
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Kim HW, Won JY, Pan Z, Sohn WY. Tailoring the morphology of hafnium zirconium oxide (Hf
0.6
Zr
0.4
O
2
) as a cocatalyst for photoelectrochemical water oxidation over a hematite (
α‐Fe
2
O
3
) photoanode. B KOREAN CHEM SOC 2022. [DOI: 10.1002/bkcs.12538] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Affiliation(s)
- Hee Won Kim
- Department of Chemistry Chungbuk National University Cheongju Chungbuk Republic of Korea
| | - Jung Yoon Won
- Department of Chemistry Chungbuk National University Cheongju Chungbuk Republic of Korea
| | - Zhenhua Pan
- Department of Applied Chemistry, Faculty of Science and Technology Chuo University Bunkyo, Tokyo Japan
| | - Woon Yong Sohn
- Department of Chemistry Chungbuk National University Cheongju Chungbuk Republic of Korea
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9
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Minato A, Katayama K, Sohn WY. Investigation of the photo-excited charge carrier dynamics in Bismuth vanadate (BiVO4) photoanode by the heterodyne transient grating technique. J Photochem Photobiol A Chem 2022. [DOI: 10.1016/j.jphotochem.2021.113659] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
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10
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Benz D, Nguyen YNT, Le TLT, Le THT, Le VT, van Ommen JR, Bui HV. Controlled growth of ultrasmall Cu 2O clusters on TiO 2nanoparticles by atmospheric-pressure atomic layer deposition for enhanced photocatalytic activity. NANOTECHNOLOGY 2021; 32:425601. [PMID: 34214992 DOI: 10.1088/1361-6528/ac10e2] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/02/2021] [Accepted: 07/02/2021] [Indexed: 06/13/2023]
Abstract
This work presents a gas-phase approach for the synthesis of Cu2O/TiO2powder-based photocatalysts using atomic layer deposition (ALD). The process is carried out in a fluidized bed reactor working at atmospheric pressure using (trimethylvinylsilyl)-hexafluoroacetulacetonate copper(I) as the Cu-precursor and H2O vapor as the oxidizer. The saturating regime of the chemical reactions and the linear growth of ALD are achieved. In combination with the unsaturated regime, the ALD approach enables the deposition of ultrasmall Cu2O clusters with average diameters in the range of 1.3-2.0 nm, narrow particle size distributions and tunable Cu2O loadings on P25 TiO2nanoparticles. The photocatalytic performance of Cu2O/TiO2photocatalysts is investigated by the degradation of organic dyes, including Rhodamine B (RhB), methyl orange, and methylene blue; the results demonstrate that the surface modification of TiO2nanoparticles by Cu2O nanoclusters significantly enhances the photocatalytic activity of TiO2. This is attributed to the efficient charge transfer between Cu2O and TiO2that reduces the charge recombination. The photocatalytic reaction mechanism is further investigated for the degradation of RhB, revealing the dominating role of holes, which contribute to both direct hole oxidation and indirect oxidation (i.e. via the formation of hydroxyl radicals). Our approach provides a fast, scalable and efficient process to deposit ultrasmall Cu2O clusters in a controllable fashion for surface engineering and modification.
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Affiliation(s)
- Dominik Benz
- Product & Process Engineering, Department of Chemical Engineering, Faculty of Applied Sciences, Delft University of Technology, 2629 HZ Delft, The Netherlands
| | - Y-Nhi T Nguyen
- Faculty of Natural Sciences, Quy Nhon University, 170 An Duong Vuong, Quy Nhon City 55000, Vietnam
| | - Thanh-Lieu T Le
- Faculty of Natural Sciences, Quy Nhon University, 170 An Duong Vuong, Quy Nhon City 55000, Vietnam
| | - Thanh-Hiep T Le
- Faculty of Natural Sciences, Quy Nhon University, 170 An Duong Vuong, Quy Nhon City 55000, Vietnam
| | - Viet-Thong Le
- Faculty of Materials Science and Engineering, Phenikaa University, Yen Nghia, Ha-Dong District, Hanoi 12116, Vietnam
- Faculty of Electrical and Electronic Engineering, Phenikaa University, Yen Nghia, Ha-Dong District, Hanoi 12116, Vietnam
| | - J Ruud van Ommen
- Product & Process Engineering, Department of Chemical Engineering, Faculty of Applied Sciences, Delft University of Technology, 2629 HZ Delft, The Netherlands
| | - Hao Van Bui
- Faculty of Materials Science and Engineering, Phenikaa University, Yen Nghia, Ha-Dong District, Hanoi 12116, Vietnam
- Faculty of Electrical and Electronic Engineering, Phenikaa University, Yen Nghia, Ha-Dong District, Hanoi 12116, Vietnam
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11
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Charge carrier mapping for Z-scheme photocatalytic water-splitting sheet via categorization of microscopic time-resolved image sequences. Nat Commun 2021; 12:3716. [PMID: 34140521 PMCID: PMC8211828 DOI: 10.1038/s41467-021-24061-4] [Citation(s) in RCA: 24] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2021] [Accepted: 05/27/2021] [Indexed: 11/08/2022] Open
Abstract
Photocatalytic water splitting system using particulate semiconductor materials is a promising strategy for converting solar energy into hydrogen and oxygen. In particular, visible-light-driven 'Z-scheme' printable photocatalyst sheets are cost-effective and scalable. However, little is known about the fundamental photophysical processes, which are key to explaining and promoting the photoactivity. Here, we applied the pattern-illumination time-resolved phase microscopy for a photocatalyst sheet composed of Mo-doped BiVO4 and Rh-doped SrTiO3 with indium tin oxide as the electron mediator to investigate photo-generated charge carrier dynamics. Using this method, we successfully observed the position- and structure-dependent charge carrier behavior and visualized the active/inactive sites in the sheets under the light irradiation via the time sequence images and the clustering analysis. This combination methodology could provide the material/synthesis optimization methods for the maximum performance of the photocatalyst sheets.
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12
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Garcia JM, Heald LF, Shaffer RE, Sayres SG. Oscillation in Excited State Lifetimes with Size of Sub-nanometer Neutral (TiO 2) n Clusters Observed with Ultrafast Pump-Probe Spectroscopy. J Phys Chem Lett 2021; 12:4098-4103. [PMID: 33885304 DOI: 10.1021/acs.jpclett.1c00840] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/12/2023]
Abstract
Neutral titanium oxide clusters of up to 1 nm in diameter (TiO2)n, with n < 10, are produced in a laser vaporization source and subsequently ionized by a sequence of femtosecond laser pulses. Using a 400 nm pump and 800 nm probe lasers, the excited state lifetimes of neutral (TiO2)n clusters are measured. All clusters exhibit a rapid relaxation lifetime of ∼35 fs, followed by a sub-picosecond lifetime that we attribute to carrier recombination. The excited state lifetimes oscillate with size, with even-numbered clusters possessing longer lifetimes. Density functional theory calculations show the excited state lifetimes are correlated with charge carrier localization or polaron-like formation in the excited states of neutral clusters. Thus, structural rigidity is suggested as a feature for extending excited state lifetimes in titania materials.
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Affiliation(s)
- Jacob M Garcia
- School of Molecular Sciences, Arizona State University, Tempe, Arizona 85287, United States
- Biodesign Center for Applied Structural Discovery, Arizona State University, Tempe, Arizona 85287, United States
| | - Lauren F Heald
- School of Molecular Sciences, Arizona State University, Tempe, Arizona 85287, United States
- Biodesign Center for Applied Structural Discovery, Arizona State University, Tempe, Arizona 85287, United States
| | - Ryan E Shaffer
- School of Molecular Sciences, Arizona State University, Tempe, Arizona 85287, United States
- Biodesign Center for Applied Structural Discovery, Arizona State University, Tempe, Arizona 85287, United States
| | - Scott G Sayres
- School of Molecular Sciences, Arizona State University, Tempe, Arizona 85287, United States
- Biodesign Center for Applied Structural Discovery, Arizona State University, Tempe, Arizona 85287, United States
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13
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Enhanced photoelectrochemical water splitting efficiency of hematite (α-Fe2O3)-Based photoelectrode by the introduction of maghemite (γ-Fe2O3) nanoparticles. J Photochem Photobiol A Chem 2021. [DOI: 10.1016/j.jphotochem.2021.113179] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
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14
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Construction of stable Ti3+-TiO2 photocatalytic membrane for enhanced photoactivity and emulsion separation. J Memb Sci 2021. [DOI: 10.1016/j.memsci.2020.118748] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
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15
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Katayama K. Photo-excited charge carrier imaging by time-resolved pattern illumination phase microscopy. J Chem Phys 2020; 153:054201. [DOI: 10.1063/5.0009312] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Affiliation(s)
- Kenji Katayama
- Department of Applied Chemistry, Chuo University, Tokyo 112-8551, Japan and PRESTO, Japan Science and Technology Agency (JST), Saitama 332-0012, Japan
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16
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Zhao C, Wang Z, Chen X, Chu H, Fu H, Wang CC. Robust photocatalytic benzene degradation using mesoporous disk-like N-TiO2 derived from MIL-125(Ti). CHINESE JOURNAL OF CATALYSIS 2020. [DOI: 10.1016/s1872-2067(19)63516-3] [Citation(s) in RCA: 32] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
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17
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Woo An G, Dhandole LK, Park H, Sub Bae H, Mahadik MA, Suk Jang J. Enhanced Charge Transfer Process in Morphology Restructured TiO
2
Nanotubes via Hydrochloric Acid Assisted One Step
In‐Situ
Hydrothermal Approach. ChemCatChem 2019. [DOI: 10.1002/cctc.201901177] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Affiliation(s)
- Gil Woo An
- Division of Biotechnology, Advanced Institute of Environmental and Bioscience College of Environmental and Bioresource SciencesChonbuk National University Iksan 570-752 Republic of Korea
| | - Love Kumar Dhandole
- Division of Biotechnology, Advanced Institute of Environmental and Bioscience College of Environmental and Bioresource SciencesChonbuk National University Iksan 570-752 Republic of Korea
| | - Hyunwoong Park
- School of Energy EngineeringKyungpook University Daegu 41566 Republic of Korea
| | - Ho Sub Bae
- Division of Biotechnology, Advanced Institute of Environmental and Bioscience College of Environmental and Bioresource SciencesChonbuk National University Iksan 570-752 Republic of Korea
| | - Mahadeo A. Mahadik
- Division of Biotechnology, Advanced Institute of Environmental and Bioscience College of Environmental and Bioresource SciencesChonbuk National University Iksan 570-752 Republic of Korea
| | - Jum Suk Jang
- Division of Biotechnology, Advanced Institute of Environmental and Bioscience College of Environmental and Bioresource SciencesChonbuk National University Iksan 570-752 Republic of Korea
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18
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Ebihara M, Sohn WY, Katayama K. Lifetime mapping of photo-excited charge carriers by the transient grating imaging technique for nano-particulate semiconductor films. THE REVIEW OF SCIENTIFIC INSTRUMENTS 2019; 90:073905. [PMID: 31370435 DOI: 10.1063/1.5111418] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/26/2019] [Accepted: 07/10/2019] [Indexed: 06/10/2023]
Abstract
The transient grating (TG) imaging technique has been developed, where the refractive index change due to the photoexcited charge carriers excited with a stripe patterned light can be visualized. The spatiotemporal imaging of photoexcited charge carriers was demonstrated for a nanoparticulate TiO2 film. In the analytical procedures to map out the time constant distribution, the averaged response of photoexcited carriers in each image was obtained from the Fourier transform of the TG images since the image has a spatial modulation with a stripe pattern of light. The oscillation response due to the acoustic grating, the decay of the surface trapped electrons (until 1 μs), and thermal diffusion (until 100 µs) were observed. In order to obtain the lifetime imaging of the photoexcited electrons, the target time region (0-1 µs) for the response was selected and fitted with an exponential function, and the time constants were mapped out. We found that the time constants showed a wide range of distribution (68-920 ns), dependent on the sample positions.
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Affiliation(s)
- Makoto Ebihara
- Department of Applied Chemistry, Chuo University, Tokyo 112-8551, Japan
| | - Woon Yong Sohn
- Department of Applied Chemistry, Chuo University, Tokyo 112-8551, Japan
| | - Kenji Katayama
- Department of Applied Chemistry, Chuo University, Tokyo 112-8551, Japan
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19
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Gao H, Liu Y, Wang G, Li S, Han Z, Ren L. Switchable Wettability Surface with Chemical Stability and Antifouling Properties for Controllable Oil-Water Separation. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2019; 35:4498-4508. [PMID: 30845805 DOI: 10.1021/acs.langmuir.9b00094] [Citation(s) in RCA: 21] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/08/2023]
Abstract
Membrane materials with special wettability for separating oil-water mixtures have gradually become one of the research hotspots. However, oily wastewater usually has very strong corrosiveness, which puts forward high requirements for the chemical stability of the separation membrane. In addition, oil droplets may block the pores, resulting in the decrease of separation efficiency or even separation failure. Herein, biomimetic TiO2-titanium meshes (BTTMs) with switchable wettability were successfully fabricated by one-step dip coating of poly(vinylidene difluoride) and modified TiO2 suspension on the titanium meshes. The simple and efficient preparation method will facilitate the promotion of this smart material. Due to the controlled wettability, the BTTM can separate water or oil from an oil-water mixture as required. When the BTTM was immersed in strong corrosive solution or liquid nitrogen, the wettability did not change much, showing the good stability of the BTTM. Furthermore, the BTTM also has self-healing ability, self-recovery anti-oil-fouling properties, and self-cleaning behavior, which help it resist oil pollution and improve its recyclability. This study provides a simple and efficient strategy for fabricating a stable smart surface for on-demand controllable treatment of corrosive oily wastewater.
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