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Adamsen KC, Petrik NG, Dononelli W, Kimmel GA, Xu T, Li Z, Lammich L, Hammer B, Lauritsen JV, Wendt S. Origin of hydroxyl pair formation on reduced anatase TiO 2(101). Phys Chem Chem Phys 2023; 25:13645-13653. [PMID: 37145025 DOI: 10.1039/d3cp01051a] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/06/2023]
Abstract
The interaction of water with metal oxide surfaces is of key importance to several research fields and applications. Because of its ability to photo-catalyze water splitting, reducible anatase TiO2 (a-TiO2) is of particular interest. Here, we combine experiments and theory to study the dissociation of water on bulk-reduced a-TiO2(101). Following large water exposures at room temperature, point-like protrusions appear on the a-TiO2(101) surface, as shown by scanning tunneling microscopy (STM). These protrusions originate from hydroxyl pairs, consisting of terminal and bridging OH groups, OHt/OHb, as revealed by infrared reflection absorption spectroscopy (IRRAS) and valence band experiments. Utilizing density functional theory (DFT) calculations, we offer a comprehensive model of the water/a-TiO2(101) interaction. This model also explains why the hydroxyl pairs are thermally stable up to ∼480 K.
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Affiliation(s)
- Kræn C Adamsen
- Interdisciplinary Nanoscience Center (iNANO), Aarhus University, DK-8000 Aarhus C, Denmark.
| | - Nikolay G Petrik
- Physical Sciences Division, Pacific Northwest National Laboratory, Richland, Washington 99352, USA.
| | - Wilke Dononelli
- Department of Physics and Astronomy, Aarhus University, DK-8000 Aarhus C, Denmark
- MAPEX Center for Materials and Processes, Bremen Center for Computational Materials Science and Hybrid Materials Interfaces Group, Bremen University, 28359 Bremen, Germany
| | - Greg A Kimmel
- Physical Sciences Division, Pacific Northwest National Laboratory, Richland, Washington 99352, USA.
| | - Tao Xu
- Interdisciplinary Nanoscience Center (iNANO), Aarhus University, DK-8000 Aarhus C, Denmark.
| | - Zheshen Li
- Department of Physics and Astronomy, Aarhus University, DK-8000 Aarhus C, Denmark
| | - Lutz Lammich
- Interdisciplinary Nanoscience Center (iNANO), Aarhus University, DK-8000 Aarhus C, Denmark.
- Department of Physics and Astronomy, Aarhus University, DK-8000 Aarhus C, Denmark
| | - Bjørk Hammer
- Department of Physics and Astronomy, Aarhus University, DK-8000 Aarhus C, Denmark
| | - Jeppe V Lauritsen
- Interdisciplinary Nanoscience Center (iNANO), Aarhus University, DK-8000 Aarhus C, Denmark.
| | - Stefan Wendt
- Interdisciplinary Nanoscience Center (iNANO), Aarhus University, DK-8000 Aarhus C, Denmark.
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2
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Lin LY, Liu C, Dien Dang V, Fu HT. Atomically dispersed Ti-O clusters anchored on NH 2-UiO-66(Zr) as efficient and deactivation-resistant photocatalyst for abatement of gaseous toluene under visible light. J Colloid Interface Sci 2023; 635:323-335. [PMID: 36599234 DOI: 10.1016/j.jcis.2022.12.147] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2022] [Revised: 12/23/2022] [Accepted: 12/27/2022] [Indexed: 01/01/2023]
Abstract
Photocatalytic oxidation (PCO) of volatile organic compounds (VOCs) over MOF-based photocatalysts is considerably impeded by the weak activation of reactant molecules on the catalyst surface and low charge carrier mobility. In this study, we demonstrate that atomically dispersed Ti species anchored on NH2-UiO-66(Zr) (AUiO-66(Zr/Ti)) exhibit high visible-light-responsive photocatalytic activity toward toluene vapor with an 83 % removal efficiency and 89 % CO2 selectivity. These results are markedly superior to those reported in the literature. More importantly, AUiO-66(Zr/Ti) exhibited excellent catalytic stability during a prolonged reaction, while its pristine AUiO-66(Zr) counterpart underwent rapid catalytic deactivation after a few hours. The optimized sample, AUiO-66(Zr/Ti)-4h, provided extended visible light absorption and enhanced charge carrier mobility due to ligand-to-linker metal charge transfer. Meanwhile, the defect-rich surface of AUiO-66(Zr/Ti)-4h facilitated the activation of H2O/toluene molecules into the critical intermediates of hydroxyl, benzoic acid, and maleic anhydride, which were effectively converted under visible light illumination. On the basis of the combined results of the PCO of toluene and material characterization, the structure - activity relationship and the related catalytic mechanism are discussed comprehensively.
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Affiliation(s)
- Liang-Yi Lin
- Institute of Environmental Engineering, National Yang Ming Chiao Tung University, Hsinchu, Taiwan.
| | - Chieh Liu
- Institute of Environmental Engineering, National Yang Ming Chiao Tung University, Hsinchu, Taiwan
| | - Van Dien Dang
- Faculty of Biology and Environment, Ho Chi Minh City University of Food Industry, 140 Le Trong Tan, Ho Chi Minh 700000, Viet Nam
| | - Hsuan-Ting Fu
- Institute of Environmental Engineering, National Yang Ming Chiao Tung University, Hsinchu, Taiwan
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3
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Ma R, O'Connor CR, Collinge G, Allec SI, Lee MS, Dohnálek Z. The Role of Surface Hydroxyls in the Mobility of Carboxylates on Surfaces: Dynamics of Acetate on Anatase TiO 2(101). J Phys Chem Lett 2023; 14:2542-2550. [PMID: 36877161 DOI: 10.1021/acs.jpclett.3c00175] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/18/2023]
Abstract
The dynamics of reactive intermediates are important in catalysis for understanding transient species, which can drive reactivity and the transport of species to reaction centers. In particular, the interplay between surface-bound carboxylic acids and carboxylates is important for numerous chemical transformations, including CO2 hydrogenation and ketonization. Here, we investigate the dynamics of acetic acid on anatase TiO2(101) using scanning tunneling microscopy experiments and density functional theory calculations. We demonstrate the concomitant diffusion of bidentate acetate and a bridging hydroxyl and provide evidence for the transient formation of molecular monodentate acetic acid. The diffusion rate is strongly dependent on the position of hydroxyl and adjacent acetate(s). A facile three-step diffusion process is proposed consisting of acetate and hydroxyl recombination, acetic acid rotation, and acetic acid dissociation. This study clearly demonstrates that the dynamics of bidentate acetate could be important in forming monodentate species, which are proposed to drive selective ketonization.
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Affiliation(s)
- Runze Ma
- Physical and Computational Sciences Directorate and Institute for Integrated Catalysis, Pacific Northwest National Laboratory, Richland, Washington 99352, United States
| | - Christopher R O'Connor
- Physical and Computational Sciences Directorate and Institute for Integrated Catalysis, Pacific Northwest National Laboratory, Richland, Washington 99352, United States
| | - Gregory Collinge
- Physical and Computational Sciences Directorate and Institute for Integrated Catalysis, Pacific Northwest National Laboratory, Richland, Washington 99352, United States
| | - Sarah I Allec
- Physical and Computational Sciences Directorate and Institute for Integrated Catalysis, Pacific Northwest National Laboratory, Richland, Washington 99352, United States
| | - Mal-Soon Lee
- Physical and Computational Sciences Directorate and Institute for Integrated Catalysis, Pacific Northwest National Laboratory, Richland, Washington 99352, United States
| | - Zdenek Dohnálek
- Physical and Computational Sciences Directorate and Institute for Integrated Catalysis, Pacific Northwest National Laboratory, Richland, Washington 99352, United States
- Voiland School of Chemical Engineering and Bioengineering, Washington State University, Pullman, Washington 99163, United States
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4
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Pivotal role of oxygen during the synthesis of Cu(OH)2/TiO2 and its effect on photocatalytic hydrogen production activity. Catal Today 2023. [DOI: 10.1016/j.cattod.2023.01.014] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
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5
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Sustainable organic synthesis promoted on titanium dioxide using coordinated water and renewable energies/resources. Coord Chem Rev 2022. [DOI: 10.1016/j.ccr.2022.214773] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
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6
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Huang J, Liu S, Long W, Wang Q, Yu X, Li S. Highly enhanced photodegradation of emerging pollutants by Ag/AgCl/Ta2O5−x mesocrystals. Sep Purif Technol 2021. [DOI: 10.1016/j.seppur.2021.119733] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
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7
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Tang Y, Huang J, Liu S, Xiang D, Ma X, Yu X, Li M, Guo Q. Surface engineering induced superstructure Ta2O5−x mesocrystals for enhanced visible light photocatalytic antibiotic degradation. J Colloid Interface Sci 2021; 596:468-478. [DOI: 10.1016/j.jcis.2021.03.118] [Citation(s) in RCA: 19] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/25/2020] [Revised: 03/19/2021] [Accepted: 03/20/2021] [Indexed: 12/11/2022]
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8
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Mengting Z, Kurniawan TA, Avtar R, Othman MHD, Ouyang T, Yujia H, Xueting Z, Setiadi T, Iswanto I. Applicability of TiO 2(B) nanosheets@hydrochar composites for adsorption of tetracycline (TC) from contaminated water. JOURNAL OF HAZARDOUS MATERIALS 2021; 405:123999. [PMID: 33288338 DOI: 10.1016/j.jhazmat.2020.123999] [Citation(s) in RCA: 32] [Impact Index Per Article: 10.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/09/2019] [Revised: 09/12/2020] [Accepted: 09/14/2020] [Indexed: 06/12/2023]
Abstract
We test the feasibility of TiO2(B)@carbon composites as adsorbents, derived from wheat straws, for tetracycline (TC) adsorption from aqueous solutions. Hydrochar (HC), biochar (BC), and hydrochar-derived pyrolysis char (HDPC) are synthesized hydrothermally from the waste and then functionalized with TiO2(B), named as 'Composite-1', 'Composite-2', and 'Composite-3', respectively. A higher loading of TiO2(B) into the HC was also synthesized for comparison, named as 'Composite-4'. To compare their physico-chemical changes before and after surface modification, the composites are characterized using FESEM-EDS, XRD, BET, FRTEM, and FTIR. The effects of H2O2 addition on TC removal are investigated. Adsorption kinetics and isotherms of TC removal are studied, while TC adsorption mechanisms are elaborated. We found that the Composite-4 has the highest TC removal (93%) at pH 7, 1 g/L of dose, and 4 h of reaction time at 50 mg/L of TC after adding H2O2 (10 mM). The TC adsorption capacities of the Composite-1 and Composite-4 are 40.65 and 49.26 mg/g, respectively. The TC removal by the Composite-1 follows the pseudo-second order. Overall, this suggests that converting the wheat straw into HC and then functionalizing its surface with TiO2(B) as a composite has added values to the waste as an adsorbent for wastewater treatment.
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Affiliation(s)
- Zhu Mengting
- Key Laboratory of the Coastal and Wetland Ecosystems (Xiamen University), Ministry of Education, College of the Environment and Ecology, Xiamen University, Fujian 361102, China
| | - Tonni Agustiono Kurniawan
- Key Laboratory of the Coastal and Wetland Ecosystems (Xiamen University), Ministry of Education, College of the Environment and Ecology, Xiamen University, Fujian 361102, China; Department of Energy, Environment, and Climate Change, School of Environment Resources and Development (SERD), Asian Institute of Technology (AIT), Pathumthani 12120, Thailand.
| | - Ram Avtar
- Faculty of Environmental Earth Sciences, Hokkaido University, Sapporo 060-0810, Japan.
| | - Mohd Hafiz Dzarfan Othman
- Advanced Membrane Technology Research Centre (AMTEC), School of Chemical and Energy Engineering, University Teknologi Malaysia, 81310 Skudai, Johor, Malaysia
| | - Tong Ouyang
- Key Laboratory of the Coastal and Wetland Ecosystems (Xiamen University), Ministry of Education, College of the Environment and Ecology, Xiamen University, Fujian 361102, China
| | - Huang Yujia
- Key Laboratory of the Coastal and Wetland Ecosystems (Xiamen University), Ministry of Education, College of the Environment and Ecology, Xiamen University, Fujian 361102, China
| | - Zhang Xueting
- Key Laboratory of the Coastal and Wetland Ecosystems (Xiamen University), Ministry of Education, College of the Environment and Ecology, Xiamen University, Fujian 361102, China
| | - Tjandra Setiadi
- Center for Environment Studies, Bandung Institute of Technology (ITB), Bandung 40135, Indonesia
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9
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Soria FA, Di Valentin C. Reactive molecular dynamics simulations of hydration shells surrounding spherical TiO 2 nanoparticles: implications for proton-transfer reactions. NANOSCALE 2021; 13:4151-4166. [PMID: 33576363 DOI: 10.1039/d0nr07503e] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/11/2023]
Abstract
In many potential applications, nanoparticles are typically in an aqueous medium. This has strong influence on the stability, optical properties and reactivity, in particular for their functionalization. Therefore, the understanding of the chemistry at the interface between the solvent and the nanoparticle is of utmost importance. In this work, we present a comparative ReaxFF reactive molecular dynamics investigation on spherical TiO2 nanoparticles (NSs) of realistic size, with diameters from 2.2 to 4.4 nm, immersed in a large drop of bulk water. After force field validation for its use for a curved anatase TiO2 surface/water interface, we performed several simulations of the TiO2 nanoparticles of increasing size in a water drop. We found that water can be adsorbed jointly in a molecular and dissociative way on the surface. A Langmuir isotherm indicating an adsorption/desorption mechanism of water on the NS is observed. Regarding the dissociative adsorption, atomistic details reveal two different mechanisms, depending on the water concentration around the NS. At low coverage, the first mechanism involves direct dissociation of a single water molecule, whereas, at higher water coverage, the second mechanism is a proton transfer reaction involving two water molecules, also known as Grotthuss-like mechanism. Thermal annealing simulations show that several water molecules remain on the surface in agreement with the experimental reports. The capacity of adsorption is higher for the 2.2 and 3.0 nm NSs than for the 4.4 nm NS. Finally, a comparative investigation with flat surfaces indicates that NSs present a higher water adsorption capacity (undissociated and dissociated) than flat surfaces, which can be rationalized considering that NSs present many more low-coordinated Ti atoms available for water adsorption.
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Affiliation(s)
- Federico A Soria
- Dipartimento di Scienza dei Materiali, Università di Milano Bicocca, via R. Cozzi 55, 20125 Milano, Italy.
| | - Cristiana Di Valentin
- Dipartimento di Scienza dei Materiali, Università di Milano Bicocca, via R. Cozzi 55, 20125 Milano, Italy.
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10
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Enhancing hydrogen evolution reaction activity on cobalt oxide in alkaline electrolyte by doping inactive rare-earth metal. Electrochim Acta 2020. [DOI: 10.1016/j.electacta.2020.137230] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
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11
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Deskins NA, Kimmel GA, Petrik NG. Observation of Molecular Hydrogen Produced from Bridging Hydroxyls on Anatase TiO 2(101). J Phys Chem Lett 2020; 11:9289-9297. [PMID: 33090788 DOI: 10.1021/acs.jpclett.0c02735] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
Anatase TiO2 is used extensively in a wide range of catalytic and photocatalytic processes and is a promising catalyst for hydrogen production. Here, we show that molecular hydrogen was produced from bridging hydroxyls (HOb) on the (101) surface of single-crystal anatase (TiO2(101)). This stands in contrast to rutile TiO2(110), where HOb pairs react to form H2O. Electron bombardment at 30 K produced bridging oxygen vacancies in the surface. Deuterated bridging hydroxyls (DOb) were subsequently formed via dissociation of adsorbed D2O and confirmed by infrared reflection-absorption spectroscopy. During temperature-programmed desorption (TPD) spectroscopy, D2 desorption was observed at 520 K. Density functional theory calculations show that both H2 and H2O production from HOb are endothermic at 0 K on TiO2(101), but H2 (H2O) desorption is entropically driven above 230 K (800 K). The calculated activation barrier for H2 desorption is 1.40 eV, which is similar to the desorption energy obtained from analysis of the D2 TPD spectra. The H2 desorption likely proceeds in two steps: H atom diffusion on the surface and then recombination.
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Affiliation(s)
- N Aaron Deskins
- Department of Chemical Engineering, Worcester Polytechnic Institute, 100 Institute Road, Worcester, Massachusetts 01609, United States
| | - Greg A Kimmel
- Physical and Computational Sciences Directorate, Pacific Northwest National Laboratory, P.O. Box 999, Richland, Washington 99352, United States
| | - Nikolay G Petrik
- Physical and Computational Sciences Directorate, Pacific Northwest National Laboratory, P.O. Box 999, Richland, Washington 99352, United States
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12
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Lin LY, Liu C, Hsieh TT. Efficient visible and NIR light-driven photocatalytic CO2 reduction over defect-engineered ZnO/carbon dot hybrid and mechanistic insights. J Catal 2020. [DOI: 10.1016/j.jcat.2020.08.036] [Citation(s) in RCA: 22] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
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13
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Wu L, Fu C, Huang W. Surface chemistry of TiO 2 connecting thermal catalysis and photocatalysis. Phys Chem Chem Phys 2020; 22:9875-9909. [PMID: 32363360 DOI: 10.1039/c9cp07001j] [Citation(s) in RCA: 20] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
Chemical reactions catalyzed under heterogeneous conditions have recently expanded rapidly from traditional thermal catalysis to photocatalysis due to the rising concerns about sustainable development of energy and the environment. Adsorption of reactants on catalyst surfaces, subsequent surface reactions, and desorption of products from catalyst surfaces occur in both thermal catalysis and photocatalysis. TiO2 catalysts are widely used in thermal catalytic and photocatalytic reactions. Herein we review recent progress in surface chemistry, thermal catalysis and photocatalysis of TiO2 model catalysts from single crystals to nanocrystals with the aim of examining if the surface chemistry of TiO2 can bridge the fundamental understanding between thermal catalysis and photocatalysis. Following a brief introduction, the structures of major facets exposed on TiO2 catalysts, including surface reconstructions and defects, as well as the electronic structure and charge properties, are firstly summarized; then the recent progress in adsorption, thermal chemistry and photochemistry of small molecules on TiO2 single crystals and nanocrystals is comprehensively reviewed, focusing on manifesting the structure-(photo)activity relations and the commonalities/differences between thermal catalysis and photocatalysis; and finally concluding remarks and perspectives are given.
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Affiliation(s)
- Longxia Wu
- Hefei National Laboratory for Physical Sciences at the Microscale, Key Laboratory of Surface and Interface Chemistry and Energy Catalysis of Anhui Higher Education Institutes and Department of Chemical Physics, University of Science and Technology of China, Hefei 230026, P. R. China.
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14
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Recent Advancements in the Understanding of the Surface Chemistry in TiO2 Photocatalysis. SURFACES 2020. [DOI: 10.3390/surfaces3010008] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
Surface chemistry plays a major role in photocatalytic and photoelectrochemical processes taking place with the participation of TiO2. The synthesis methods, surface characterizations, theoretical research methods, and hardware over the last decade generated opportunities for progress in the surface science of this photocatalyst. Very recently, attention was paid to the design of photocatalysts at the nanoscale level by adjusting the types of exposed surfaces and their ratio, the composition and the surface structure of nanoparticles, and that of individual surfaces. The current theoretical methods provide highly detailed designs that can be embodied experimentally. The present review article describes the progress in the surface science of TiO2 and TiO2-based photocatalysts obtained over the last three years. Such aspects including the properties of macro- and nano-scale surfaces, noble-metal-loaded surfaces, doping with Mg and S, intrinsic defects (oxygen vacancies), adsorption, and photoreactions are considered. The main focus of the article is on the anatase phase of TiO2.
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15
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Wang B, Li X, Liang S, Chu R, Zhang D, Chen H, Wang M, Zhou S, Chen W, Cao X, Feng W. Adsorption and oxidation of SO2 on the surface of TiO2 nanoparticles: the role of terminal hydroxyl and oxygen vacancy–Ti3+ states. Phys Chem Chem Phys 2020; 22:9943-9953. [DOI: 10.1039/d0cp00785d] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
The absorption and oxidation reactions of SO2 on TiO2 nanoparticles were investigated by using a flow chamber, synchrotron X-ray absorption near-edge structure and high resolution synchrotron X-ray photoelectron spectroscopy techniques.
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16
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Polarization and Trap Characteristics Modification of Oil-Impregnated Paper Insulation by TiO₂ Nanoparticles. NANOMATERIALS 2019; 9:nano9020174. [PMID: 30708942 PMCID: PMC6410272 DOI: 10.3390/nano9020174] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 01/07/2019] [Revised: 01/21/2019] [Accepted: 01/29/2019] [Indexed: 11/17/2022]
Abstract
Polarization and traps determine the electrical property of oil-paper insulation, but most attention has been paid to the modification of insulating oil with nanoparticles, so there are is little research about oil-impregnated paper, and the origin for performance variation is not understood yet. In this paper, spherical nanoscale titanium dioxide was prepared by the hydrolysis method and nanofluid-impregnated paper (NP) was fabricated through oil-impregnation. The frequency domain spectrum was measured for polarization analysis, and both thermally stimulated depolarization current (TSDC) and isothermal surface potential decay (ISPD) methods were used to reveal trap parameters. Results show that NP's low frequency permittivity is much larger, and another peak appears in the spectrum even though the content of nanoparticles is very low. With the addition of TiO₂ nanoparticles, TSDC's amplitude and peak temperature increase, and the trap energy becomes shallower. TiO₂ nanoparticles' strong polarization and high activation energy contribute to NP's larger interface polarization intensity and activation energy. Furthermore, because of oxygen vacancies, TiO₂ nanoparticles offer a transfer site for holes and electrons to escape from deep traps; thus, the trap energy is greatly reduced.
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17
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Liu X, Hu Q, Zhu B, Li G, Fan L, Chai X, Zhang Q, Liu J, He C. Boosting Electrochemical Hydrogen Evolution of Porous Metal Phosphides Nanosheets by Coating Defective TiO 2 Overlayers. SMALL (WEINHEIM AN DER BERGSTRASSE, GERMANY) 2018; 14:e1802755. [PMID: 30260576 DOI: 10.1002/smll.201802755] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/15/2018] [Revised: 08/12/2018] [Indexed: 06/08/2023]
Abstract
Nonprecious transition metal phosphides (TMPs) have emerged as robust electrocalysts for the hydrogen evolution reaction (HER). However, the TMPs suffer from low activity for water dissociation, which greatly limits the efficiency for alkaline HER. Here, a facile yet robust strategy is reported to boost the HER of metal phosphides by coating defective TiO2 overlayers. The oxygen vacancies (Ov ) on defective TiO2 overlayers are found to possess high activity for adsorption and dissociation of water, thereby significantly promoting the initial Volmer step of HER to generate the reactive hydrogen atoms. Moreover, the porous (Co, Ni)2 P (i.e., Co2 P and Ni2 P) nanosheets provide enough active sites for adsorption and recombination of reactive hydrogen atoms to produce hydrogen gas. The catalytic synergy of (Co, Ni)2 P and Ov coupled with the hierarchically porous structure renders the porous (Co, Ni)2 P@0.1TiO2 nanosheet arrays excellent electrocatalysts for HER, showing a small overpotential (92 mV) to yield a current density of 10 mA cm-2 , a small Tafel slope (49 mV dec-1 ), and an outstanding stability. This work demonstrates a surface decoration route for enhancing the activity of nonprecious metal-based electrocatalysts for HER.
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Affiliation(s)
- Xiufang Liu
- College of Chemistry and Environmental Engineering, Shenzhen University, Shenzhen, Guangdong, 518060, P. R. China
| | - Qi Hu
- College of Chemistry and Environmental Engineering, Shenzhen University, Shenzhen, Guangdong, 518060, P. R. China
| | - Bin Zhu
- College of Chemistry and Environmental Engineering, Shenzhen University, Shenzhen, Guangdong, 518060, P. R. China
| | - Guomin Li
- College of Chemistry and Environmental Engineering, Shenzhen University, Shenzhen, Guangdong, 518060, P. R. China
| | - Liangdong Fan
- College of Chemistry and Environmental Engineering, Shenzhen University, Shenzhen, Guangdong, 518060, P. R. China
| | - Xiaoyan Chai
- College of Chemistry and Environmental Engineering, Shenzhen University, Shenzhen, Guangdong, 518060, P. R. China
| | - Qianling Zhang
- College of Chemistry and Environmental Engineering, Shenzhen University, Shenzhen, Guangdong, 518060, P. R. China
| | - Jianhong Liu
- College of Chemistry and Environmental Engineering, Shenzhen University, Shenzhen, Guangdong, 518060, P. R. China
| | - Chuanxin He
- College of Chemistry and Environmental Engineering, Shenzhen University, Shenzhen, Guangdong, 518060, P. R. China
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18
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Nadeem I, Treacy JPW, Selcuk S, Torrelles X, Hussain H, Wilson A, Grinter DC, Cabailh G, Bikondoa O, Nicklin C, Selloni A, Zegenhagen J, Lindsay R, Thornton G. Water Dissociates at the Aqueous Interface with Reduced Anatase TiO 2 (101). J Phys Chem Lett 2018; 9:3131-3136. [PMID: 29768922 PMCID: PMC5994726 DOI: 10.1021/acs.jpclett.8b01182] [Citation(s) in RCA: 27] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2018] [Accepted: 05/16/2018] [Indexed: 05/22/2023]
Abstract
Elucidating the structure of the interface between natural (reduced) anatase TiO2 (101) and water is an essential step toward understanding the associated photoassisted water splitting mechanism. Here we present surface X-ray diffraction results for the room temperature interface with ultrathin and bulk water, which we explain by reference to density functional theory calculations. We find that both interfaces contain a 25:75 mixture of molecular H2O and terminal OH bound to titanium atoms along with bridging OH species in the contact layer. This is in complete contrast to the inert character of room temperature anatase TiO2 (101) in ultrahigh vacuum. A key difference between the ultrathin and bulk water interfaces is that in the latter water in the second layer is also ordered. These molecules are hydrogen bonded to the contact layer, modifying the bond angles.
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Affiliation(s)
- Immad
M. Nadeem
- London
Centre for Nanotechnology and Department of Chemistry, University College London, 20 Gordon Street, London, WC1H 0AJ, United Kingdom
- Diamond
Light Source Ltd, Harwell Science and Innovation
Campus, Didcot, Oxfordshire OX11 0DE, United Kingdom
| | - Jon P. W. Treacy
- Corrosion
and Protection Centre, School of Materials, The University of Manchester, Sackville Street, Manchester M13 9PL, United Kingdom
| | - Sencer Selcuk
- Department
of Chemistry, Princeton University, Princeton, New Jersey 08540, United States
| | - Xavier Torrelles
- Institut
de Ciència de Materials de Barcelona (CSIC), Campus UAB, 08193 Bellaterra, Spain
| | - Hadeel Hussain
- Corrosion
and Protection Centre, School of Materials, The University of Manchester, Sackville Street, Manchester M13 9PL, United Kingdom
| | - Axel Wilson
- London
Centre for Nanotechnology and Department of Chemistry, University College London, 20 Gordon Street, London, WC1H 0AJ, United Kingdom
| | - David C. Grinter
- London
Centre for Nanotechnology and Department of Chemistry, University College London, 20 Gordon Street, London, WC1H 0AJ, United Kingdom
| | - Gregory Cabailh
- Sorbonne Université,
CNRS, UMR 7588, Institut des NanoSciences de Paris, 4 Place Jussieu, F-75005 Paris, France
| | - Oier Bikondoa
- Department
of Physics, University of Warwick, Gibbet Hill Road, Coventry CV4 7AL, United Kingdom
- XMaS,
the U.K. CRG Beamline, ESRF, The European Synchrotron, 71, Avenue des Martyrs, CS40220, F-38043 Grenoble Cedex 09, France
| | - Christopher Nicklin
- Diamond
Light Source Ltd, Harwell Science and Innovation
Campus, Didcot, Oxfordshire OX11 0DE, United Kingdom
| | - Annabella Selloni
- Department
of Chemistry, Princeton University, Princeton, New Jersey 08540, United States
| | - Jörg Zegenhagen
- Diamond
Light Source Ltd, Harwell Science and Innovation
Campus, Didcot, Oxfordshire OX11 0DE, United Kingdom
| | - Robert Lindsay
- Corrosion
and Protection Centre, School of Materials, The University of Manchester, Sackville Street, Manchester M13 9PL, United Kingdom
| | - Geoff Thornton
- London
Centre for Nanotechnology and Department of Chemistry, University College London, 20 Gordon Street, London, WC1H 0AJ, United Kingdom
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