101
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Goodall JBM, Kellici S, Illsley D, Lines R, Knowles JC, Darr JA. Optical and photocatalytic behaviours of nanoparticles in the Ti–Zn–O binary system. RSC Adv 2014. [DOI: 10.1039/c3ra48030e] [Citation(s) in RCA: 42] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
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102
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Clawin PM, Friend CM, Al-Shamery K. Defects in surface chemistry--reductive coupling of benzaldehyde on rutile TiO₂(110). Chemistry 2014; 20:7665-9. [PMID: 24825761 DOI: 10.1002/chem.201402102] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2014] [Indexed: 11/11/2022]
Abstract
The surface chemistry of oxygen and oxygenates on Rutile TiO2(110) is of great interest for various applications such as heterogeneous catalysis and photo catalysis. Though it is generally accepted that surface defects are active sites, the role of subsurface defects is under debate. We have therefore investigated the influence of the bulk defect density on the reductive coupling of benzaldehyde to stilbene as a model system. Using IRRAS we identify stilbene diolate as a reduction intermediate. The concentration of this intermediate is proportional to the bulk defect density, whereas adsorption of benzaldehyde at lower temperatures is not affected, which indicates a dominant role of Ti interstitials at temperatures above 400 K.
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Affiliation(s)
- Peter M Clawin
- Institute for Chemistry, Carl von Ossietzky University of Oldenburg, Carl von Ossietzky Strasse 9-11, 26129 Oldenburg (Germany), Fax: (+49) 441 709 2809
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103
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Dogan F, Chao S, Peng J, Greenbaum SG. Vanadium Doped Nanostructured TiO2 Dielectrics. ACTA ACUST UNITED AC 2014. [DOI: 10.1557/opl.2014.256] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
ABSTRACTDielectric properties of titanium oxide ceramics are strongly influenced by the microstructural features and concentration of dopants and impurity ions. Electrical conductivity (via insulation resistance) of vanadium doped nanostructured titanium dioxide (TiO2) ceramics was measured as a function of donor concentration and temperature. In order to further clarify the effect of the dopants on the microstructural development and resultant dielectric properties of TiO2, electron paramagnetic resonance (EPR) spectroscopy was employed. Vanadium-doped TiO2 exhibited well-defined hyperfine splitting characteristics of the 51V nuclei indicating that the dopant ions are dispersed within the grains and not preferentially segregated at the grain boundaries.
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104
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Petrella A, Boghetich G, Petrella M, Mastrorilli P, Petruzzelli V, Petruzzelli D. Photocatalytic Degradation of Azo Dyes. Pilot Plant Investigation. Ind Eng Chem Res 2014. [DOI: 10.1021/ie403506s] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Andrea Petrella
- Dipartimento di Ingegneria
Civile, Ambientale, del Territorio, Edile e di Chimica (DICATECh), Politecnico di Bari, 4, Via E. Orabona, 70125 Bari, Italy
| | - Giancarlo Boghetich
- Dipartimento di Ingegneria
Civile, Ambientale, del Territorio, Edile e di Chimica (DICATECh), Politecnico di Bari, 4, Via E. Orabona, 70125 Bari, Italy
| | - Mario Petrella
- Dipartimento di Ingegneria
Civile, Ambientale, del Territorio, Edile e di Chimica (DICATECh), Politecnico di Bari, 4, Via E. Orabona, 70125 Bari, Italy
| | - Piero Mastrorilli
- Dipartimento di Ingegneria
Civile, Ambientale, del Territorio, Edile e di Chimica (DICATECh), Politecnico di Bari, 4, Via E. Orabona, 70125 Bari, Italy
| | - Valentina Petruzzelli
- Dipartimento di Ingegneria
Civile, Ambientale, del Territorio, Edile e di Chimica (DICATECh), Politecnico di Bari, 4, Via E. Orabona, 70125 Bari, Italy
| | - Domenico Petruzzelli
- Dipartimento di Ingegneria
Civile, Ambientale, del Territorio, Edile e di Chimica (DICATECh), Politecnico di Bari, 4, Via E. Orabona, 70125 Bari, Italy
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105
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Cho IS, Logar M, Lee CH, Cai L, Prinz FB, Zheng X. Rapid and controllable flame reduction of TiO2 nanowires for enhanced solar water-splitting. NANO LETTERS 2014; 14:24-31. [PMID: 24295287 DOI: 10.1021/nl4026902] [Citation(s) in RCA: 69] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/20/2023]
Abstract
We report a new flame reduction method to generate controllable amount of oxygen vacancies in TiO2 nanowires that leads to nearly three times improvement in the photoelectrochemical (PEC) water-splitting performance. The flame reduction method has unique advantages of a high temperature (>1000 °C), ultrafast heating rate, tunable reduction environment, and open-atmosphere operation, so it enables rapid formation of oxygen vacancies (less than one minute) without damaging the nanowire morphology and crystallinity and is even applicable to various metal oxides. Significantly, we show that flame reduction greatly improves the saturation photocurrent densities of TiO2 nanowires (2.7 times higher), α-Fe2O3 nanowires (9.4 times higher), ZnO nanowires (2.0 times higher), and BiVO4 thin film (4.3 times higher) in comparison to untreated control samples for PEC water-splitting applications.
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Affiliation(s)
- In Sun Cho
- Department of Mechanical Engineering, Stanford University , California 94305, United States
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106
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Abstract
AbstractNanoparticles of nitrogen-modified TiO2 (N-doped TiO2) calcined at 300°C and 350°C, have been prepared with and without water rinsing. Samples were characterized by x-ray diffractrometry (XRD) and optical spectroscopy. The electron paramagnetic resonance (EPR) spectra from centers involving oxygen vacancies were recorded for all samples. These could be attributed to paramagnetic surface centers of the hole type, for example to paramagnetic oxygen radicals O−, O2−etc. The concentration of these centers increased after water rising and it further increased for samples annealed at higher temperature. Additionally, for samples calcined at 300°C, and calcined at 350°C and rinsed, the EPR spectra evidenced the presence of magnetic clusters of Ti3+ ions. The photocatalytic activity of samples was studied towards phenol decomposition under unltraviolet-visible (UV-Vis) irradiation. It was found that, in comparison to the starting materials, the rinsed materials showed increased photocatalytic activity towards phenol oxidation. The light absorption (UV-Vis/DRS) as well as surface Fourier transform infrared/diffuse reflectance spectroscopy (FTIR/DR) studies confirmed a significantly enhanced light absorption and the presence of nitrogen groups on the photocatalysts surfaces, respectively. A significant increase of concentration of paramagnetic centers connected with oxygen vacancies after water rising has had an essential influence on increasing their photocatalytic activity.
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107
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Li RZ, Xu HG, Cao GJ, Xu XL, Zheng WJ. Interaction of TiO2(-) with water: photoelectron spectroscopy and density functional calculations. J Chem Phys 2013; 139:184303. [PMID: 24320270 DOI: 10.1063/1.4828815] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
The interactions of titania with water molecules were studied via photoelectron spectroscopy and density functional calculations of TiO(OH)2(-) and Ti(OH)4(H2O)n(-) (n = 0-5) clusters which are corresponding to the TiO2(H2O)(-) and TiO2(H2O)n+2(-) (n = 0-5) systems, respectively. Experimental observation and theoretical calculations confirmed that TiO(OH)2(-) was produced when TiO2(-) interacts with one water molecule, and Ti(OH)4(H2O)n(-) (n = 0-5) were produced successively when TiO2(-) interacts with two or more water molecules. The structures of Ti(OH)4(H2O)n(-) with n = 4, 5 are slightly different from those of n = 1-3. The structures of Ti(OH)4(H2O)1-3(-) can be viewed as the water molecules interacting with the Ti(OH)4(-) core through hydrogen bonds; however, in Ti(OH)4(H2O)4,5(-), one of the water molecules interacts directly with the Ti atom via its oxygen atom instead of a hydrogen bond and distorted the Ti(OH)4(-) core.
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Affiliation(s)
- Ren-Zhong Li
- College of Electronics and Information, Xi'an Polytechnic University, Xi'an 710048, China
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108
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Topalian Z, Stefanov B, Granqvist C, Österlund L. Adsorption and photo-oxidation of acetaldehyde on TiO2 and sulfate-modified TiO2: Studies by in situ FTIR spectroscopy and micro-kinetic modeling. J Catal 2013. [DOI: 10.1016/j.jcat.2013.08.004] [Citation(s) in RCA: 48] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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109
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Yu X, Kim B, Kim YK. Highly Enhanced Photoactivity of Anatase TiO2 Nanocrystals by Controlled Hydrogenation-Induced Surface Defects. ACS Catal 2013. [DOI: 10.1021/cs4005776] [Citation(s) in RCA: 286] [Impact Index Per Article: 26.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Affiliation(s)
- Xiaomei Yu
- Department of Energy Systems
Research and Department of Chemistry, Ajou University, Suwon 443-749, South Korea
| | - Boseong Kim
- Department of Energy Systems
Research and Department of Chemistry, Ajou University, Suwon 443-749, South Korea
| | - Yu Kwon Kim
- Department of Energy Systems
Research and Department of Chemistry, Ajou University, Suwon 443-749, South Korea
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110
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Yang Y, Ling Y, Wang G, Li Y. The Effect of the Hydrogenation Temperature on TiO2Nanostructures for Photoelectrochemical Water Oxidation. Eur J Inorg Chem 2013. [DOI: 10.1002/ejic.201300760] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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111
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Mwangi IW, Ngila JC, Ndungu P, Msagati TAM, Kamau JN. Immobilized Fe (III)-doped titanium dioxide for photodegradation of dissolved organic compounds in water. ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH INTERNATIONAL 2013; 20:6028-6038. [PMID: 23526310 DOI: 10.1007/s11356-013-1600-6] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/01/2012] [Accepted: 02/25/2013] [Indexed: 06/02/2023]
Abstract
Photocatalytic degradation of dissolved organic carbon (DOC) by utilizing Fe(III)-doped TiO2 at the visible radiation range is hereby reported. The photocatalyst was immobilized on sintered glass frits with the coating done by wet method, calcinated at 500 °C and then applied in a photodegradation reactor. The addition of a transition metal dopant, Fe(III), initiated the red shift which was confirmed by UV-Vis spectroscopy, and the photocatalyst was activated by visible radiation. X-ray diffraction patterns showed that Fe(III) doping had an effect on the crystallinity of the photocatalysts. Mixtures of DOC and associated coloured solutions were degraded in first-order kinetics, showing that the degradation process was not dependent on intermediates or other species in solution. A reactor with a catalyst coating area of 12.57 cm(2) was able to degrade 0.623 mg of the dissolved material per minute. Exposure of the reactor to hostile acidic conditions and repeated use did not compromise its efficiency. It was observed that the reactor regenerates itself in the presence of visible light, and therefore, it can be re-used for more than 100 runs before the performance dropped to <95 %. The results obtained indicate that the photocatalyst reactor has a great potential of application for use in tandem with biosorbent cartridges to complement water purification methods for domestic consumption.
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Affiliation(s)
- Isaac W Mwangi
- Department of Applied Chemistry, University of Johannesburg, Doornfontein Campus, Doornfontein, P.O Box 17011, 2028, Johannesburg, South Africa
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112
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Park SJ, Lee JP, Jang JS, Rhu H, Yu H, You BY, Kim CS, Kim KJ, Cho YJ, Baik S, Lee W. In situ control of oxygen vacancies in TiO₂ by atomic layer deposition for resistive switching devices. NANOTECHNOLOGY 2013; 24:295202. [PMID: 23799660 DOI: 10.1088/0957-4484/24/29/295202] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/02/2023]
Abstract
Oxygen vacancies (V(O)) have profound effects on the physical and chemical performance of devices based on oxide materials. This is particularly true in the case of oxide-based resistive random access memories, in which memory switching operation under an external electrical stimulus is closely associated with the migration and ordering of the oxygen vacancies in the oxide material. In this paper, we report on a reliable approach to in situ control of the oxygen vacancies in TiOx films. Our strategy for tight control of the oxygen vacancy is based on the utilization of plasma-enhanced atomic layer deposition of titanium oxide under precisely regulated decomposition of the precursor molecules (titanium (IV) tetraisopropoxide, Ti[OCH(CH₃)₂]₄) by plasma-activated reactant mixture (N₂+O₂). From the various spectroscopic and microstructural analyses by using Rutherford backscattering spectrometry, x-ray photoelectron spectroscopy, high-resolution transmission electron microscopy, confocal Raman spectroscopy, and spectroscopic ellipsometry, we found that the precursor decomposition power (R(F)) of plasma-activated reactant mixture determines not only the oxygen vacancy concentration but also the crystallinity of the resulting TiO(x) film: nanocrystalline anatase TiO(x) with fewer oxygen vacancies under high R(F), while amorphous TiOx with more oxygen vacancies under low RF. Enabled by our controlling capability over the oxygen vacancy concentration, we were able to thoroughly elucidate the effect of oxygen vacancies on the resistive switching behavior of TiO(x)-based memory capacitors (Pt/TiO(x)/Pt). The electrical conduction behavior at the high resistance state could be explained within the framework of the trap-controlled space-charge-limited conduction with two characteristic transition voltages. One is the voltage (V(SCL)) for the transition from Ohmic conduction to space-charge-limited conduction, and the other is the voltage (V(TFL)) for transition from space-charge-limited conduction to trap-filled-limited conduction. In this work, we have disclosed for the first time the dependence of these two characteristic transition voltages (i.e., V(SCL) and V(TFL)) on the oxygen vacancy concentration.
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Affiliation(s)
- Sang-Joon Park
- Korea Research Institute of Standards and Science-KRISS, Yuseong, Daejeon 305-340, Korea
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113
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Dholabhai PP, Yu HG. Electronic structure and quantum dynamics of photoinitiated dissociation of O2 on rutile TiO2 nanocluster. J Chem Phys 2013; 138:194705. [DOI: 10.1063/1.4805000] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022] Open
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114
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Pang CL, Lindsay R, Thornton G. Structure of clean and adsorbate-covered single-crystal rutile TiO2 surfaces. Chem Rev 2013; 113:3887-948. [PMID: 23676004 DOI: 10.1021/cr300409r] [Citation(s) in RCA: 264] [Impact Index Per Article: 24.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Affiliation(s)
- Chi Lun Pang
- London Centre for Nanotechnology and Department of Chemistry, University College London, London WC1H 0AJ, United Kingdom
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115
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Pan X, Yang MQ, Fu X, Zhang N, Xu YJ. Defective TiO2 with oxygen vacancies: synthesis, properties and photocatalytic applications. NANOSCALE 2013; 5:3601-14. [PMID: 23532413 DOI: 10.1039/c3nr00476g] [Citation(s) in RCA: 768] [Impact Index Per Article: 69.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
Titanium dioxide (TiO2), as an important semiconductor metal oxide, has been widely investigated in the field of photocatalysis. The properties of TiO2, including its light absorption, charge transport and surface adsorption, are closely related to its defect disorder, which in turn plays a significant role in the photocatalytic performance of TiO2. Among all the defects identified in TiO2, oxygen vacancy is one of the most important and is supposed to be the prevalent defect in many metal oxides, which has been widely investigated both by theoretical calculations and experimental characterizations. Here, we give a short review on the existing strategies for the synthesis of defective TiO2 with oxygen vacancies, and the defect related properties of TiO2 including structural, electronic, optical, dissociative adsorption and reductive properties, which are intimately related to the photocatalytic performance of TiO2. In particular, photocatalytic applications with regard to defective TiO2 are outlined. In addition, we offer some perspectives on the challenge and new direction for future research in this field. We hope that this tutorial minireview would provide some useful contribution to the future design and fabrication of defective semiconductor-based nanomaterials for diverse photocatalytic applications.
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Affiliation(s)
- Xiaoyang Pan
- State Key Laboratory Breeding Base of Photocatalysis, College of Chemistry and Chemical Engineering, Fuzhou University, Fuzhou 350002, PR China
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116
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Freeman R, Girsh J, Willner I. Nucleic acid/quantum dots (QDs) hybrid systems for optical and photoelectrochemical sensing. ACS APPLIED MATERIALS & INTERFACES 2013; 5:2815-2834. [PMID: 23425022 DOI: 10.1021/am303189h] [Citation(s) in RCA: 134] [Impact Index Per Article: 12.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/01/2023]
Abstract
Nucleic acid/semiconductor quantum dots (QDs) hybrid systems combine the recognition and catalytic properties of nucleic acids with the unique photophysical features of QDs. These functions of nucleic acid/QDs hybrids are implemented to develop different optical sensing platforms for the detection of DNA, aptamer-substrate complexes, and metal ions. Different photophysical mechanisms including fluorescence, electron transfer quenching, fluorescence resonance energy transfer (FRET), and chemiluminescence resonance energy transfer (CRET) are used to develop the sensor systems. The size-controlled luminescence properties of QDs are further implemented for the multiplexed, parallel analysis of several DNAs, aptamer-substrate complexes, or mixtures of ions. Similarly, methods to amplify the sensing events through the biocatalytic regeneration of the analyte were developed. An additional paradigm in the implementation of nucleic acid/QDs hybrids for sensing applications involves the integration of the systems with electrodes, and the generation of photocurrents as transduction signals for the sensing events. Finally, semiconductor QDs conjugated to functional DNA machines, such as "walker" systems, provide an effective optical label for probing the dynamics and mechanical functions of the molecular devices. The present article addresses the recent advances in the application of nucleic acid/QDs hybrids for sensing applications and DNA nanotechnology, and discusses future perspectives of these hybrid materials.
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Affiliation(s)
- Ronit Freeman
- Institute of Chemistry, Center for Nanoscience and Nanotechnologhy, The Hebrew University of Jerusalem, Jerusalem 91904, Israel
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117
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Henderson MA, Lyubinetsky I. Molecular-Level Insights into Photocatalysis from Scanning Probe Microscopy Studies on TiO2(110). Chem Rev 2013; 113:4428-55. [DOI: 10.1021/cr300315m] [Citation(s) in RCA: 204] [Impact Index Per Article: 18.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Affiliation(s)
- Michael A. Henderson
- Physical Sciences Division, Pacific Northwest National Laboratory, P.O. Box 999,
MS K8-87 Richland, Washington 99352, United States
| | - Igor Lyubinetsky
- Environmental Molecular Sciences
Laboratory, Pacific Northwest National Laboratory, P.O. Box 999, MS K8-93 Richland, Washington 99352, United States
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118
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119
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Ma Z, Zhou C, Mao X, Ren Z, Dai D, Yang X. Kinetics and Dynamics of Photocatalyzed Dissociation of Ethanol on TiO2(110). CHINESE J CHEM PHYS 2013. [DOI: 10.1063/1674-0068/26/01/1-7] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022]
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120
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Xu H, Ouyang S, Li P, Kako T, Ye J. High-active anatase TiO₂ nanosheets exposed with 95% {100} facets toward efficient H₂ evolution and CO₂ photoreduction. ACS APPLIED MATERIALS & INTERFACES 2013; 5:1348-1354. [PMID: 23360579 DOI: 10.1021/am302631b] [Citation(s) in RCA: 87] [Impact Index Per Article: 7.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/27/2023]
Abstract
We succeed in preparation of anatase TiO₂ single crystals with marked photocatalytic activity via a facile and effective method. This TiO₂ is composed of TiO₂ ultrathin nanosheets (2 nm in thickness) with 95% of exposed {100} facet, which is considered to be the active facet for photocatalytic reaction. This percentage (95%) is the highest among previously reported {100} facet exposed anatase TiO₂. More importantly, due to this high ratio, our developed TiO₂ nanosheets showed marked photocatalytic activity, about 5 times higher activity in both H₂ evolution and CO₂ reduction than the reference sample, TiO₂ cuboids with 53% of exposed {100} facet. For the TiO₂ nanosheets, both the higher percentage of exposed {100} facets and larger surface area can offer more surface active sites in the photocatalytic reaction. On the other hand, the superior electronic band structure which results from the higher percentage of {100} facet is also beneficial for the higher activity. This study exemplifies that the facet engineering of semiconductors is one of the most effective strategies to achieve advanced properties over photofunctional materials for solar energy conversion.
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Affiliation(s)
- Hua Xu
- Graduate School of Chemical Science and Engineering, Hokkaido University, Sapporo 060-0814, Japan
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121
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Yu J, Li Q, Liu S, Jaroniec M. Ionic-Liquid-Assisted Synthesis of Uniform Fluorinated B/C-Codoped TiO2Nanocrystals and Their Enhanced Visible-Light Photocatalytic Activity. Chemistry 2013; 19:2433-41. [DOI: 10.1002/chem.201202778] [Citation(s) in RCA: 139] [Impact Index Per Article: 12.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2012] [Revised: 11/06/2012] [Indexed: 11/08/2022]
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122
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Van Heetvelde P, Beyers E, Wyns K, Adriaensens P, Maes BUW, Mullens S, Buekenhoudt A, Meynen V. A new method to graft titania using Grignard reagents. Chem Commun (Camb) 2013; 49:6998-7000. [DOI: 10.1039/c3cc43695k] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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123
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Dillon RJ, Joo JB, Zaera F, Yin Y, Bardeen CJ. Correlating the excited state relaxation dynamics as measured by photoluminescence and transient absorption with the photocatalytic activity of Au@TiO2core–shell nanostructures. Phys Chem Chem Phys 2013; 15:1488-96. [DOI: 10.1039/c2cp43666c] [Citation(s) in RCA: 61] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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124
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Li Z, Kay BD, Dohnálek Z. Dehydration and dehydrogenation of ethylene glycol on rutile TiO2(110). Phys Chem Chem Phys 2013; 15:12180-6. [DOI: 10.1039/c3cp50687h] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Affiliation(s)
- Zhenjun Li
- Physical Sciences Directorate and Institute for Integrated Catalysis, Pacific Northwest National Laboratory, P.O. Box 999, Richland, WA 99352, USA
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125
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Autin O, Hart J, Jarvis P, MacAdam J, Parsons SA, Jefferson B. Comparison of UV/H2O2 and UV/TiO2 for the degradation of metaldehyde: Kinetics and the impact of background organics. WATER RESEARCH 2012; 46:5655-5662. [PMID: 22901408 DOI: 10.1016/j.watres.2012.07.057] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/24/2012] [Revised: 07/20/2012] [Accepted: 07/28/2012] [Indexed: 06/01/2023]
Abstract
The kinetics of photodegradation of the pesticide metaldehyde by UV/H(2)O(2) and UV/TiO(2) in laboratory grade water and a natural surface water were studied. Experiments were carried out in a bench scale collimated beam device using UVC radiation. Metaldehyde was efficiently degraded by both processes in laboratory grade water at identical rates of degradation (0.0070 and 0.0067 cm(2) mJ(-1) for UV/TiO(2) and UV/H(2)O(2) respectively) when optimised doses were used. The ratio between oxidant and metaldehyde was significantly higher for H(2)O(2) due to its low photon absorption efficiency at 254 nm. However, the presence of background organic compounds in natural water severely affected the rate of degradation, and whilst the pseudo first-order rate constant of degradation by UV/H(2)O(2) was slowed down (0.0020 cm(2) mJ(-1)), the degradation was completely inhibited for the UV/TiO(2) process (k' = 0.00007 cm(2) mJ(-1)) due to the blockage of active sites on TiO(2) surface by the background organic material.
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Affiliation(s)
- Olivier Autin
- Cranfield Water Science Institute, Department of Environmental Science and Technology, Cranfield University, Bedfordshire MK43 0AL, UK
| | - Julie Hart
- Severn Trent Water LTD., Severn Trent Centre, PO Box 5309, Coventry CV3 9FH, West Midlands, UK
| | - Peter Jarvis
- Cranfield Water Science Institute, Department of Environmental Science and Technology, Cranfield University, Bedfordshire MK43 0AL, UK
| | - Jitka MacAdam
- Cranfield Water Science Institute, Department of Environmental Science and Technology, Cranfield University, Bedfordshire MK43 0AL, UK
| | - Simon A Parsons
- Cranfield Water Science Institute, Department of Environmental Science and Technology, Cranfield University, Bedfordshire MK43 0AL, UK
| | - Bruce Jefferson
- Cranfield Water Science Institute, Department of Environmental Science and Technology, Cranfield University, Bedfordshire MK43 0AL, UK.
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126
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Cappel UB, Daeneke T, Bach U. Oxygen-induced doping of spiro-MeOTAD in solid-state dye-sensitized solar cells and its impact on device performance. NANO LETTERS 2012; 12:4925-4931. [PMID: 22913390 DOI: 10.1021/nl302509q] [Citation(s) in RCA: 110] [Impact Index Per Article: 9.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/01/2023]
Abstract
Solid state dye-sensitized solar cells (sDSCs) employing the hole conductor 2,2'7,7'-tetrakis-(N,N-di-p-methoxyphenyl-amine)-9,9'-spirobifluorene (spiro-MeOTAD) require the presence of oxygen during fabrication and storage. In this paper, we determine the concentrations of oxidized spiro-MeOTAD within devices under different operating and storage conditions by UV-vis spectroscopy. Relative concentrations of spiro-MeOTAD(+) were found to be greater than 10% after illumination for standard sDSCs, where no chemical dopant had been used in the solar cell fabrication but oxygen and lithium ions were present. We suggest that oxidized spiro-MeOTAD is created as a byproduct of oxygen reduction at the TiO(2) surface during cell illumination. Furthermore, we studied the effect of light soaking under different conditions and associated changes in spiro-MeOTAD(+) concentration on the solar cell measurements. Our findings give insights to photochemical reactions occurring within sDSCs and provide guidelines for which doping levels should be used in device fabrication in absence of oxygen.
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Affiliation(s)
- Ute B Cappel
- Department of Materials Engineering, Monash University, Victoria 3800, Australia.
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127
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Abstract
AbstractPharmaceutical compounds have been detected in the environment and potentially arise from the discharge of excreted and improperly disposed medication from sewage treatment facilities. In order to minimize environmental exposure of pharmaceutical residues, a potential technique to remove pharmaceuticals from water is the use of an advanced oxidation process (AOP) involving titanium dioxide (TiO2) photocatalysis. To evaluate the extent UV/TiO2 processes have been studied for pharmaceutical degradation, a literature search using the keywords ‘titanium dioxide’, ‘photocatalysis’, ‘advanced oxidation processes’, ‘pharmaceuticals’ and ‘degradation’ were used in the ISI Web of Knowledge TM, Scopus TM and ScienceDirect TM databases up to and including articles published on 23 November 2011. The degradation rates of pharmaceuticals under UV/TiO2 treatment were dependent on type and amount of TiO2 loading, pharmaceutical concentration, the presence of electron acceptors and pH. Complete mineralization under particular experimental conditions were reported for some pharmaceuticals; however, some experiments reported evolution of toxic intermediates during the photocatalytic process. It is concluded that the UV/TiO2 system is potentially a feasible wastewater treatment process, but careful consideration of the treatment time, the loading and the type of TiO2 (doped vs. undoped) used for a particular pharmaceutical is necessary for a successful application (198 words).
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128
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Lira E, Huo P, Hansen JØ, Rieboldt F, Bechstein R, Wei Y, Streber R, Porsgaard S, Li Z, Lægsgaard E, Wendt S, Besenbacher F. Effects of the crystal reduction state on the interaction of oxygen with rutile TiO2(110). Catal Today 2012. [DOI: 10.1016/j.cattod.2011.09.038] [Citation(s) in RCA: 38] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
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129
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Liu H, Yuan J, Jiang Z, Shangguan W, Einaga H, Teraoka Y. Roles of Bi, M and VO4 tetrahedron in photocatalytic properties of novel Bi0.5M0.5VO4 (M=La, Eu, Sm and Y) solid solutions for overall water splitting. J SOLID STATE CHEM 2012. [DOI: 10.1016/j.jssc.2011.11.035] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/14/2022]
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130
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Wilson DP, Sporleder D, White MG. Final state distributions of methyl radical desorption from ketone photooxidation on TiO2(110). Phys Chem Chem Phys 2012; 14:13630-7. [DOI: 10.1039/c2cp42628e] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
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131
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Freeman R, Willner I. Optical molecular sensing with semiconductor quantum dots (QDs). Chem Soc Rev 2012; 41:4067-85. [DOI: 10.1039/c2cs15357b] [Citation(s) in RCA: 393] [Impact Index Per Article: 32.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
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132
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Mali SS, Betty CA, Bhosale PN, Shinde PS, M. R. P, Jadkar SR, Patil PS. Efficient dye-sensitized solar cells based on hierarchical rutile TiO2 microspheres. CrystEngComm 2012. [DOI: 10.1039/c2ce26019k] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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133
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Hansen JO, Huo P, Martinez U, Lira E, Wei YY, Streber R, Laegsgaard E, Hammer B, Wendt S, Besenbacher F. Direct evidence for ethanol dissociation on rutile TiO2(110). PHYSICAL REVIEW LETTERS 2011; 107:136102. [PMID: 22026875 DOI: 10.1103/physrevlett.107.136102] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/01/2011] [Indexed: 05/31/2023]
Abstract
We have studied the interaction of ethanol with reduced TiO(2)(110)-(1 × 1) by high-resolution scanning tunneling microscopy (STM) measurements and density functional theory calculations. The STM data revealed direct evidence for the coexistence of molecularly and dissociatively adsorbed ethanol species on surface Ti sites. In addition, we found evidence for dissociation of ethanol at bridge-bonded O vacancies. The density functional theory calculations support these findings and rationalize the distinct diffusion behaviors of molecularly and dissociatively adsorbed ethanol species, as revealed in time-lapsed STM images.
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Affiliation(s)
- J O Hansen
- Interdisciplinary Nanoscience Center, Department of Physics and Astronomy, Aarhus University, Denmark
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134
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Effect of Fe3+ doping on the performance of TiO2 mechanocoated alumina bead photocatalysts. KOREAN J CHEM ENG 2011. [DOI: 10.1007/s11814-011-0031-7] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
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135
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Lira E, Wendt S, Huo P, Hansen JØ, Streber R, Porsgaard S, Wei Y, Bechstein R, Lægsgaard E, Besenbacher F. The Importance of Bulk Ti3+ Defects in the Oxygen Chemistry on Titania Surfaces. J Am Chem Soc 2011; 133:6529-32. [DOI: 10.1021/ja200884w] [Citation(s) in RCA: 189] [Impact Index Per Article: 14.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Estephania Lira
- Interdisciplinary Nanoscience Center (iNANO) and Department of Physics and Astronomy, Aarhus University, DK 8000 Aarhus C, Denmark
| | - Stefan Wendt
- Interdisciplinary Nanoscience Center (iNANO) and Department of Physics and Astronomy, Aarhus University, DK 8000 Aarhus C, Denmark
| | - Peipei Huo
- Interdisciplinary Nanoscience Center (iNANO) and Department of Physics and Astronomy, Aarhus University, DK 8000 Aarhus C, Denmark
| | - Jonas Ø. Hansen
- Interdisciplinary Nanoscience Center (iNANO) and Department of Physics and Astronomy, Aarhus University, DK 8000 Aarhus C, Denmark
| | - Regine Streber
- Interdisciplinary Nanoscience Center (iNANO) and Department of Physics and Astronomy, Aarhus University, DK 8000 Aarhus C, Denmark
| | - Søren Porsgaard
- Interdisciplinary Nanoscience Center (iNANO) and Department of Physics and Astronomy, Aarhus University, DK 8000 Aarhus C, Denmark
| | - Yinying Wei
- Interdisciplinary Nanoscience Center (iNANO) and Department of Physics and Astronomy, Aarhus University, DK 8000 Aarhus C, Denmark
| | - Ralf Bechstein
- Interdisciplinary Nanoscience Center (iNANO) and Department of Physics and Astronomy, Aarhus University, DK 8000 Aarhus C, Denmark
| | - Erik Lægsgaard
- Interdisciplinary Nanoscience Center (iNANO) and Department of Physics and Astronomy, Aarhus University, DK 8000 Aarhus C, Denmark
| | - Flemming Besenbacher
- Interdisciplinary Nanoscience Center (iNANO) and Department of Physics and Astronomy, Aarhus University, DK 8000 Aarhus C, Denmark
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136
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Yang L, Li G, Hu W, Zhao M, Sun L, Zheng J, Yan T, Li L. Control Over the Crystallinity and Defect Chemistry of YVO4 Nanocrystals for Optimum Photocatalytic Property. Eur J Inorg Chem 2011. [DOI: 10.1002/ejic.201001341] [Citation(s) in RCA: 53] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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137
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Sorescu DC, Lee J, Al-Saidi WA, Jordan KD. CO2 adsorption on TiO2(110) rutile: Insight from dispersion-corrected density functional theory calculations and scanning tunneling microscopy experiments. J Chem Phys 2011; 134:104707. [DOI: 10.1063/1.3561300] [Citation(s) in RCA: 81] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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138
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Schirmer M, Walz MM, Vollnhals F, Lukasczyk T, Sandmann A, Chen C, Steinrück HP, Marbach H. Electron-beam-induced deposition and post-treatment processes to locally generate clean titanium oxide nanostructures on Si(100). NANOTECHNOLOGY 2011; 22:085301. [PMID: 21242619 DOI: 10.1088/0957-4484/22/8/085301] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/30/2023]
Abstract
We have investigated the lithographic generation of TiO(x) nanostructures on Si(100) via electron-beam-induced deposition (EBID) of titanium tetraisopropoxide (TTIP) in ultra-high vacuum (UHV) by scanning electron microscopy (SEM) and local Auger electron spectroscopy (AES). In addition, the fabricated nanostructures were also characterized ex situ via atomic force microscopy (AFM) under ambient conditions. In EBID, a highly focused electron beam is used to locally decompose precursor molecules and thereby to generate a deposit. A drawback of this nanofabrication technique is the unintended deposition of material in the vicinity of the impact position of the primary electron beam due to so-called proximity effects. Herein, we present a post-treatment procedure to deplete the unintended deposits by moderate sputtering after the deposition process. Moreover, we were able to observe the formation of pure titanium oxide nanocrystals (<100 nm) in situ upon heating the sample in a well-defined oxygen atmosphere. While the nanocrystal growth for the as-deposited structures also occurs in the surroundings of the irradiated area due to proximity effects, it is limited to the pre-defined regions, if the sample was sputtered before heating the sample under oxygen atmosphere. The described two-step post-treatment procedure after EBID presents a new pathway for the fabrication of clean localized nanostructures.
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Affiliation(s)
- M Schirmer
- Lehrstuhl für Physikalische Chemie II, Universität Erlangen-Nürnberg, Erlangen, Germany
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139
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(Photo)electrochemical Methods for the Determination of the Band Edge Positions of TiO2-Based Nanomaterials. ACTA ACUST UNITED AC 2011. [DOI: 10.1155/2011/786759] [Citation(s) in RCA: 239] [Impact Index Per Article: 18.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
TiO2-based nanomaterials play currently a major role in the development of novel photochemical systems and devices. One of the key parameters determining the photoactivity of TiO2-based materials is the position of the band edges. Although its knowledge is an important prerequisite for understanding and optimizing the performance of photochemical systems, it has been often rather neglected in recent research, particularly in the field of heterogeneous photocatalysis. This paper provides a concise account of main methods for the determination of the position of the band edges, particularly those suitable for measurements on nanostructured materials. In the first part, a survey of key photophysical and photochemical concepts necessary for understanding the energetics at the semiconductor/solution interface is provided. This is followed by a detailed discussion of several electrochemical, photoelectrochemical, and spectroelectrochemical methods that can be applied for the determination of band edge positions in compact and nanocrystalline thin films, as well as in nanocrystalline powders.
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140
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Visible light photocatalysis by metal halide complexes containing titania as a semiconductor ligand. ADVANCES IN INORGANIC CHEMISTRY 2011. [DOI: 10.1016/b978-0-12-385904-4.00002-0] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
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141
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Mali SS, Betty CA, Bhosale PN, Patil PS. Hydrothermal synthesis of rutile TiO2 with hierarchical microspheres and their characterization. CrystEngComm 2011. [DOI: 10.1039/c1ce05928a] [Citation(s) in RCA: 65] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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142
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Lobo-Lapidus RJ, Gates BC. Probing Surface Sites of TiO2: Reactions with [HRe(CO)5] and [CH3Re(CO)5]. Chemistry 2010; 16:11386-98. [DOI: 10.1002/chem.201000267] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
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143
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Abstract
Titanium dioxide has received great attention both in fundamental and applied photocatalysis due to its low cost, non-toxicity, and stability against photocorrosion [ - ]. Unfortunately it can utilize only the very small UV part (about 3%) of solar light arriving at the earth surface. However, also the visible part (λ > 400 nm) may induce photocatalysis if titania is modified by transition or main group elements. Accordingly, many publications appeared in the last 20 years dealing with the problem of sensitizing titania for visible light photooxidation reactions. This may be achieved by doping, which means substitution of lattice ions, and by surface modification. In many cases authors not clearly differentiate between these two possibilities and so called doped titania quite often is a surface modified material. The latter is easily prepared by heating titania or its precursor compounds like titanium hydroxide in the presence of a modifier at temperatures in the range of 100 – 500 °C. In the following we summarize our work in this field using inorganic and organic sensitizers.
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144
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Du Y, Deskins NA, Zhang Z, Dohnalek Z, Dupuis M, Lyubinetsky I. Formation of O adatom pairs and charge transfer upon O(2) dissociation on reduced TiO(2)(110). Phys Chem Chem Phys 2010; 12:6337-44. [PMID: 20532418 DOI: 10.1039/c000250j] [Citation(s) in RCA: 56] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Scanning tunneling microscopy and density functional theory have been used to investigate the details of O(2) dissociation leading to the formation of oxygen adatom (O(a)) pairs at terminal Ti sites. An intermediate, metastable O(a)-O(a) configuration with two nearest-neighbor O atoms is observed after O(2) dissociation at 300 K. The nearest-neighbor O(a) pairs are destabilized by Coulomb repulsion of charged O(a)'s and separate further along the Ti row into energetically more favorable second-nearest neighbor configuration. The potential energy profile calculated for O(2) dissociation on Ti rows and following O(a)'s separation strongly supports the experimental observations. Furthermore, our results suggest that the itinerant electrons associated with the O vacancies (V(O)) are being utilized in the O(2) dissociation process at the Ti row. Experimentally this is supported by the observation that not all V(O)'s can be healed by O(2) exposure at 300 K, as some V(O)'s becoming less reactive due to supplying certain charge to O(a)'s. Further, theoretical results show that at least two oxygen vacancies per O(2) molecule are required in order for the O(2) dissociation at the Ti row to become viable.
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Affiliation(s)
- Yingge Du
- Environmental Molecular Science Laboratory and Institute for Interfacial Catalysis, Pacific Northwest National Laboratory, Richland, Washington 99352, USA
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145
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146
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147
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Serpone N, Emeline AV, Kuznetsov VN, Ryabchuk VK. Second Generation Visible-Light-Active Photocatalysts: Preparation, Optical Properties, and Consequences of Dopants on the Band Gap Energy of TiO2. NANOSTRUCTURE SCIENCE AND TECHNOLOGY 2010. [DOI: 10.1007/978-0-387-48444-0_3] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/30/2023]
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148
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Thompson SJ, Landau D, Lewis SP. Oxygen pairing on the highly non-stoichiometric (110) surface of TiO2. ACTA ACUST UNITED AC 2010. [DOI: 10.1016/j.phpro.2010.09.053] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
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149
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Photoanodic oxidation of small organic molecules at nanostructured TiO2 anatase and rutile film electrodes. Electrochim Acta 2010. [DOI: 10.1016/j.electacta.2009.08.058] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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150
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Benz L, Haubrich J, Quiller RG, Jensen SC, Friend CM. McMurry Chemistry on TiO2(110): Reductive C═C Coupling of Benzaldehyde Driven by Titanium Interstitials. J Am Chem Soc 2009; 131:15026-31. [DOI: 10.1021/ja905522c] [Citation(s) in RCA: 45] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Lauren Benz
- Department of Chemistry and Chemical Biology and School of Engineering and Applied Sciences, Harvard University, Cambridge, Massachusetts 02138
| | - Jan Haubrich
- Department of Chemistry and Chemical Biology and School of Engineering and Applied Sciences, Harvard University, Cambridge, Massachusetts 02138
| | - Ryan G. Quiller
- Department of Chemistry and Chemical Biology and School of Engineering and Applied Sciences, Harvard University, Cambridge, Massachusetts 02138
| | - Stephen C. Jensen
- Department of Chemistry and Chemical Biology and School of Engineering and Applied Sciences, Harvard University, Cambridge, Massachusetts 02138
| | - Cynthia M. Friend
- Department of Chemistry and Chemical Biology and School of Engineering and Applied Sciences, Harvard University, Cambridge, Massachusetts 02138
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