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Guo HX, Jia HY, Zeng JB, Cong Q, Ren LQ. Characterization and wettability of ZnO film prepared by chemical etching method. Chem Res Chin Univ 2013. [DOI: 10.1007/s40242-013-2181-0] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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102
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Stepien M, Saarinen JJ, Teisala H, Tuominen M, Aromaa M, Haapanen J, Kuusipalo J, Mäkelä JM, Toivakka M. ToF-SIMS analysis of UV-switchable TiO2-nanoparticle-coated paper surface. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2013; 29:3780-3790. [PMID: 23425198 DOI: 10.1021/la304731m] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/01/2023]
Abstract
The chemical composition of a TiO2 nanoparticle coated paper surface was analyzed using time-of-flight secondary ion mass spectrometry (ToF-SIMS) to study the interconnection between wettability and surface chemistry on the nanoscale. In this work, a superhydrophobic TiO2 surface rich in carboxyl-terminated molecules was created by a liquid flame spray process. The TiO2 nanoparticle coated paper surface can be converted by photocatalytic oxidation into a highly hydrophilic one. Interestingly, the hydrophilic surface can be converted back into a superhydrophobic surface by heat treatment. The results showed that both ultraviolet A (UVA) and oven treatment induce changes in the surface chemistry within a few nanometers of the paper surface. These findings are consistent with those from our previously reported X-ray photoelectron spectroscopy (XPS) analysis, but the ToF-SIMS analysis yields more accurate insight into the surface chemistry.
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Affiliation(s)
- Milena Stepien
- Laboratory of Paper Coating and Converting, Center for Functional Materials, Abo Akademi University, Porthansgatan 3, FI-20500 Åbo/Turku, Finland.
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103
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Effect of O2 in O2/Ar Gas Mixture on Morphological and Optical Properties of TiO2 Thin Films Deposited by DC Cylindrical Magnetron Sputtering. JOURNAL OF FUSION ENERGY 2013. [DOI: 10.1007/s10894-013-9598-9] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
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104
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Abstract
Unlike photo-induced super-hydrophilic inorganic thin films, non-photoinduced innate super-hydrophilic TiO2/SiO2 thin films have been successfully prepared in this work. SiO2/TiO2 thin films were prepared by solgel method via adding hydrophilic fumed silica to TiO2 sol and characterized by atomic force microscopy (AFM), scanning electron microscopy (SEM) and contact angle meter. The results show that the super-hydrophilicity of the as-prepared thin films can maintain for one month without light irradiation, and the thin films have excellent antifogging property as well.
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105
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Montero-Ocampo C, Gago A, Abadias G, Gombert B, Alonso-Vante N. In situ photoelectrochemical/photocatalytic study of a dye discoloration in a microreactor system using TiO2 thin films. ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH INTERNATIONAL 2012; 19:3751-3762. [PMID: 23054737 DOI: 10.1007/s11356-012-0771-x] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/13/2011] [Accepted: 01/16/2012] [Indexed: 06/01/2023]
Abstract
INTRODUCTION In this work, we report in situ studies of UV photoelectrocatalytic discoloration of a dye (indigo carmine) by a TiO(2) thin film in a microreactor to demonstrate the driving force of the applied electrode potential and the dye flow rate toward dye discoloration kinetics. METHODS TiO(2) 65-nm-thick thin films were deposited by PVD magnetron sputtering technique on a conducting glass substrate of fluorinated tin oxide. A microreactor to measure the discoloration rate, the electrode potential, and the photocurrent in situ, was developed. The dye solutions, before and after measurements in the microreactor, were analyzed by Raman spectroscopy. RESULTS The annealed TiO(2) thin films had anatase structure with preferential orientation (101). The discoloration rate of the dye increased with the applied potential to TiO(2) electrode. Further, acceleration of the photocatalytic reaction was achieved by utilizing dye flow recirculation to the microreactor. In both cases the photoelectrochemical/photocatalytic discoloration kinetics of the dye follows the Langmuir-Hinshelwood model, with first-order kinetics. CONCLUSIONS The feasibility of dye discoloration on TiO(2) thin film electrodes, prepared by magnetron sputtering using a flow microreactor system, has been clearly demonstrated. The discoloration rate is enhanced by applying a positive potential (E (AP)) and/or increasing the flow rate. The fastest discoloration and shortest irradiation time (50 min) produced 80% discoloration with an external anodic potential of 0.931 V and a flow rate of 12.2 mL min(-1).
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Affiliation(s)
- C Montero-Ocampo
- Laboratoire d'Electrocatalyse, UMR-CNRS 7285, Université de Poitiers, 4 rue Michel Brunet, B27-BP633, 86022, Poitiers, France
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106
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Katsumata KI, Ohno Y, Tomita K, Taniguchi T, Matsushita N, Okada K. Synthesis of amphiphilic brookite nanoparticles with high photocatalytic performance for wide range of application. ACS APPLIED MATERIALS & INTERFACES 2012; 4:4846-52. [PMID: 22860713 DOI: 10.1021/am301183t] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/04/2023]
Abstract
Brookite TiO(2) nanoparticles with amphiphilic properties were successfully synthesized with a water-soluble titanium glycolate complex precursor using an oleate-modified hydrothermal growth process. The ~20-40 nm TiO(2) nanoparticles were highly dispersible in both water and cyclohexane. The activity of the brookite nanoparticles for the degradation of acetaldehyde under UV irradiation was higher than that of Degussa P-25 TiO(2) powder. A spin-coated brookite film prepared on a polyimide substrate exhibited photoinduced hydrophilicity. Thus, these synthesized brookite nanoparticles could be applied as a photocatalytic coating solution.
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Affiliation(s)
- Ken-ichi Katsumata
- Materials and Structures Laboratory, Tokyo Institute of Technology, 4259 Nagatsuta, Midori, Yokohama, Kanagawa 226-8503, Japan.
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107
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108
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Fu N, Tang X, Li D. Application of in situ measurement of photo-induced variations in electron work function for in-depth understanding of the photocatalytic activity of TiO2 nanotubes. NANOTECHNOLOGY 2012; 23:275704. [PMID: 22705558 DOI: 10.1088/0957-4484/23/27/275704] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/01/2023]
Abstract
The electron work function (EWF) is the minimum energy required to move an electron at the Fermi level from inside a conducting material to its surface with zero kinetic energy. This fundamental parameter is directly related to many chemical, physical, and mechanical properties of materials. In this work, variations in EWF of TiO(2) nanotube arrays under light illumination were monitored in situ using a Kelvin probe in order to study the photon-induced electron excitation in the TiO(2) nanotubular arrays upon illumination. It was shown that the EWF could be used to investigate the electron-hole separation and recombination, helping us to better understand the photo-activity of the photocatalytic material. This study has demonstrated that EWF provides an effective parameter for understanding of semiconductors' photo-activities with different views that may not be achieved using traditional techniques, such as diffuse reflection spectroscopy and photoelectrochemical measurement.
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Affiliation(s)
- Ning Fu
- Department of Chemical and Materials Engineering, University of Alberta, Edmonton, AB T6G 2V4, Canada
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109
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Tsou HK, Hsieh PY, Chi MH, Chung CJ, He JL. Improved osteoblast compatibility of medical-grade polyetheretherketone using arc ionplated rutile/anatase titanium dioxide films for spinal implants. J Biomed Mater Res A 2012; 100:2787-92. [DOI: 10.1002/jbm.a.34215] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2011] [Revised: 03/30/2012] [Accepted: 04/05/2012] [Indexed: 11/11/2022]
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110
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Dunnill CW, Kafizas A, Parkin IP. CVD Production of Doped Titanium Dioxide Thin Films. ACTA ACUST UNITED AC 2012. [DOI: 10.1002/cvde.201200048] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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111
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Ion engineering techniques for the preparation of the highly effective TiO2 photocatalysts operating under visible light irradiation. RESEARCH ON CHEMICAL INTERMEDIATES 2012. [DOI: 10.1007/s11164-011-0465-x] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
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112
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Yang M, Di Z, Lee JK. Facile control of surface wettability in TiO2/poly(methyl methacrylate) composite films. J Colloid Interface Sci 2012; 368:603-7. [DOI: 10.1016/j.jcis.2011.11.037] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2011] [Revised: 11/14/2011] [Accepted: 11/17/2011] [Indexed: 10/14/2022]
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113
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Cardiel AC, Benson MC, Bishop LM, Louis KM, Yeager JC, Tan Y, Hamers RJ. Chemically directed assembly of photoactive metal oxide nanoparticle heterojunctions via the copper-catalyzed azide-alkyne cycloaddition "click" reaction. ACS NANO 2012; 6:310-318. [PMID: 22196212 DOI: 10.1021/nn203585r] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/31/2023]
Abstract
Metal oxides play a key role in many emerging applications in renewable energy, such as dye-sensitized solar cells and photocatalysts. Because the separation of charge can often be facilitated at junctions between different materials, there is great interest in the formation of heterojunctions between metal oxides. Here, we demonstrate use of the copper-catalyzed azide-alkyne cycloaddition reaction, widely referred to as "click" chemistry, to chemically assemble photoactive heterojunctions between metal oxide nanoparticles, using WO(3) and TiO(2) as a model system. X-ray photoelectron spectroscopy and Fourier-transform infrared spectroscopy verify the nature and selectivity of the chemical linkages, while scanning electron microscopy reveals that the TiO(2) nanoparticles form a high-density, conformal coating on the larger WO(3) nanoparticles. Time-resolved surface photoresponse measurements show that the resulting dyadic structures support photoactivated charge transfer, while measurements of the photocatalytic degradation of methylene blue show that chemical grafting of TiO(2) nanoparticles to WO(3) increases the photocatalytic activity compared with the bare WO(3) film.
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Affiliation(s)
- Allison C Cardiel
- Department of Chemistry, University of Wisconsin-Madison, 1101 University Avenue, Madison, Wisconsin 53706, USA
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114
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Ganesh VA, Nair AS, Raut HK, Walsh TM, Ramakrishna S. Photocatalytic superhydrophilic TiO2 coating on glass by electrospinning. RSC Adv 2012. [DOI: 10.1039/c2ra00921h] [Citation(s) in RCA: 74] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
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115
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Macias-Montero M, Borras A, Saghi Z, Romero-Gomez P, Sanchez-Valencia JR, Gonzalez JC, Barranco A, Midgley P, Cotrino J, Gonzalez-Elipe AR. Superhydrophobic supported Ag-NPs@ZnO-nanorods with photoactivity in the visible range. ACTA ACUST UNITED AC 2012. [DOI: 10.1039/c1jm13512k] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
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116
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Sun P, Zhu M, Ma R, Wang K, Wei J, Wu D, Sasaki T, Zhu H. Graphene oxide/titania hybrid films with dual-UV-responsive surfaces of tunable wettability. RSC Adv 2012. [DOI: 10.1039/c2ra21699j] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
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117
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Yang BS, Park S, Oh S, Kim YJ, Jeong JK, Hwang CS, Kim HJ. Improvement of the photo-bias stability of the Zn–Sn–O field effect transistors by an ozone treatment. ACTA ACUST UNITED AC 2012. [DOI: 10.1039/c2jm30242j] [Citation(s) in RCA: 68] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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118
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Zigah D, Rodríguez-López J, Bard AJ. Quantification of photoelectrogenerated hydroxyl radical on TiO2 by surface interrogation scanning electrochemical microscopy. Phys Chem Chem Phys 2012; 14:12764-72. [DOI: 10.1039/c2cp40907k] [Citation(s) in RCA: 72] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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119
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Horprathum M, Eiamchai P, Chindaudom P, Pokaipisit A, Limsuwan P. Oxygen Partial Pressure Dependence of the Properties of TiO2 Thin Films Deposited by DC Reactive Magnetron Sputtering. ACTA ACUST UNITED AC 2012. [DOI: 10.1016/j.proeng.2012.01.1326] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/28/2022]
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120
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Ahmed AY, Oekermann T, Lindner P, Bahnemann D. Comparison of the photoelectrochemical oxidation of methanol on rutile TiO2 (001) and (100) single crystal faces studied by intensity modulated photocurrent spectroscopy. Phys Chem Chem Phys 2012; 14:2774-83. [DOI: 10.1039/c2cp23416e] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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121
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Núñez-Rojas E, Domínguez H. Computational studies on the behavior of Sodium Dodecyl Sulfate (SDS) at TiO2(rutile)/water interfaces. J Colloid Interface Sci 2011; 364:417-27. [DOI: 10.1016/j.jcis.2011.08.069] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2011] [Revised: 08/25/2011] [Accepted: 08/26/2011] [Indexed: 11/26/2022]
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122
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Du Y, Petrik NG, Deskins NA, Wang Z, Henderson MA, Kimmel GA, Lyubinetsky I. Hydrogen reactivity on highly-hydroxylated TiO2(110) surfaces prepared via carboxylic acid adsorption and photolysis. Phys Chem Chem Phys 2011; 14:3066-74. [PMID: 22108618 DOI: 10.1039/c1cp22515d] [Citation(s) in RCA: 56] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Combined scanning tunneling microscopy, temperature programmed desorption, photo stimulated desorption, and density functional theory studies have probed the formation and reactivity of highly-hydroxylated rutile TiO(2)(110) surfaces, which were prepared via a novel, photochemical route using trimethyl acetic acid (TMAA) dissociative adsorption and subsequent photolysis at 300 K. Deprotonation of TMAA molecules upon adsorption produces both surface bridging hydroxyls (OH(b)) and bidentate trimethyl acetate (TMA) species with a saturation coverage of nearly 0.5 monolayers (ML). Ultra-violet light irradiation selectively removes TMA species, producing a highly-hydroxylated surface with up to ~0.5 ML OH(b) coverage. At high coverages, the OH(b) species typically occupy second-nearest neighbor sites along the bridging oxygen row locally forming linear (2 × 1) structures of different lengths, although the surface is less ordered on a long scale. The annealing of the highly-hydroxylated surface leads to hydroxyl recombination and H(2)O desorption with ~100% yield, thus ruling out the diffusion of H into the bulk that has been suggested in the literature. In agreement with experimental data, theoretical results show that the recombinative H(2)O desorption is preferred over both H bulk diffusion and H(2) desorption processes.
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Affiliation(s)
- Y Du
- Environmental Molecular Science Laboratory and Institute for Integrated Catalysis, Pacific Northwest National Laboratory, Richland, WA 99352, USA
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123
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Evtushenko YM, Romashkin SV, Davydov VV. Synthesis and properties of TiO2-based nanomaterials. THEORETICAL FOUNDATIONS OF CHEMICAL ENGINEERING 2011. [DOI: 10.1134/s0040579511050071] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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124
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Kim BS, Shin S, Shin SJ, Kim KM, Cho HH. Control of superhydrophilicity/superhydrophobicity using silicon nanowires via electroless etching method and fluorine carbon coatings. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2011; 27:10148-10156. [PMID: 21728376 DOI: 10.1021/la200940j] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/31/2023]
Abstract
Surface roughness is promotive of increasing their hydrophilicity or hydrophobicity to the extreme according to the intrinsic wettability determined by the surface free energy characteristics of a base substrate. Top-down etched silicon nanowires are used to create superhydrophilic surfaces based on the hemiwicking phenomenon. Using fluorine carbon coatings, surfaces are converted from superhydrophilic to superhydrophobic to maintain the Cassie-Baxter state stability by reducing the surface free energy to a quarter compared with intrinsic silicon. We present the robust criteria by controlling the height of the nanoscale structures as a design parameter and design guidelines for superhydrophilic and superhydrophobic conditions. The morphology of the silicon nanowires is used to demonstrate their critical height exceeds several hundred nanometers for superhydrophilicity, and surpasses a micrometer for superhydrophobicity. Especially, SiNWs fabricated with a height of more than a micrometer provide an effective means of maintaining superhydrophilic (<10°) long-term stability.
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Affiliation(s)
- Beom Seok Kim
- Department of Mechanical Engineering, Yonsei University, 262, Seongsanno, Seodaemun-gu, Seoul 120-749, Korea
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125
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Liu YJ, Shi J, Zhang F, Liang H, Xu J, Lakhtakia A, Fonash SJ, Huang TJ. High-speed optical humidity sensors based on chiral sculptured thin films. SENSORS AND ACTUATORS. B, CHEMICAL 2011; 156:593-598. [PMID: 30739999 PMCID: PMC6365146 DOI: 10.1016/j.snb.2011.02.003] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/21/2023]
Abstract
A high-speed humidity sensor based on a nanostructured chiral sculptured thin film (CSTF) was fabricated and tested. The sensing principle is based on the shift of the central wavelength of the circular Bragg regime of the CSTF caused by adsorption and desorption of water vapor in the void regions of the CSTF. Spectral changes due to varying relative-humidity (RH) levels in the ambient environment were measured by a spectrometer. The CSTF sensor exhibited excellent reversibility and reproducibility from 40% to 100% RH. Moreover, the adsorption time of the sensor was measured to be as low as ∼140 ms, making it promising for many high-speed humidity-sensing applications.
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Affiliation(s)
| | | | | | | | | | | | | | - Tony Jun Huang
- Corresponding author. Tel.: +1 814 863 4209; fax: +1 814 865 9974., (T.J. Huang)
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126
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Katsumata KI, Ohno Y, Tomita K, Sakai M, Nakajima A, Kakihana M, Fujishima A, Matsushita N, Okada K. Preparation of TiO2 Thin Films Using Water-soluble Titanium Complexes and Their Photoinduced Properties. Photochem Photobiol 2011; 87:988-94. [DOI: 10.1111/j.1751-1097.2011.00944.x] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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127
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Okudaira K, Kato T, Isobe T, Matsushita S, Kogure T, Nakajima A. Wettability conversion and surface friction force variation of polycrystalline rutile ceramics under UV illumination. J Photochem Photobiol A Chem 2011. [DOI: 10.1016/j.jphotochem.2011.05.002] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
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128
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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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129
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Enhancing photoinduced hydrophilicity of micro arc oxidized TiO2 nanostructured porous layers by V-doping. Colloids Surf A Physicochem Eng Asp 2011. [DOI: 10.1016/j.colsurfa.2010.10.025] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
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130
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Gu F, Gai L, Shao W, Li C, Schmidt-Mende L. Heteroepitaxial growth of ZnO branches selectively on TiO2 nanorod tips with improved light harvesting performance. Chem Commun (Camb) 2011; 47:8400-2. [DOI: 10.1039/c1cc12309b] [Citation(s) in RCA: 27] [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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131
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Singh J, Whitten JE. Directed adhesion and patterning by ultraviolet irradiation of TiO2(110). LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2010; 26:17795-17797. [PMID: 21062100 DOI: 10.1021/la103174f] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/30/2023]
Abstract
Forces of adhesion between a hydroxylated silicon oxide tip and a TiO(2)(110) surface, before and after irradiation of the surface with 254 nm light, were measured using atomic force microscopy. The work of adhesion before and after irradiation was 32 and 166 mJ/m(2), respectively, but a difference was observed only if ultraviolet light exposure was used in the presence of oxygen. The change in adhesion correlated strongly with decreasing water contact angle, which changed from ca. 70 to 0° because of irradiation. The contrast in adhesion between irradiated and nonirradiated regions of the surface makes possible a simple method of patterning molecules with micrometer, and potentially nanoscale, resolution. As an example, fluorescein was selectively adsorbed onto hydrophilic regions of the surface by spin coating an ethanolic fluorescein solution onto TiO(2)(110) that had been irradiated through a photomask.
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Affiliation(s)
- Jagdeep Singh
- Department of Chemistry and Center for High-Rate Nanomanufacturing, The University of Massachusetts, Lowell, Lowell, Massachusetts 01854, United States
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132
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Monteleone FV, Caputo G, Canale C, Cozzoli PD, Cingolani R, Fragouli D, Athanassiou A. Light-controlled directional liquid drop movement on TiO2 nanorods-based nanocomposite photopatterns. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2010; 26:18557-18563. [PMID: 21028854 DOI: 10.1021/la1026398] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/28/2023]
Abstract
Patterned polymeric coatings enriched with colloidal TiO(2) nanorods and prepared by photopolymerization are found to exhibit a remarkable increase in their water wettability when irradiated with UV laser light. The effect can be completely reversed using successive storage in vacuum and dark ambient environment. By exploiting the enhancement of the nanocomposites hydrophilicity upon UV irradiation, we prepare wettability gradients along the surfaces by irradiating adjacent surface areas with increasing time. The gradients are carefully designed to achieve directional movement of water drops along them, taking into account the hysteresis effect that opposes the movement as well as the change in the shape of the drop during its motion. The accomplishment of surface paths for liquid flow, along which the hydrophilicity gradually increases, opens the way to a vast number of potential applications in microfluidics.
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133
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Borras A, González-Elipe AR. Wetting properties of polycrystalline TiO2 surfaces: a scaling approach to the roughness factors. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2010; 26:15875-15882. [PMID: 20873762 DOI: 10.1021/la101975e] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/29/2023]
Abstract
This work presents a thorough study on the wettability of polycrystalline anatase TiO(2) thin films prepared at 250 °C in a microwave plasma enhanced chemical vapor deposition (MW-PECVD) reactor with Ar/O(2) plasmas. Anatase polycrystalline thin films with different microstructures, textures, and surface roughness were obtained as a function of their thickness. The water contact angle of the samples was analyzed within the assumptions of the Wenzel, Cassie, and Miwa models to ascertain the effect of roughness and other surface heterogeneities on their characteristic parameters. The roughness factors defined in the different models were calculated from the atomic force microscopy (AFM) images of the films for two different observation scales within the premises of the dynamic scaling theories. The obtained results indicate that the wetting angle of an equivalent flat anatase surface with a value of 82° can only be properly estimated for observation scales of 5 × 5 μm(2) and using the Miwa model. The analysis of the UV induced hydrophilization of the surface state of the anatase films and the posterior recovery of the partially hydrophobic character of these surfaces in the absence of UV photons suggest a clear dependence of the light induced wettability on their texture and size of crystalline domains.
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Affiliation(s)
- Ana Borras
- Instituto de Ciencia de Materiales de Sevilla (CSIC-Univ. Sevilla), Avd. Américo Vespucio 49, 41092 Sevilla, Spain.
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134
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Zuo J, Torres E. Comparison of adsorption of mercaptopropyltrimethoxysilane on amphiphilic TiO2 and hydroxylated SiO2. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2010; 26:15161-8. [PMID: 20839828 DOI: 10.1021/la102221v] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/25/2023]
Abstract
Alkylsilane 3-mercaptopropyltrimethoxysilane (3MPT) monolayers with a functional end group -SH were used to immobilize Ag colloidal nanoparticles on photoinduced amphiphilic TiO(2) and hydroxylated SiO(2) surfaces. The differences in the adsorption of 3MPT and the immobilization of Ag colloids on both surfaces were studied. Under identical experimental conditions, 3MPT islands were formed on UV-exposed TiO(2) surfaces compared to continuous and flat monolayers formed on SiO(2). The significant structural differences found for monolayers of 3MPT on TiO(2) could be explained in terms of the different densities of hydroxyl groups and the microstructure of hydrophilic domains induced by UV irradiation. The surface properties were characterized using contact angle measurements and XPS. XPS showed an increase in the hydroxyl group's density and a decrease in the number of adsorbed hydrocarbon films on the TiO(2) surface as a function of the UV irradiation time. The density of the adsorbed 3MPT on TiO(2) surfaces as a function of the UV irradiation time was quantitatively related to the cosine of the water contact angles. Such a 3MPT distribution influenced the subsequent adsorption of Ag colloids and resulted in more isolated nanoparticles on the modified TiO(2) with a narrower size distribution.
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Affiliation(s)
- J Zuo
- Department of Interface Chemistry and Surface Engineering, Max-Planck-Institut für Eisenforschung GmbH, Max-Planck-Strasse 1, D-40237 Düsseldorf, Germany
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135
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Renckens T, Almeida A, Damen M, Kreutzer M, Mul G. Product desorption limitations in selective photocatalytic oxidation. Catal Today 2010. [DOI: 10.1016/j.cattod.2009.12.002] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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136
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Qiu X, Wang Z, Zhu J, Oiler J, Tang R, Yu C, Yu H. The effects of relative humidity and reducing gases on the temperature coefficient of resonant frequency of ZnO-based film bulk acoustic wave resonator. IEEE TRANSACTIONS ON ULTRASONICS, FERROELECTRICS, AND FREQUENCY CONTROL 2010; 57:1902-1905. [PMID: 20875979 DOI: 10.1109/tuffc.2010.1637] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/29/2023]
Abstract
This study describes the influence of relative humidity (RH) and reducing gases on the temperature coefficient of resonant frequency (TCF) of ZnO-based film bulk acoustic wave resonator (FBAR). Upon exposure to moisture or reducing gases, the TCF of FBAR decreased. Water molecules can replace adsorbed oxygen on the ZnO surface. This process was less effective at high temperature, resulting in a lower TCF in high RH. Reducing gases, such as acetone, can reduce the density of ZnO through reaction with the adsorbed oxygen, leading to a lower TCF.
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137
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Nakata K, Kimura H, Sakai M, Ochiai T, Sakai H, Murakami T, Abe M, Fujishima A. UV/thermally driven rewritable wettability patterns on TiO2-PDMS composite films. ACS APPLIED MATERIALS & INTERFACES 2010; 2:2485-2488. [PMID: 20712336 DOI: 10.1021/am1005207] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/29/2023]
Abstract
Composite films of TiO2 and polydimethylsiloxane (PDMS) are prepared by a sol-gel method, cured with UV irradiation, and then treated in hot water to crystallize the TiO2 in the film. The presence of anatase TiO2 contributes to the photoinduced superhydrophilicity of the film under UV irradiation. Contact angle studies reveal that the TiO2-PDMS composite film recovers its original hydrophobic state. Hydrophobic-superhydrophilic patterns are successfully formed on the films. The wettability patterns can be erased by UV irradiation and thermal treatment. New wettability patterns can be reconstructed, demonstrating that the film exhibits rewritable wettability without the need for organic chemicals.
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Affiliation(s)
- Kazuya Nakata
- Photocatalyst Group, Kanagawa Academy of Science and Technology, KSP Building West 614, 3-2-1 Sakado, Takatsu-ku, Kawasaki, Kanagawa 213-0012, Japan
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138
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Yaghoubi H, Taghavinia N, Alamdari EK, Volinsky AA. Nanomechanical properties of TiO2 granular thin films. ACS APPLIED MATERIALS & INTERFACES 2010; 2:2629-2636. [PMID: 20715790 DOI: 10.1021/am100455q] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/29/2023]
Abstract
Post-deposition annealing effects on nanomechanical properties of granular TiO2 films on soda-lime glass substrates were studied. In particular, the effects of Na diffusion on the films' mechanical properties were examined. TiO2 photocatalyst films, 330 nm thick, were prepared by dip-coating using a TiO2 sol, and were annealed between 100 °C and 500 °C. Film's morphology, physical and nanomechanical properties were characterized by atomic force microscopy, X-ray photoelectron spectroscopy, X-ray diffraction, differential thermo-gravimetric analysis, and nanoindentation. Contrary to expectations, the maximum film hardness was achieved for 300°C annealing, with a value of 0.69±0.05 GPa. Higher annealing temperatures resulted in inferior mechanical properties. No pile-up or sink-in effects were observed with minimal creep for the 300 °C annealed sample. Considerable decrease in the amount of chemisorbed water was found with increasing annealing temperature, causing gel films densification, explaining the increasing trend of hardness with annealing temperature between 100 °C and 300 °C. DTA/TGA results also confirmed the weight loss and the endothermic reaction due to desorption of chemisorbed water. Decrease in hardness above 300 °C annealing is attributed to thermal diffusion of Na ions from the glass substrate, confirmed by nanoindentation tests on TiO2 films deposited on fused quartz, which did not exhibit hardness decrease after 300 °C annealing.
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Affiliation(s)
- Houman Yaghoubi
- New Materials Department, Materials and Energy Research Center (MERC), P.O. Box 14155-4777, Tehran, Iran
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139
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Xtao-Li C, Da-Sen R, Song-Tao W, Jie S, Xi-Liang Y, Zhuang-Jian Z. Two Photoelectrochemical Processes for TiO2 Electrode under UV Illumination. CHINESE J CHEM 2010. [DOI: 10.1002/cjoc.20030210805] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
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140
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Yan S, Wan L, Li Z, Zhou Y, Zou Z. Synthesis of a mesoporous single crystal Ga2O3 nanoplate with improved photoluminescence and high sensitivity in detecting CO. Chem Commun (Camb) 2010; 46:6388-90. [PMID: 20714548 DOI: 10.1039/c0cc01579b] [Citation(s) in RCA: 48] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
A new approach is proposed to synthesize a mesoporous single crystal Ga(2)O(3) nanoplate by heating a single crystal nanoplate of GaOOH, which involves an ion exchange between KGaO(2) and CH(3)COOH at room temperature for the formation of GaOOH and pseudomorphic and topotactic phase transformation from GaOOH to Ga(2)O(3).
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Affiliation(s)
- Shicheng Yan
- Ecomaterials and Renewable Energy Research Center (ERERC), National Laboratory of Solid State Microstructures, Nanjing University, Nanjing 210093, P.R. China
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141
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Bayati M, Molaei R, Kajbafvala A, Zanganeh S, Zargar H, Janghorban K. Investigation on hydrophilicity of micro-arc oxidized TiO2 nano/micro-porous layers. Electrochim Acta 2010. [DOI: 10.1016/j.electacta.2010.05.021] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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142
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Shibata T, Irie H, Tryk DA, Hashimoto K. Surface residual stress dependence on photoinduced highly hydrophilic conversion and back-reaction in the dark of rutile single crystals. Phys Chem Chem Phys 2010; 12:7911-6. [PMID: 20505886 DOI: 10.1039/b927332h] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
The wettability changes of TiO(2) surface, photo-induced hydrophilic conversion and back-reaction in the dark, were evaluated using rutile (100) and (001) single crystals with diamond polishing (DP) and chemical mechanical polishing (CMP) treatments. Dynamic hardness measurements indicated that the DP surface had a residual compressive stress; however, the CMP surface did not. The rate of hydrophilic conversion was greatly suppressed (approximately one fourteenth) on the DP surface compared to the CMP surface, showing that the photoinduced hydrophilicity was greatly suppressed on the surface with compressive stress although the number of photogenerated carriers at the DP surface was estimated to decrease to only ca. half that at the CMP surface. In addition, when a heat treatment relaxed the compressive stress, the hydrophilicity was greatly increased. The back-reaction in the dark, i.e., the degradation of the photo-produced hydrophilic state, was ca. two times faster on the DP surface with compressive stress. The results strongly suggest that the pressure effect caused by the compressive stress could be the main reason for the degradation of the hydrophilicity and acceleration of the back reaction.
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Affiliation(s)
- Tatsuo Shibata
- Department of Applied Chemistry, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-8656, Japan
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143
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Katsumata KI, Okazaki S, Cordonier CEJ, Shichi T, Sasaki T, Fujishima A. Preparation and characterization of self-cleaning glass for vehicle with niobia nanosheets. ACS APPLIED MATERIALS & INTERFACES 2010; 2:1236-1241. [PMID: 20359208 DOI: 10.1021/am100091f] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/29/2023]
Abstract
Self-cleaning glasses were prepared by coating niobia nanosheets and investigated on the performance. The coated glass heated at >450 degrees C had very low turbidity, high hardness, and excellent adhesion properties. Niobia nanosheets ([Nb(3)O(8)](-)) reacted with sodium ions (Na(+)) diffused from the glass into the films to form a crystalline phase of NaNb(3)O(8) and this phase was converted to NaNbO(3) at >450 degrees C. The films exhibited photoinduced hydrophilicity under UV irradiation but low photocatalytic oxidation activity. Excellent self-cleaning ability of the niobia nanosheet coated glass was confirmed by the Taber abrasion test, which is thought to be a candidate as self-cleaning glasses for vehicles.
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Affiliation(s)
- Ken-ichi Katsumata
- Materials and Structures Laboratory, Tokyo Institute of Technology, Midori-ku, Yokohama, Kanagawa 226-8503 Japan.
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144
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Lee K, Kim D, Roy P, Paramasivam I, Birajdar BI, Spiecker E, Schmuki P. Anodic formation of thick anatase TiO2 mesosponge layers for high-efficiency photocatalysis. J Am Chem Soc 2010; 132:1478-9. [PMID: 20078123 DOI: 10.1021/ja910045x] [Citation(s) in RCA: 154] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
We report a process for the fabrication of an anatase TiO(2) mesosponge (TMS) layer by an optimized Ti anodization process in a hot glycerol electrolyte followed by a suitable etching process. Such layers can easily be grown to >10 microm thickness and have regular channels and structural features in the 5-20 nm range. The layers show high photocatalytic activity and are mechanically very robust. The layers therefore open new pathways to the wide field of TiO(2)(anatase) applications.
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Affiliation(s)
- Kiyoung Lee
- Department of Materials Science, WW4-LKO, University of Erlangen-Nuremberg, Martensstrasse 7, D-91058 Erlangen, Germany
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145
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Zare-Hossein-abadi D, Ershad-Langroudi A, Rahimi A, Afsar S. Photo-Generated Activities of Nanocrystalline TiO2 Thin Films. J Inorg Organomet Polym Mater 2010. [DOI: 10.1007/s10904-010-9334-0] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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146
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Miyauchi M, Liu Z, Zhao ZG, Anandan S, Tokudome H. Visible-light-driven superhydrophilicity by interfacial charge transfer between metal ions and metal oxide nanostructures. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2010; 26:796-801. [PMID: 19681627 DOI: 10.1021/la902177x] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/28/2023]
Abstract
Single-crystalline rutile nanorods were synthesized by a facile acid treatment on titanate nanotubes. These rutile nanorods could be highly dispersed in water to form a stable colloidal solution. Cu(2+) ions were grafted onto these rutile nanorods, and the Cu(2+)-grafted nanorods could absorb visible light by the interfacial charge transfer between the valence band of rutile TiO(2) and surface-modified Cu(2+) ions. Transparent thin films of Cu(2+)-grafted nanorods were coated on substrates by a facile spin-coating method. These films exhibited superhydrophilic conversion under visible light irradiation.
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Affiliation(s)
- Masahiro Miyauchi
- National Institute of Advanced Industrial Science and Technology, Tsukuba Central 5, 1-1-1 Higashi, Tsukuba, Ibaraki 305-8565, Japan.
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147
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Tricoli A, Righettoni M, Pratsinis SE. Anti-fogging nanofibrous SiO(2) and nanostructured SiO(2)-TiO(2) films made by rapid flame deposition and in situ annealing. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2009; 25:12578-12584. [PMID: 19621912 DOI: 10.1021/la901759p] [Citation(s) in RCA: 46] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/28/2023]
Abstract
Transparent, pure SiO(2), TiO(2), and mixed silica-titania films were (stochastically) deposited directly onto glass substrates by flame spray pyrolysis of organometallic solutions (hexamethyldisiloxane or tetraethyl orthosilicate and/or titanium tetra isopropoxide in xylene) and stabilized by in situ flame annealing. Silicon dioxide films consisted of a network of interwoven nanofibers or nanowires several hundred nm long and 10-15 nm thick, as determined by microscopy. These nanowire or nanofibrous films were formed by chemical vapor deposition (surface growth) on bare glass substrates during scalable combustion of precursor solutions at ambient conditions, for the first time to our knowledge, as determined by thermophoretic sampling of the flame aerosol and microscopy. In contrast, titanium dioxide films consisted of nanoparticles 3-5 nm in diameter that were formed in the flame and deposited onto the glass substrate, resulting in highly porous, lace-like nanostructures. Mixed SiO(2)-TiO(2) films (40 mol % SiO(2)) had similar morphology to pure TiO(2) films. Under normal solar radiation, all such films having a minimal thickness of about 300 nm completely prevented fogging of the glass substrates. These anti-fogging properties were attributed to inhibition of water droplet formation by such super-hydrophilic coatings as determined by wetting angle measurements. Deactivated (without UV radiation) pure TiO(2) coatings lost their super-hydrophilicity and anti-fogging properties even though their wetting angle was reduced by their nanowicking. In contrast, SiO(2)-TiO(2) coatings exhibited the best anti-fogging performance at all conditions taking advantage of the high surface coverage by TiO(2) nanoparticles and the super-hydrophilic properties of SiO(2) on their surface.
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Affiliation(s)
- Antonio Tricoli
- Particle Technology Laboratory, Institute of Process Engineering, Department of Mechanical and Process Engineering, ETH Zurich, CH-8092 Zurich, Switzerland
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148
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Ohtsu N, Masahashi N, Mizukoshi Y, Wagatsuma K. Hydrocarbon decomposition on a hydrophilic TiO2 surface by UV irradiation: spectral and quantitative analysis using in-situ XPS technique. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2009; 25:11586-11591. [PMID: 19788218 DOI: 10.1021/la901505m] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/28/2023]
Abstract
This paper presents valuable evidence in support of the removal of a contaminant hydrocarbon layer adsorbed on photocatalytic TiO2 film by the latter's photo-oxidization. UV light was radiated on an anodic TiO2 film in an atmosphere-controlled chamber, and the film was then transferred to an ultrahigh-vacuum chamber for X-ray photoelectron spectroscopic (XPS) analysis; during the transfer, care was taken to ensure that the film was not exposed to air. This "in situ" setting eliminates the influence of carbon and water adsorptions during the transfer, thus enabling the accurate analysis of the UV-induced surface reaction. The spectral and quantitative results clearly revealed that the adsorbed hydrocarbon was removed from the photocatalytic TiO2 film when the film was irradiated in an oxygen atmosphere. Such removal occurs only in the case of TiO2 films that exhibit superhydrophilicity. This indicates that the removal of hydrocarbon is dependent on the UV-induced hydrophilicity on the film. In situ XPS measurement also presented evidence for UV-induced hydroxide group adsorption, where the adsorption was observed on both the surfaces showing superhydrophilicity and devoid of it.
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Affiliation(s)
- Naofumi Ohtsu
- Instrumental Analysis Center, Kitami Institute of Technology, Kitami, Hokkaido 090-8507, Japan.
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149
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Liu P, Cai W, Fang M, Li Z, Zeng H, Hu J, Luo X, Jing W. Room temperature synthesized rutile TiO(2) nanoparticles induced by laser ablation in liquid and their photocatalytic activity. NANOTECHNOLOGY 2009; 20:285707. [PMID: 19550020 DOI: 10.1088/0957-4484/20/28/285707] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/20/2023]
Abstract
TiO(2) nanoparticles were prepared by one-step pulsed laser ablation of a titanium target immersed in a poly-(vinylpyrrolidone) solution at room temperature. The products were systematically characterized by x-ray diffraction (XRD), transmission electron microscopy (TEM), Raman spectroscopy and x-ray photoelectron spectroscopy (XPS). The results indicated that the rutile TiO(2) nanocrystalline particles were one-step synthesized at room temperature and the mean size in diameter is about 50 nm with a narrow size distribution. A probable formation process was proposed on the basis of the microstructure and the instantaneous plasma plume induced by the laser. Photocatalytic activity was monitored by degradation of a methylene blue solution. The as-prepared rutile TiO(2) nanoparticles demonstrate a good photocatalytic performance. This work shows that pulsed laser ablation in liquid media is a good method to synthesize some nanosized materials which are difficult to produce by other conventional methods.
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Affiliation(s)
- Peisheng Liu
- Key Laboratory of Materials Physics, Anhui Key Laboratory of Nanomaterials and Nanotechnology, Institute of Solid State Physics, Chinese Academy of Sciences, Hefei, PR China.
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150
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Han Y, Wu G, Wang M, Chen H. The growth of a c-axis highly oriented sandwiched TiO2 film with superhydrophilic properties without UV irradiation on SnO:F substrate. NANOTECHNOLOGY 2009; 20:235605. [PMID: 19451682 DOI: 10.1088/0957-4484/20/23/235605] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/27/2023]
Abstract
A c-axis highly oriented sandwiched film composed of single-crystalline rutile TiO(2) on SnO:F (FTO) substrate was fabricated by a simple hydrothermal technique. The sandwich structure of the TiO(2) film was found to be constructed by two layers of TiO(2) nanorods, which grew towards both directions of the bulk solution and the substrate, respectively. One TiO(2) nanoparticle interlayer between them acted as the 'seed' layer. The length and the density of the TiO(2) nanoarrays could be tuned by varying the experimental parameters such as temperature and time. The resultant TiO(2) films showed a specific superhydrophilicity without any prior UV irradiation, which can be kept for a long period of time.
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Affiliation(s)
- Yangang Han
- Department of Polymer Science and Engineering, Key Laboratory of Macromolecule Synthesis and Functionalization of Ministry of Education, Zhejiang University, Hangzhou 310027, People's Republic of China
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