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TiO2 Nanotubes (tio2 + nanotube)
Terms modified by TiO2 Nanotubes Selected AbstractsPhotosensitization of TiO2 Nanostructures with CdS Quantum Dots: Particulate versus Tubular Support ArchitecturesADVANCED FUNCTIONAL MATERIALS, Issue 5 2009David R. Baker Abstract TiO2 nanotube arrays and particulate films are modified with CdS quantum dots with an aim to tune the response of the photoelectrochemical cell in the visible region. The method of successive ionic layer adsorption and reaction facilitates size control of CdS quantum dots. These CdS nanocrystals, upon excitation with visible light, inject electrons into the TiO2 nanotubes and particles and thus enable their use as photosensitive electrodes. Maximum incident photon to charge carrier efficiency (IPCE) values of 55% and 26% are observed for CdS sensitized TiO2 nanotube and nanoparticulate architectures respectively. The nearly doubling of IPCE observed with the TiO2 nanotube architecture is attributed to the increased efficiency of charge separation and transport of electrons. [source] Nanotube Arrays: Template-Directed Liquid ALD Growth of TiO2 Nanotube Arrays: Properties and Potential in Photovoltaic Devices (Adv. Funct.ADVANCED FUNCTIONAL MATERIALS, Issue 9 2010Mater. X. Hu, A. Sellinger, et al. present on page 1390 an array of TiO2 nanotubes prepared via a new liquid atomic layer deposition process in porous anodic alumina templates. The ability to reproduce the arrays on various types of substrates including Si and transparent conducting oxides opens opportunities in many exciting opto-electronic applications. The potential of such arrays in ordered bulk-heterojunction solar cells is explored. [source] Template-Directed Liquid ALD Growth of TiO2 Nanotube Arrays: Properties and Potential in Photovoltaic DevicesADVANCED FUNCTIONAL MATERIALS, Issue 9 2010Thelese R. B. Foong Abstract Dense and well-aligned arrays of TiO2 nanotubes extending from various substrates are successfully fabricated via a new liquid-phase atomic layer deposition (LALD) in nanoporous anodic alumina (AAO) templates followed by alumina dissolution. The facile and versatile process circumvents the need for vacuum conditions critical in traditional gas-phase ALD and yet confers ALD-like deposition rates of 1.6,2.2,Å cycle,1, rendering smooth conformal nanotube walls that surpass those achievable by sol,gel and Ti-anodizing techniques. The nanotube dimensions can be tuned, with most robust structures being 150,400,nm tall, 60,70,nm in diameter with 5,20,nm thick walls. The viability of TiO2 nanotube arrays deposited on indium tin oxide (ITO),glass electrodes for application in model hybrid poly(3-hexylthiophene) (P3HT):TiO2 solar cells is studied. The results achieved provide platforms and research directions for further advancements. [source] Microstructured Arrays of TiO2 Nanotubes for Improved Photo-Electrocatalysis and Mechanical StabilityADVANCED FUNCTIONAL MATERIALS, Issue 12 2009Daoai Wang Abstract The preparation of micropatterned TiO2 nanotubes (NTs) with tunable morphologies by combining laser micromachining technology and an anodization method is reported. The micropatterned structure can be easily designed and fabricated by laser micromachining a titanium substrate, further anodization of which gives nanotube arrays perpendicularly oriented to the titanium surface. The patterned TiO2 NTs show dramatically improved photocurrent and photocatalytic performances because of their enhanced surface area and light-harvesting capability. The photocurrent density and incident-photon-to-current efficiency at the peak absorption increases by 48 and 39%, respectively, compared to a TiO2 NT array without a patterned structure. It was also found that micropatterning dramatically improves the mechanical stability of the TiO2 NTs on the substrate, which otherwise were liable to peel off from the substrate surface. The strategy will reasonably expand the application of TiO2 NTs in a variety of fields that require enhanced photo-electrocatalysis and mechanical stability. [source] Photosensitization of TiO2 Nanostructures with CdS Quantum Dots: Particulate versus Tubular Support ArchitecturesADVANCED FUNCTIONAL MATERIALS, Issue 5 2009David R. Baker Abstract TiO2 nanotube arrays and particulate films are modified with CdS quantum dots with an aim to tune the response of the photoelectrochemical cell in the visible region. The method of successive ionic layer adsorption and reaction facilitates size control of CdS quantum dots. These CdS nanocrystals, upon excitation with visible light, inject electrons into the TiO2 nanotubes and particles and thus enable their use as photosensitive electrodes. Maximum incident photon to charge carrier efficiency (IPCE) values of 55% and 26% are observed for CdS sensitized TiO2 nanotube and nanoparticulate architectures respectively. The nearly doubling of IPCE observed with the TiO2 nanotube architecture is attributed to the increased efficiency of charge separation and transport of electrons. [source] Ordered Ferroelectric Lead Titanate Nanocellular Structure by Conversion of Anodic TiO2 NanotubesADVANCED MATERIALS, Issue 30 2009Jan M. Macak The novel synthesis of ferroelectric perovskite PbTiO3 layers is reported. For that, anodic self-organized TiO2 nanotubes are used as a template for deposition of Pb inside the nanotubes. Upon thermal annealing, the filled template is converted to desired perovskite structure with nanocellular architecture. This approach could be advantageously used for synthesis of other piezoelectric or composite materials. [source] A Novel Protocol Toward Perfect Alignment of Anodized TiO2 NanotubesADVANCED MATERIALS, Issue 19 2009Daoai Wang Perfectly aligned high-aspect-ratio TiO2 nanotubes that are perpendicularly oriented to a substrate are obtained using a two-step anodization process in ethylene glycol containing 0.5,wt% NH4F and 1,vol% HF, overcoming the bundling issue of TiO2 NTs commonly observed in conventional approaches. They are then used as a template for the electrodeposition of Pt nanowires. [source] Determination of trace organophosphorus pesticides in water samples with TiO2 nanotubes cartridge prior to GC-flame photometric detectionJOURNAL OF SEPARATION SCIENCE, JSS, Issue 14 2010Yunrui Huang Abstract This article described a new method for the sensitive determination of organophosphorus pesticides in water samples using SPE in combination with GC-flame photometric detection. In the procedure of method development, TiO2 nanotubes were used as SPE adsorbents for the enrichment of organophosphorus pesticides from water samples. Several factors, such as eluent and its volume, sample pH, sample volume, sample flow rate, and concentration of humic acid, were optimized. Under the optimal conditions, the proposed method had good linear ranges as 0.1,40,,g/L for each of them, LOD of 0.11, 0.014, and 0.0025,,g/L, and LOQs of 0.37, 0.047, and 0.0083,,g/L for chlorpyrifos, phorate, and methyl parathion, respectively. The proposed method was validated with real environmental water samples and the spiked recoveries were over the range of 86.5,115.1%. All these results indicated that TiO2 nanotubes, as a new SPE adsorbent, would be used widespread for the preconcentraiton and determination of environmental pollutants in the future. [source] Self-organized nucleation layer for the formation of ordered arrays of double-walled TiO2 nanotubes with temperature controlled inner diameterPHYSICA STATUS SOLIDI - RAPID RESEARCH LETTERS, Issue 5-6 2010Mihai Enachi Abstract It is proposed to use the variation of the electrolyte temperature to fabricate titania nanotubes with variable inner diameter at a constant outer diameter and an invariable package density. The anodization of Ti sheets in an ethylene glycol and HF containing electrolyte is found to allow the preparation of nanotubes with the inner diameter controlled in the range from 10 nm to more than 250 nm through the change of the electrolyte temperature from ,20 °C to +50 °C. The peculiarities of the anodization process performed at low electrolyte temperatures are discussed. (© 2010 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim) [source] A simple approach for synthesis of TiO2 nanotubes with through-hole morphologyPHYSICA STATUS SOLIDI - RAPID RESEARCH LETTERS, Issue 5 2009Krishna Kant Abstract The present work reports a simple approach for fabrication of self-standing titania (TiO2) nanotube membranes with through-hole morphology. The method is hydrofluoric acid free and the pore opening of TiO2 nanotubes is performed by electrochemical thinning of the oxide barrier layer. A reduction of anodization voltage was applied at the end of the anodization process to cause a successful removal of the remaining barrier layer from the TiO2 nanotubes during their detachment from the underlying titanium substrate. (© 2009 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim) [source] TiO2 nanotubes: photocatalyst for cancer cell killingPHYSICA STATUS SOLIDI - RAPID RESEARCH LETTERS, Issue 4 2008M. Kalbacova Abstract The present work reports on the use of self-organized TiO2 nanotube layers for the photocatalytic killing of cancer cells. TiO2 nanotube layers with different dimensions (diameter 50 nm and 100 nm, thickness 800 nm and 1.3 ,m, respectively) were grown by anodization of Ti. Upon low dose of UV irradiation, the vitality of cancer cells cultured on these nanotube layers was significantly affected , the cells reduced their shape and size and a significant amount of the dead cells was found. These results demonstrate that self-organized TiO2 nanotube layers can be used for photo-induced cancer cell killing. (© 2008 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim) [source] Towards ideal hexagonal self-ordering of TiO2 nanotubesPHYSICA STATUS SOLIDI - RAPID RESEARCH LETTERS, Issue 5 2007Jan M. Macak Abstract The present work reports on key factors that influence the degree of order in anodic TiO2 nanotube layers. We show that the anodization voltage and the Ti purity are of crucial importance for the ideality of self-organization within the nanotube layers and that repeated anodization can significantly improve hexagonal ordering. Optimizing each factor significantly reduces the variation in the average pore diameter and strongly reduces the areal density of polygon ordering/packing errors. (© 2007 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim) [source] The use of Ti meshes with self-organized TiO2 nanotubes as photoanodes of all-Ti dye-sensitized solar cellsPROGRESS IN PHOTOVOLTAICS: RESEARCH & APPLICATIONS, Issue 4 2010Yuanhao Wang Abstract This paper reports a simple and facile method for directly growing self-organized TiO2 nanotubular arrays around the whole Ti mesh by electrochemical anodization in organic electrolytes and their application in all-Ti dye-sensitized solar cells (DSSCs). Compared with the traditional fluorine-doped tin oxide (FTO)-based DSSC and the backside illuminated DSSC, this type of DSSC showed advantages such as low resistance, cheap fabrication cost and enhanced sunlight utilization. Different thicknesses of nanotubular array layers were investigated to find their influence on the photovoltaic parameters of the cell. We also considered three types of meshes as the substrates of anodes and found that the cell with 6,openings/mm2 exhibited the highest conversion efficiency of 5.3%. The area of the cell had only a little impact on the photovoltaic performances. Copyright © 2010 John Wiley & Sons, Ltd. [source] WO3/TiO2 Nanotubes with Strongly Enhanced Photocatalytic ActivityCHEMISTRY - A EUROPEAN JOURNAL, Issue 30 2010Indhumati Paramasivam Mixed oxide photocatalysts: WO3 - containing TiO2 nanotubes were prepared by self-organizing electrochemical anodization of TiW alloys (Ti,0.2,W see figure, and Ti,9,W). It is shown that a content of only 0.2,at,%,WO3 with respect to the titania nanotubes leads to a very significant increase of the photocatalytic reaction rate compared not only to pure anatase TiO2 nanotubes, but also in comparison with any other modified TiO2 nanotube system reported up to now. [source] | |||||||||||||