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Search theses and dissertations gathered from participating repositories worldwide. Every result links back to the library that holds it. No account is needed.
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Showing 1 to 20 of 103 for “"anatase"”.
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Investigation of defect formation and control in poly-crystalline anatase titanium dioxide
… been praised for the catalytic activity of its anatase phase, its abundance in nature, low toxicity, stability in aqueous environments and ease of processing. Among its drawbacks is a high native carrier concentration likely due to the formation of oxygen vacancies and their clustering at grain …
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Exploiting polar interfaces for photocatalytic water splitting: application to the anatase-cuprous oxide heterojunction
… surface polarity compensation mechanisms in the anatase (TiO2) / cuprous oxide (Cu2O) heterojunction, a system which has recently been realized in experiment. Due to its low valence band edge, anatase has a good oxidation potential; by contrast cuprous oxide has a good reduction potential due to …
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Density functional theory study of adsorption of cronconate dyes on TiO2 Anatase (010) and (100) surfaces
… behaviour of the two dyes on (010 and 100) anatase TiO2 surfaces were investigated in this study by employing first principle calculation based on DFT using a plane-wave pseudo potential method. The generalized gradient approximation (GGA) was used in the scheme of Perdew-Burke Ernzerhof to …
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The Effect of Zr-Doping and Crystallite Size on the Mechanical Properties of TiO2 Rutile and Anatase
… processes. The most abundant phases are rutile, anatase and brookite. In addition, there are a number of metastable low density modifications. The compression behavior of anatase and rutile was studied for TiO2 and Ti0.9Zr0.1O2 starting materials with crystallite size in the micro- and also …
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Computational study of low index surface of an anatase TiO2 doped with ruthenium (Ru) and strontium (sr) for application in Dye sensitized solar cells
… electronic and optical properties of bulk anatase TiO2, undoped, and ruthenium (Ru) and strontium (Sr) doped anatase TiO2 (1 0 0) surface. Two different doping approaches i.e., substitutional and adsorption mechanisms were considered in this study. The results showed that absorption band …
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Raman, Infrared, X-ray, and EELS Studies of Nanophase Titania
… phases investigated were amorphous titania, anatase TiO2, and rutile TiO2. Annealing-induced phase transformations from amorphous TiO2 to anatase to rutile were studied by Raman scattering, infrared reflectivity, infrared absorption, x-ray diffraction, and electron energy-loss spectroscopy …
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Synthesis and characterisation of Titania thin films
… amorphous; higher temperatures gave films of anatase. With increasing film thickness, the optical transmission decreased. The indirect optical band gap decreased with increasing deposition temperature, dropping from 3.47 eV to 3.23 eV. Effect of deposition time: TiO2 films were deposited on …
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Fabrication of TiO2 Films by Anodisation of Ti-Foils in Oxalic Acid
… anodisation voltage, GAXRD analysis showed that anatase was the only oxide phase in the samples anodised at voltages from 100 to 200 V (at 10 min for 0.2 M oxalic acid and current density 60 mA / cm^2). Data from Raman showed that anatase was present in all films and its intensity increased with …
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Nanostructured nitrogen and carbon codoped TiO2 thin films: synthesis, structural characterization and optoelectronic properties
… grains was obtained. However, at high pressures anatase phase became dominant and columnar structure was favored. Therefore, the anatase-rutile phase ratio as well as the microstructure of the films can be controlled by adjusting oxygen pressure and introducing N and C into the TiO 2 matrix. …
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Optimization of titanium dioxide (TiO2) thin film using dip coating technique for oxygen gas sensor
… detection of target gases. However, to obtain anatase phase for oxygen gas sensor with low and short annealing temperature is the obstacle in the fabrication of oxygen gas sensor. It is thus desirable to develop TiO2 thin film preparation technique that provides the anatase phase for oxygen gas …
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Titanium surface modification by oxidation for biomedical application
… sodium titanate forms over a layer of amorphous anatase and (2) a dense layer of rutile forms. For the high concentrations with increasing temperature, the model involves: (1) amorphous sodium titanate forms over a layer of amorphous anatase, (2) a dense layer of anatase forms and raises up the …
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On the phase transition and photo-reactivity on the micro-sized titanium dioxide single crystal.
… high-reactivity photocatalysts. This thesis, anatase TiO2 microcrystals are used to study the anatase-to-rutile phase transition (ART) process mechanism and compare the photo-reactivity to the bulk single crystals. Scanning Electron Microscopy (SEM), Raman Microscopy, and Photoluminescence …
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Structure-Sensitivity of CO Oxidation Over Supported Pt Catalysts in the Subnanometer Regime and Its Origin
… with the size of Pt particles supported on anatase TiO2 and CeO2 and its origin. We varied the Pt nuclearity from single-atoms to subnanometer clusters (0.8-0.9 nm) to small nanoparticles (1.5-1.8 nm). By coupling density functional theory calculations and microkinetic modeling with kinetic …
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Linear-Scaling Density Functional Theory and Theoretical Electron Energy Loss Spectroscopy Investigations of Surfaces and Defects in Nanomaterials
… associated with oxygen vacancy defects in the anatase (101) surface. These spectra are found to agree with the limited experimental data available. EEL spectra for nitrogen dopants in anatase are also predicted, based on literature geometries for these. The energetics of the oxygen vacancy is …
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Preparation of bioactive surface via gel oxidation on titanium for biomedical application (hip joint replacement)
… was introduced to convert sodium titanate into anatase to improve the bioactivity of titanium treated in argon atmosphere. Thus, four samples (AT-0.5-HT500R, AT-0.5-HT600R, AT-5-HT500R and AT-5- HT600R) with different ratios of anatase to rutile were produced by varying the concentration of HCl …
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Dynamics of liquids in porous media: Investigating competitive adsorption using NMR relaxometry
… catalysts and catalyst supports, namely anatase titania, γ-alumina and silica. The main NMR relaxometry method that was applied was Fast Field Cycling (FFC) NMR, which has been shown to quantitatively probe surface-adsorbate interactions of liquids in porous media. First, a model study of …
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Nanoscale heterojunctions of transition metal oxide and silicon for high-efficiency oxygen evolution reaction
… In particular, the heterojunction of anatase titanium dioxide (TiO₂) and Si is of our best interest. The heterojunctions of TiO₂ and Si have not only exhibit great synergies based on the bulk properties, but also have improved the photoelectrocatalytic efficiency experimentally. …
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SIDEROPHORE DESFERRIOXAMINE B PROMOTED DISSOLUTION AND ADSORPTION PROPERTIES OF TITANIUM DIOXIDE BEARING MINERALS
… different crystalline polymorphs of TiO2 such as anatase and rutile by siderophore desferrioxamine B (DFOB) in environmental conditions. Spectroscopic and microscopic techniques were used to understand their bioavailable nature at different pH. Dissolution of Ti from the surface of anatase and …
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Growth Study and Characterization of TiO2 Based Thin Films for Low Temperature Synthesis of Transparent Conductive Films
… (XRD) revealed a poor control over the anatase phase (mixed anatase and rutile phase formation) when the substrate was heated during the films growth, which degraded the films transport properties. The adjustment of the process pressure and substrate temperature enhanced the conductivity …
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