Download or read book Influence of Different Conditions on the Precipitation of Metatitanic Acid to Synthesis Rutile TiO2 via Sulfuric Acid Process written by and published by . This book was released on 2016 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Structures and Properties of Metatitanic Acid on Preparation Rutile Titanium Dioxide Pigment Via Short Sulfate Process written by Congxue Tian and published by . This book was released on 2017 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: The crystal structure, particle size distribution and impurity content of metatitanic acid had great impacts on the structures and pigment properties of rutile titanium dioxide pigment, and appropriate structure of metatitanic acid was helpful to prepare titanium dioxide with excellent pigment properties. The rutile titanium dioxide white pigment was produced via short Sulfate Process from unenriched low concentration industrial TiOSO4 solution. In order to produce rutile TiO2 pigment with good structures and excellent pigment properties, the crystal size of metatitanic acid should be controlled less than 8.9 nm and as close as possible to 7.9 nm, which could effectively promote the phase transformation and crystal growth of the rutile TiO2. The appropriate particle size distribution of metatitanic acid had obvious effects on obtaining rutile TiO2 with narrower particle size distribution and near 0.20 u00b5m. It was best to adjust the hydrolysis conditions to reduce the specific surface area of metatitanic acid so as to reduce the iron ion impurity adsorption.

Download or read book Orthogonal Interactions and Synergistic Effects of Salt Treatment and Calcination on Rutile Titanium Dioxide Pigment Preparation written by Congxue Tian and published by . This book was released on 2017 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Rutile titanium dioxide pigments were prepared by using metatitanic acid as raw material hydrolyzed from industrial low concentration titanyl sulfate solution via short sulfate process. The orthogonal interactions of the addition of salt treatment agent (ZnO, K2O, P2O5) and the highest calcination temperature were investigated by using four-factor quadric orthogonal regression test. The metatitanic acid and rutile TiO2 were characterized by XRD, particle size distribution and pigment properties test. The different salt addition and the highest calcination temperature had great effects on the achromatic power (TCS) of the rutile TiO2 pigments. The orthogonal interactions regression model to TCS was built and showed highly repeatability and stability, which could be used to forecast the pigment properties and preset the salt treatment and calcination conditions. And the optimal salt treatment conditions were ZnO of 0.36%, K2O of 0.70%, P2O5 of 0.20%, and the highest calcination temperature of 850 0C.

Download or read book Advances in Chemical Material and Metallurgical Engineering written by Jian Min Zeng and published by Trans Tech Publications Ltd. This book was released on 2013-01-11 with total page 4472 pages. Available in PDF, EPUB and Kindle. Book excerpt: Volume is indexed by Thomson Reuters CPCI-S (WoS). The 5 volumes set contains selected, peer reviewed papers from the 2012 2nd International Conference on Chemical, Material and Metallurgical Engineering (ICCMME 2012), December 15-16, 2012, Kunming, P.R. of China. The ICCMME series provide the most up-to-date and authoritative knowledge from both industrial and academic worlds, sharing best practice in the field of Chemical Engineering, Chemistry, Materials and Materials Processing and Metallurgical Engineering. The meeting provided an opportunity to highlight recent developments and to identify emerging and future areas of growth in these exciting fields.

Download or read book Synthesis of Rutile from Domestic Ilmenites written by G. W. Elger and published by . This book was released on 1974 with total page 28 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Conversion of Ilmenite to Rutile by a Carbonyl Process written by Aarne Visnapuu and published by . This book was released on 1973 with total page 28 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Production of High purity Synthetic Rutile from a Domestic Ilmenite Concentrate written by G. W. Elger and published by . This book was released on 1971 with total page 18 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book The Synthesis of Nano TiO2 Particles Using a DC Transferred Arc Plasma Reactor written by Xiaohong Liao and published by . This book was released on 2011 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: The effect of quench conditions on the properties of titanium dioxide produced using atransferred arc process was studied. Rutile phase TiO2 in the form of micron sized powder wasdecomposed and vaporized in a continuous feed DC transferred arc system. The hot gas streamexiting the reactor contained a mixture of the decomposition products of titania includingtitanium suboxides (TiO, Ti2O3), argon (Ar), and oxygen (O2). Rapid quenching of this gasstream with dry air resulted in the production of a titania aerosol. Collection of the product tookplace in the filtration system. The quench conditions studied included pre-quenchtemperature, T1, quench rate, Rq, residence time, tau, and operating power, Ptorch . Thecharacterization of particles includes phase identification, phase content calculation, sizedistribution analysis, elemental composition analysis, and morphology examination. The range of quench conditions studied were as follows, 1300

Download or read book Hydrolysis Conditions on Rutile Titanium Dioxide White Pigment Preparation Via Low Concentration TiOSO4 Solution written by Congxue Tian and published by . This book was released on 2017 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Using low concentration industrial titanyl sulfate solution as raw material, rutile titanium white pigment was prepared via the self-seeded thermal hydrolysis sulfate process. The effects of pre-adding water, feeding rate and aging time on the particle morphologies, particle size distribution and pigment properties of rutile titanium dioxide white pigment were investigated. The as-prepared samples were characterized by particle size distribution test, SEM, XPS, TEM and pigment properties test. The results showed that the optimal hydrolysis operating conditions was the pre-adding water ratio of 22% of, the feeding rate of 8.3 r/min, and the aging time was of 30min. The obtained rutile titanium white pigment was with suitable particle size, narrow particle size distribution and good pigment properties. The effects order on the pigment performances from large to small was the pre-adding water volume ratio, the feeding rate and the aging time.

Download or read book High Pressure Studies of Nanostructured TiO2 and Li4Ti5O12 Using Raman Spectroscopy and Synchrotron X ray Radiation written by Fengpin Xiao and published by . This book was released on 2015 with total page 216 pages. Available in PDF, EPUB and Kindle. Book excerpt: Nanomaterials have been extensively studied due to their distinctive properties such as surface effect, small-size effect and quantum size effect. In recent year, investigations of the structural and phase transformations of nanomaterials under high pressure are receiving increasing attentions. In addition to composition and synthetic routes, pressure provides a clean way to adjust interatomic distance and hence affect the crystal structure and thus properties of the nanostructured materials. Two nanomaterials (i.e. TiO2 and Li4Ti5O12) with different morphologies are studied in this thesis. In part I, the high-pressure behaviours of four hydrothermal synthesized 1D rutile TiO2 nanomaterials (i.e. nanowires, nanorods, flower-like nanorods and nanotubes) were studied using Raman spectroscopy and synchrotron X-ray diffraction for the first time. A new morphology of flower-like nanorods was the first time obtained by this synthesis method. The phase transition sequence of these four 1D rutile TiO2 nanomaterials is consistent with previous study. However, an interesting high-pressure behaviour was observed on nanowires that the reflection of rutile phase was observed in all patterns upon compression and decompression, suggesting a unique phase transition phenomenon unprecedented in TiO2 nanomaterials. Comparative studies of these 1D rutile TiO2 nanomaterials show strongly contrasting morphology-dependent compression behaviours: (1) Upon compression, nanotubes show the highest phase transition pressure of 20.8 GPa. (2) A higher compressibility along a-axis was observed compared to c-axis. (3) A relatively low bulk modulus of TiO2 nanotubes (bulk modulus of 193 GPa) was found indicating that among these 1D rutile TiO2 nanomaterials, nanotubes has the highest compressibility. In part II, another titania based energy material: nanostructured Li4Ti5O12 has been studied under high pressure. Nanostructured Li4Ti5O12 (LTO) as promising anode materials in lithium ion battery (LIB) has shown excellent yet morphology-dependent performance in LIB operations. However, the structural origin that influences the material performance at microscopic level remains unclear. Here using combined in situ Raman spectroscopy and synchrotron X-ray diffraction, we comparatively investigated the structural stability of two nanostructured LTO materials with different morphologies by application of external pressure up to 27 GPa. In particular, nanoflower-like Li4Ti5O12 spheres (LTO-1) and Li4Ti5O12 nanoparticles (LTO-2) were rendered to high pressures using diamond anvil cells and their structural evolutions were characterized upon compression and decompression. Raman measurements show that both LTO materials undergo pressure-induced structural disorder but with different reversibility upon decompression. X-ray results further confirmed Raman measurements, but also allow the quantitative analysis of pressure dependence of crystal structures. Structural refinements of diffraction patterns yield morphology dependent bulk modulus of the two LTO materials, which reveals critical information about the intrinsic lattice strain and vacancies. These different structural characteristics, when compared with another spinel structure of lithium titanium dioxide, allows the interpretation of different performance between LTO-1 and LTO-2 for LIB operations. This study thus contributes to the understanding of the important factors that may influence the electrochemical performance and help with the design of new LTO based anode materials for LIB.

Download or read book Modelling Growth of Rutile TiO2 written by Louis J. Vernon and published by . This book was released on 2010 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: TiO2 is a well investigated material due to its vast array of applications, from the most common white food colouring, to usage as an optical coating due to its high refractive index. When deposited as a thin?lm for use in solar control coatings using a magnetron sputtering device, TiO2 is found to form in rutile, anatase and amorphous phases, with the rutile (1 1 0) and anatase (1 0 0) crystal surfaces occurring most frequently. While the in?uence of deposition rate, substrate bias voltage, oxygen partial pressure and temperature have all been investigated experimentally, there are fewer simulated results. This seems to be primarily due to the lack of a suitable empirical potential through which dynamics can be accurately modelled. In this research project, the short-comings of the leading?xed and variable charge TiO2 potentials were revealed through comparison of binding energies and transition barriers for simple ad-clusters and interstitials to DFT. This led to the development of an improved variable charge potential, particularly when modelling the rutile (1 1 0) surface. It has been experimentally demonstrated that rutile growth results in a reduced surface due to the formation of large numbers of Ti interstitials and this was also suggested due to low Ti interstitial formation barriers found using DFT and the variable charge empirical potentials. The high interstitial formation probability was con?rmed when performing large numbers of Tix Oy depositions at typical industrial energies. Correlations between impact site and numbers of interstitials and vacancies formed were found along with insight into typical penetration depths and common defect structures. Multilayer growth was successfully modelled using classical MD by accelerating the deposition rate. The large numbers of formed interstitials coupled with a high escape barrier resulted in defective growth and so it was necessary to increase the substrate temperature such that atoms were mobile on the computational time-scale. Multilayer growth was investigated as a function of deposition energy, cluster composition and stoichiometry on the rutile (1 1 0), anatase (1 0 0) and amorphous surfaces. The optimum conditions for forming defect free rutile were found along with more limited insight into the ideal growth conditions when depositing on anatase and amorphous substrates. Finally a long time-scale dynamics technique, the?on-?y-kinetic Monte Carlo? method, was developed, and using an e?cient bespoke transition search algorithm, rutile TiO2 growth was successfully modelled at 350 K, with some caveats to avoid becoming entrenched in low activation di?usion processes. The?nal conclusion being that low energy depositions of large clusters with an oxygen excess would produce optimum?lm growth.

Download or read book Anatase to Rutile Transition in Titanium Dioxide Photocatalytic Nanomaterials written by Ciara Byrne and published by . This book was released on 2019 with total page 129 pages. Available in PDF, EPUB and Kindle. Book excerpt: Anatase and brookite are both considered metastable phases and transition irreversibly into the thermodynamically stable rutile phase at elevated temperatures (600-700°C in pure synthetic TiO2). Anatase TiO2 is widely accepted as the most photocatalytically active phase. However, TiO2 is only active under Ultraviolet (UV) light (~4% sunlight). A chemical precursor modifier, chemical additive or dopant can be used to alter the transition temperature and increase the photocatalytic activity of TiO2. These chemical additives/dopants/modifiers can result in a higher transition temperature and photocatalytic activity. However, some additives/dopants/modifiers have been known to reduce both. This work examined the effects benzoic acid, tungsten and boron nitride had on the transition temperature and the photodegradation of 1,4-dioxane. Benzoic acid and tungsten doping all increased the transition temperature compared to the control, with anatase still present at 800°C and 950°C respectively. All doped boron nitride samples were 100% rutile by 700°C, however the 0% BN-TiO2 was 100% rutile from 600°C. There were varying results when examining the percent removal of 1,4-dioxane. Benzoic acid, tungsten and boron nitride showed increased photocatalytic activity. Out of all of the samples examined, only 3 samples showed 100% removal of 1,4-dioxane, these were 2% W-TiO2, 4% W-TiO2 and 8% W-TiO2 at 800°C. When comparing the results for the transition temperature and photocatalytic activity of all dopants studied, 8% W-TiO2 is considered the optimim dopant and concentration. This is due to 26% anatase still being present at 950°C and it showed 100% and ~80% 1,4-dioxane removal when calcined at 800°C and 900°C respectively. The current investigation therefore showed that using the sol-gel method for doping with tungsten, benzoic acid and boron nitride successfully improved the anatase to rutile transition temperature and photocatalytic activity of TiO2.

Download or read book Mechanistic Studies of Titanium Dioxide and Ruthenium Atomic Layer Deposition by in Situ Techniques written by Rungthiwa Methaapanon and published by . This book was released on 2013 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: The demand of smaller, higher capacity and higher performance devices in microelectronics has driven the necessity of uniform, conformal, and pinhole-free thin film production. Furthermore, the design toward more complex structures and higher aspect ratios requires the processes to be highly controllable, down to the nanoscale. Atomic layer deposition (ALD) is a powerful technique that produces thin films with these desired properties, through a series of alternating self-limited surface reactions. The self-saturated nature of the technique allows for precise thickness control at the atomic scale. Despite increasing interest in ALD, there is still a lack of understanding of the mechanisms behind the process at a molecular level. The nucleation and growth fundamentals are crucial for better control and development of the process and, hence, need to be systematically studied. Due to the vulnerability of the reactions to ambient conditions, ex situ analysis techniques alone may not provide complete information on the surface chemistries needed to elucidate the mechanisms governing the processes. In situ analysis techniques, which allow surface investigation without disruption from contaminants and other species, are required. Therefore, in this work we have designed and constructed various in situ systems for this purpose. The in situ systems are ALD reactors integrated with different analysis tools, able to operate as fully functional deposition system so as to replicate the actual conditions of typical ALD reactors. Through in situ X-ray photoelectron spectroscopy (XPS), we studied ALD of TiO2 at 100 °C using titanium tetrachloride (TiCl4) and water (H2O) on two different surfaces. The initial growth rate on hydroxyl-enriched silicon dioxide (SiO2) is found to be higher than on hydrogen-terminated silicon. The XPS results provide evidence of Si-O-Ti bonds on the SiO2 surface and Si-Ti bonds on the hydrogen-terminated Si surface, without a trace of interfacial oxide. However, a silicon oxide layer forms at the interface between Si and TiO2 after vacuum annealing, concurrent with the reduction of TiO2. The results hence suggest TiO2 as an oxygen source for silicon oxidation under these conditions. In addition, we studied ruthenium thermal ALD using a new precursor, bis(2,4-dimethylpentadienyl) ruthenium, and oxygen. The process is achievable at a low operating temperature of 185 °C. Variation in the exposure time and pressure of oxygen has significant effects on the nucleation, growth rate and composition of the deposited ruthenium films. We propose that the subsurface oxygen formation, which involves slow diffusion of oxygen, is a rate-limiting step in the RuO2 formation process. The crystal growth and structures of Ru and RuO2 deposited on amorphous SiO2 by the same ALD process were measured by ex situ and in situ synchrotron X-ray diffraction. Interestingly, in situ XRD studies reveal that RuO2 films initially nucleate as metallic Ru crystallites. The hindered formation of subsurface oxygen in small nanocrystals is hypothesized as the cause that prohibits the growth of the initial oxide. Although metallic ruthenium films are textured with a (002) preference in the growth direction, RuO2 films nucleating on the metallic Ru nanoparticles have no preferential orientation. We also studied surface chemistries of Ru reactions during half ALD cycles via in situ synchrotron photoemission spectroscopy (PES). After long oxygen exposures, Ru oxide and carbon-oxygen species, which localize near the top surface, were detected. The peak intensities of these species noticeably decreased after reaction with the Ru precursor, indicating the reactions of Ru precursor with both O-Ru and O-C species. In brief, we fabricated and utilized in situ ALD/analysis systems, together with ex situ analysis tools, for studies of TiO2 ALD and Ru/RuO2 ALD. The studies not only demonstrate the power of the in situ systems for mechanistic studies, but also provide information on possible bond formation, surface reactions, and nucleation and growth mechanisms in the ALD processes.

Download or read book Synthesis Effects on Grain Size and Phase Content in the Anatase rutile TiO2 System written by Kimberly A. Farrell and published by . This book was released on 2001 with total page 110 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book EFFECTS OF HEAT TREATMENT CONDITIONS ON MORPHOLOGY OPTICAL PROPERTIES AND PERFORMANCE OF TiO2 IN DYE SENSITIZED SOLAR CELLS written by and published by . This book was released on 2018 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Abstract : This study primarily focuses on the synergistic effect between anatase and rutile in the photoanode of dye-sensitized solar cells (DSC), which was evaluated by tuning their phase ratio and crystallite size within the TiO2 photoanode via adjusting the sintering temperature and atmosphere. Hydrogenation of TiO2 powder was performed to increase visible light absorption to compare with air treated powders. Characterization of heat treated powders was performed using XRD, FE-SEM, S-TEM, BET, UV-vis, Fluorescence spectroscopy, and electrochemical I-V testing. The synergistic effect was effectively promoted in air treated TiO2 but was not observed using hydrogenation conditions. The highest energy conversion efficiency of 7.1% was found to occur with the photoanode sintered in air at 600°C for 2 hours, which possessed a crystallite size of 24.4 nm for anatase and 42.0 nm for rutile with 19.4 wt. % rutile. The highest efficiency obtained using hydrogenated TiO2 was 6.3% with morphology similar to the baseline P25 TiO2 which possessed a crystallite size of 21.4 nm for anatase and 36.4 nm for rutile with 11.6 wt. % rutile. Increased hydrogenation temperature resulted in decreased photovoltaic performance due to vacancy induced recombination centers and deteriorated phase junctions, despite increased visible light absorption measured in UV-vis. Hydrogenation was shown to significantly increase transformation rate of anatase to rutile and crystal growth beyond the transition temperature due to reduced crystal rigidity.

Download or read book Introduction to Photocatalysis written by Yoshio Nosaka and published by Royal Society of Chemistry. This book was released on 2019-03-07 with total page 272 pages. Available in PDF, EPUB and Kindle. Book excerpt: Presenting the basic science of semiconductor photocatalysis together with the various practical applications, this textbook is ideal for graduate students. It covers fundamental principles and applicable techniques of light, solid state physics, electrochemistry, reaction kinetics, and materials processing. A solid understanding of semiconductor photoelectrochemistry is developed through discussing the basic properties of a representative photocatalytic material, TiO2; the basic science of the light absorption phenomenon and the application to the powder suspension useful for the photocatalytic research; and the electronic state of semiconductors. Following this, the textbook moves on to explore photoelectrochemistry; the mechanism and kinetic analysis of photocatalytic reactions; typical fabrication methods of common photocatalysts and the factors for improving photocatalytic activity; and evaluation methods of photocatalytic activity. The textbook concludes by looking at the future prospects of the applications of photocatalysis. This introductory textbook provides a foundation in photocatalysis to supplement graduate courses in catalysis, environmental science, materials science and chemical engineering.

Download or read book Synthesis of TiO2 rutile by Vapor Transport written by Robert Heiting and published by . This book was released on 1971 with total page 180 pages. Available in PDF, EPUB and Kindle. Book excerpt: