2242 results about "Anatase" patented technology

The invention relates to a method of preparing a solution containing colloidal particles which contain crystalline titanium dioxide wherein one or more hydrolysable titanium-containing compound(s) is stabilised by oxalic acid in a reaction medium. The reaction further relates to the preparation of titania materials (including particulate materials, coating solutions and films) which comprise or include anatase phase titania, and so are suitable in photocatalytic applications. The invention also deals with a method of preparing B-phase titania.

The invention provides a method for preparing a titanium dioxide nano belt, belonging to the nano material technical field. The prior methods for preparing the titanium dioxide nano belt comprise the hydro-thermal method and the combination method of the sol-gel method and the hydro-thermal method. The prior electrostatic spinning method is applied to the preparation of nano fibers. The invention comprises three steps that: 1. a spinning solution is prepared; the mixture of polymethylmethacrylate and vinylpyrrolidone is used as a macromolecule template, and the mixture of chloroform and N,N-dimethylformamide is used as a solvent; 2. a titanium alkoxide/ macromolecule template compound nano belt is prepared; the electrostatic spinning method is used, and the technical parameters are as follows: the voltage is between 15 and 25kV and the curing distance is between 15 and 30cm; 3. a TiO2 nano belt is prepared; the heat treatment method is used, and the technical parameters are as follows: the rate of temperature rise is between 0.5 and 2 DEG C/min and the heat preservation time at the temperature of between 500 and 900 DEG C is between 10 and 15h; for the TiO2 nano belt prepared, the width is between 5 and 15mu m, the thickness is between 30 and 60nm and the length is more than 200mu m; the TiO2 nano belt comprises a pure phase anatase type TiO2 nano belt and a pure phase rutile type TiO2 nano belt.

The invention relates to a kieselguhr-based porous ceramics, a preparation method thereof and a method for loading Ag doped with nano TiO2 on the same, belonging to the technical field of a kieselguhr inorganic material. The kieselguhr-based porous ceramics is made from kieselguhr, a sintering auxiliary agent, a dispersing agent, a binder and water in the weight ratio of 60-92:8-40:0.01-2:0:001-1:100-450. The kieselguhr-based porous ceramics has functions of absorption and filtration, and can absorb granules in fluid when the fluid passes through the lieselguhr-based porous ceramics. Ag doped with nano TiO2 is loaded on the kieselguhr-based porous ceramics to generate kieselguhr-based porous ceramics loading the Ag doped with TiO2. The laden anatase-type nano TiO2 has large specific surface area. The effects of filtration, photochemical catalysis and sterilization of the kieselguhr-based porous ceramics loading the Ag doped with nano TiO2 are greatly increased.

One of many universal requirements of dental or orthopedic implants, wherever they are used in the vital body, is that the implant system should be biologically functioning. To achieve the biological functionality, the implant should meet several requirements for compatibility. These include biological compatibility and mechanical compatibility. It has now been recognized that morphological compatibility and crystallographic compatibility should be added to these two compatibility requirements. Hence, the present invention provides a method of forming a certain type of crystalline structure of titanium oxide and controlled surface roughness to meet both morphological and crystallographic compatibilities. It has been further determined that a chemical treatment (using sodium hydroxide) alone or followed by in-air oxidation, or acid treatment (a mixed aqueous solution of hydrofluoric acid and nitric acid), followed by sodium hydroxide treatment, furthermore followed by in-air oxidation provide for advantageous surface modifications to create a complex mixture of rutile with anatase and/or brookite types of titanium oxide and provide a most favorable surface for wettability and an acceptable range of surface roughness.

A method for producing fine particles of metal oxide characterized in that metal halide is hydrolyzed in the presence of organic solvent. According to this invention, under hydrolysis of titanium tetrachrolide, anatase type titanium oxide can be obtained by selecting hydrophilic organic solvent, and rutile type titanium oxide can be obtained by selecting hydrophobic organic solvent.

A titanium dioxide films synthesizing method includes the step of coating a titanium film on the surface of a homogenous (or heterogeneous) substrate, and the step of using the titanium-coated substrate as anode in an electrolyte to synthesize an nano-structured titanium dioxide film with single anatase phase on the surface of the titanium film by employing electrochemical anodic oxidation at room temperature.

A general-use white color reflecting material, and a process for production thereof are provided. The white color reflecting material, without troublesome surface treatment such as formation of a reflective layer by plating, is capable of reflecting a near-ultraviolet ray of a wavelength region of 380 nm or longer or a near-infrared ray sufficiently without light leakage; does not become yellow even when exposed to near-ultraviolet rays; has excellent lightfastness, heat resistance, and weatherability; has high mechanical strength and chemical stability; is capable of maintaining a high degree of whiteness; and is easily moldable at a low cost. Further a white color reflecting material used as an ink composition for producing the white color reflecting material in a film shape is also provided. The white color reflecting material comprises; a silicone resin or silicone rubber formed from titanium oxide-containing silicone composition, in which anatase-type or rutile-type titanium oxide particles are dispersed.

A photoelectrocatalytic oxidizing device having a photoanode being constructed from a conducting metal such as Ti as the support electrode. Alternatively, the photoanode is a composite electrode comprising a conducting metal such as Ti as the support electrode coated with a thin film of sintered nanoporous TiO₂. The device is useful in methods for treating an aqueous solution such as groundwater, wastewater, drinking water, ballast water, aquarium water, and aquaculture water to reduce amounts of a contaminant. The method being directed at reducing the amount and concentration of contaminants in an aqueous solution comprising providing an aqueous solution comprising at least one contaminant, and, photoelectrocatalytically oxidizing the contaminant, wherein the contaminant is oxidized by a free radical produced by a photoanode constructed from an anatase polymorph of Ti, a rutile polymorph of Ti, or a nanoporous film of TiO₂.

The present invention involves increasing the quantum efficiency in titania photocatalysts for photocatalytic (oxidation of acetaldehyde) and photosynthetic (photosplitting of water) reactions by integrating the titania photocatalyst with a polar mineral having surface electrical fields due to pyroelectric and piezoelectric effects, and by adjusting the nanostructure of the photocatalyst materials. The photocatalytic reactivity of titania powder is increased due to the effect of electric field present on the surface of polar mineral material on the photocatalytic effect of commercial titania with respect to photolysis of water. Additionally, the photocatalytic performance of pure phase rutile and anatase nanostructures with well defined morphologies was found to improved with respect to certain photocatalytic reactions in comparison with non-structured titania.

The present invention belongs to the field of inorganic metal oxide, and is especially process of preparing nanometer titania/silica photocatalyst sol and transparent photocatalyzing film. The anatase type nanometer titania/silica photocatalyst sol is prepared with inorganic low concentration titanium compound solution as material at normal pressure and 40-100 deg.c. The sol has high hydrophilicity, high photocatalyzing activity, high transparency and particle size of 15-30 nm. The sol may be painted onto substrate of different properties to form self-cleaning transparent photocatalyzing film with high hardness and high antifouling and antiseptic performance. The sol has high stability, small and homogeneous size and high performance; and the preparation process has low cost and simple operation and is suitable for large scale production and application.

The invention is directed to a catalyst having activity under the irradiation of a visible light, the catalyst being an oxide semiconductor such as an anatase type titanium dioxide, having stable oxygen defects. A method for producing a catalyst having activity under the irradiation of a visible light which comprises treating an oxide semiconductor with hydrogen plasma or with a plasma of a rare gas element, comprising performing the treatment in a state substantially free from the intrusion of air into the treatment system is also provided. An article comprising a base material having the catalyst above provided on the surface thereof and a method for decomposing a substance, comprising bringing an object to be decomposed into contact with the catalyst above under the irradiation of a light containing at least a visible radiation are disclosed. A novel photocatalyst which enables use of a visible radiation is provided, as well as a method utilizing the photocatalyst for removing various substances containing an organic matter or bacteria by photodecomposition.

Provided is a variable resistance element capable of performing a stable resistance switching operation and having a favorable resistance value retention characteristics, comprising a variable resistor 2 sandwiched between a upper electrode 1 and lower electrode 3 and formed of titanium oxide or titanium oxynitride having a crystal grain diameter of 30 nm or less. When the variable resistance 2 is formed under the substrate temperature of 150° C. to 500° C., an anatase-type crystal having a crystal grain diameter of 30 nm or less is formed. Since the crystalline state of the variable resistor changes by applying a voltage pulse and the resistance value changes, no forming process is required. Moreover, it is possible to perform a stable resistance switching operation and obtain an excellent effect that the resistance fluctuation is small even if the switching is repeated, or the variable resistance element is stored for a long time under a high temperature.

The invention relates to a preparation method of an ultra-thin titanium dioxide nanosheet. The ultra-thin titanium dioxide nanosheet is synchronized by using a wet chemical method. The synchronized titanium dioxide nanosheet is of an anatase titanium type and mainly square, rectangular and other irregular shapes, and the thickness of the ultra-thin titanium dioxide nanosheet in the [001] crystallographic orientation is 0.5-5.0 nanometers; and (001) crystal surfaces with high reactivity are arranged on the upper bottom surface and the lower bottom surface of the ultra-thin titanium dioxide nanosheet. The titanium dioxide nanosheet with the structure has important application in the fields of environmental science and new energy.

A process for preparing the crystal phase controllable TiO2 nanocrystals includes such steps as hydrolyzing the Ti-cotnained compound in the aqueous solution of alcohol to obtain amorphous TiO2 powder, adding inorganic acid, hydrothermal treating, filtering, washing and drying. Its resultant TiO2 nanocrystal has the continuously regulatable ratio of anatase phase to rutile phase.

The invention discloses a preparation method for a two-dimensional sheet-shaped titanium dioxide nanosheet material. The preparation method comprises the following steps: soaking three-dimensional laminated Ti3AlC2 powder in an aqueous solution of HF at a room temperature, and removing an Al atom layer by use of a chemical liquid-phase dissection method to prepare a two-dimensional Ti3C2 nanosheet with laminated characteristics still kept; then, placing Ti3C2 in a tubular furnace, ventilating a gas mixture of flowing oxygen gas and argon gas after vacuumizing, realizing in-situ oxidization of the two-dimensional Ti3C2 nanosheet at a high temperature, then cooling, taking out powder, and grinding to obtain the TiO2 nanosheet. According to the preparation method disclosed by the invention, any organic solvent and additive are not needed to be added in the preparation process, process parameters are stable, the procedure is simple, the process is controllable, the efficiency is high and the cost is low; the prepared two-dimensional titanium dioxide nanosheet has transverse dimension of 5-10 microns, and single-layer average thickness of 50 nanometers; the prepared rutile type titanium dioxide nanosheet is high in purity and good in degree of crystallinity, and only contains very little antase phase.

The invention relates to a method for preparing extrafine anatase titanium dioxide nano rods, which comprises that: (1) titanium containing inorganic substances are hydrolyzed, the temperature is raised to be between 20 and 100 DEG C, inorganic base solution is added for heat preservation and hydrolysis and neutralizes pH to between 7 and 8, and precipitation of hydrous titanium dioxide is obtained; (2) the precipitation is repeatedly washed, added with oxyful, stirred and subjected to ultrasonic dispersion, the temperature is raised to be between 0 and 50 DEG C and the heat is preserved for 1 to 24 hours; and (3) water solution of pertitanic acid is diluted by deionized water, then filled into a hydrothermal reaction kettle, subjected to hydrothermal treatment at a temperature between 100 and 250 DEG C for 2 to 48 hours, and cooled to room temperature. The preparation method is simple; the obtained sol does not contain organic stabilizer; and the titanium dioxide in the sol is anatase, has a rod-shaped structure and high length-diameter ratio, and can form extrafine rod-shaped nanocrystal titanium dioxide.

The present invention concerns the deposition of fluorine modified, titanium dioxide films (TiO2) onto hot glass by atmospheric pressure chemical vapor deposition (APCVD) using TiCl4 vapor. The invention is also suitable for depositing other metallic oxide films from their metallic halides such as SnCl4, GeCl4, and VCl4. The present invention provides a process that deposits a novel, fluorine modified, titanium dioxide film (TiO2) onto hot glass by atmospheric pressure chemical vapor deposition using TiCl4 vapor. The process uses injection of TiCl4 into a hot, nonoxygen containing carrier gas and blends the carrier gas and TiCl4 vapor with an oxygen containing gas stream containing a haze reducing quantity of a fluorine containing compound before contacting a surface of hot glass with the blended mixture. The process is capable of depositing a fluorine modified, TiO2 film at deposition rates exceeding 900 Å per second. The crystalline phase of the fluorine modified film is essentially anatase. The film has a haze of less then 1% and a refractive index of greater than or equal to about 2.48. Also provided is an apparatus for practicing the process and a novel coated glass.

Mixed-phase TiO₂ nanofibers prepared via a sol-gel technique followed by electrospinning and calcination are provided as photocatalysts. The calcination temperature is adjusted to control the rutile phase fraction in TiO₂ nanofibers relative to the anatase phase. Post-calcined TiO₂ nanofibers composed of 38 wt % rutile and 62 wt % anatase exhibited the highest initial rate constant of UV photocatalysis. This can be attributed to the combined influences of the fibers' specific surface areas and their phase compositions.

The invention relates to a preparation method of echinoid titanium dioxide microspheres in single/double layer cavity structure, belonging to the field of nano composite materials. The method comprises the following steps: (1) preparing monodisperse silicon dioxide microspheres with uniform particle size; (2) by using silicon dioxide as a template, coating a titanium dioxide layer on the surface of the silicon dioxide microspheres by using a sol-gel method to obtain core-shell type silicon dioxide/titanium dioxide composite microspheres; (3) regulating the concentration of sodium hydroxide solution, the hydrothermal reaction time and other conditions, and preparing echinoid titanium-base microspheres in the single/double layer cavity structure in a controllable way; and (4) treating the echinoid titanium-base microspheres in the single/double layer cavity structure with hydrochloric acid with a certain concentration, and calcining at high temperature to obtain anatase-type echinoid titanium dioxide microspheres in the single/double layer cavity structure. The material prepared by the method has the high-activity pure-phase titanium dioxide crystal structure, and has the advantages of large specific area, complete appearance and high yield; the technical process is controllable and easy to operate; and the invention also has the advantages of low preparation cost, no pollution and low energy consumption.

A process for preparing the nitrogen doped anatase-type TiO2 by hydrothermal synthesis includes such steps as proportionally mixing Ti source, precipitant, nitrogen source and water, loading in high-pressure reactor with teflon liner, hydrothermal reacting, alcohol washing, water washing, and drying.

An object of the present invention is to provide an electrode for electrolysis which is available by an easy fabrication process, can produce ozone water at high efficiency and also can produce hydrogen peroxide and OH radicals having a high oxidizing power by the electrolysis of water at a low current density; an electrolytic process using the electrode; and an electrolytic apparatus using them. The electrode for electrolysis according to the present invention has a substrate and a surface layer formed on the surface thereof, the surface layer being made of anatase type titanium oxide.