Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: KEGG:D01931 (TiO2)
11,320 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The pure titanium disks were divided into three groups and etched for 30 minutes with HNO3, hot H2SO4/H2O2 or hot H2SO4/HCl respectively. The treated disks were studied and analyzed with scanning electron microscope (SEM) and X-ray photoelectron spectroscopy (XPS). The disks etched with HNO3 had a smooth surface, while those etched with hot H2SO4/H2O2 or hot H2SO4/HCl had rough surfaces, and the surface etched with hot H2SO4/HCl had larger micropores. The XPS analysis demonstrated that the main elements of the surface in three groups were titanium, oxygen and carbon. The carbon concentration was the lowest on the surface etched with hot H2SO4/H2O2 and the highest on that etched with hot H2SO4/HCl. The substances were TiO2, Ti2O3, TiO and metal Ti on the surface etched with HNO3 or hot H2SO4/H2O2. Only TiO2 was detected on the surface etched with hot H2SO4/HCl.
...
PMID:[Effects of three different etching methods on surface morphology and element of pure titanium]. 1700 14

A new method has been developed for the determination of gold based on separation and preconcentration with a microcolumn packed with nanometer TiO2 immobilized on silica gel (immobilized nanometer TiO2) prior to its determination by flame atomic absorption spectrometry. The optimum experimental parameters for preconcentration of gold, such as pH of the sample, sample flow rate and volume, eluent and interfering ions, have been investigated. Gold could be quantitatively retained by immobilized nanometer TiO2 in the pH range of 8-10, then eluted completely with 0.1 mol L(-1) HNO3. The detection limit of this method for Au was 0.21 ng mL(-1) with an enrichment factor of 50, and the relative standard deviation (R.S.D.) was 1.8% at the 100 ng mL(-1) Au level. The method has been applied for the determination of trace amounts of Au in geological and water samples with satisfactory results.
...
PMID:Determination of gold by nanometer titanium dioxide immobilized on silica gel packed microcolumn and flame atomic absorption spectrometry in geological and water samples. 1799 31

The direct determination method of trace composition, Fe2O3, TiO2, MnO, K2O, Na2O, CaO and MgO, and impurity elements, Pb, Cr, Cd, Cu and As, in kaolin was studied by using inductive coupled plasma mass spectrometry (ICP-MS). After the samples were dissolved completely in HF-HNO3 at low temperature, silicon was volatilized in the form of SiF4 and separated from the solution. Then the solution was continually evaporated to dry to get the solid substance which was dissolved by the nitric acid (1+3). The internal elements 45Sc, 115In and 205Tl were added on line and the effect of matrix, interface and fluctuation of instrument was overcome effectively by using internal standard calibration method. By choosing the optional operating parameters and appropriate isotopes of element to be detected, the influence of mass spectrometry interference was conquered effectively. The effect of temperature in samples preparation on the determination of arsenic was tested. The recovery for spiking sample is in the range from 95.0% to 101.0% and the relative standard deviation is in the range from 1.1% to 2.01%. In order to check the accuracy of the method, the kaolin standard reference material GBW03122 was also analyzed, and the analytical values conformed to standard values. This method has the characteristics of being simple, rapid and accurate, and can be used in the testing of trace composition and impurity elements in kaolin and ceramic product.
...
PMID:[Study on the determination of trace composition and impurity elements in kaolin with ICP-MS]. 1944 38

An anatase TiO2 and three kinds of novel TiO2 nanoparticles were prepared by a hydrothermal method for dye-sensitized solar cells (DSSCs), which were obtained by mixing NaOH (10 M), KOH (14 M) and LiOH (10 M) solution with an anatase TiO2 powder, respectively. The TiO2 working electrodes of DSSCs were prepared and the photoelectric properties of the cells were characterized. The influence of different poly(ethylene glycol) contents in TiO2 films with and without HNO3 treatment on the electron transfer in DSSCs were investigated. It is found that the DSSC with HNO3 (0.002 mol/l)-treated film containing 16.7 wt% PEG shows the higher power conversion efficiency of 6.0%, which was mainly depended on the degrees of TiO2 pore size and uniformity of TiO2 films.
...
PMID:Enhanced efficiency of dye-sensitized solar cells with novel synthesized TiO2. 2035 13

A nano-structured film composed of TiO2 and reduced graphite oxide (GO) was synthesized on ITO glass via a typical electrochemical route. A mixed solvent of Ti(SO4)2 and GO was prepared, with the addition of H2O2, HNO3 and DMF at different ratio. A setup of two electrodes of ITO glass in a plastic cell and an electrochemical analyzer is used for the film forming. The film is characterized with a microstructure of GO plates being perpendicular to the glass substrate, since GO in the electrolyte solvent is separated as small plates at about several nanometers in diameter. TiO2 is found being deposited between these GO plates. This microstructure is quite different from the film formed by normal deposition, where the GO plates are generally parallel to the substrate. The oxygen containing groups of C=O, C-O-C and C-OH on the GO surface are reduced because of neighboring to TiO2, it means two phases being bonded to each other at the interface. The photoelectric current of the composite film is compared with the pure TiO2 film, the former one is almost one time higher than the latter one. The degradation of methyl orange of two kinds of film is also analyzed under the irradiation of ultraviolet light. The photocatalytic activity of two kinds of film presents the same trend of variation as that of photoelectric current. These results suggest that the photoexcited electrons of TiO2 may quickly transfer to the glass substrate through the reduced GO neighbor, that owns a better conductivity, and so far decrease the recovery of excited electron-hole. The unordinary microstructure of the composite film may favor both to the electron transmission between the GO and ITO glass substrate, and to the light excitation of TiO2. The microstructure of different films was studies by AFM, XPS, FESEM. The photo-electrochemical property was measured by an electrochemical instrument Model CHI660C with Blupoint4 as a UV light source.
...
PMID:Synthesis of TiO2/GO composite film via an electrochemical route. 2113 73

TiO2 films were prepared on glass substrates using the sol-gel process for a dye-sensitized solar cell application. The TiO2 sol was prepared using hydrolysis/polycondensation. Titanium (IV) Tetra Isopropoxide (TTIP) was used as precursor and Nitric acid (HNO3) was used as a catalyst for the peptization. The crystal structure and morphology of the prepared materials were characterized by XRD, and an SEM. The observations confirmed the nanocrystalline nature of the TiO2. The reaction parameters, such as the catalyst concentrations, the calcination time, and the calcination temperature were varied during the synthesis in order to achieve nanosize TiO2 particles. The prepared TiO2 particles were coated onto FTO glass using a screen printing technique. The prepared TiO2 films were characterized by UV-vis. The TiO2 particles calcinated at low temperatures showed an anatase phase they grew into a rutile phase when the calcination temperature increased. The size and structure of the TiO2 particles were adjusted to specific surface areas. It was found that the conversion efficiency of the DSSC was highly affected by the properties of the TiO2 particles.
...
PMID:Nanostructured TiO2 films for dye-sensitized solar cells prepared by the sol-gel method. 2240 37

Three-dimensional (3D) TiO2 hierarchical structures with various microstructures have been successfully synthesized via a surfactant-free and single-step solvothermal route, in which hydrochloric acid (HCl), nitric acid (HNO3), and acetic acid (HAc) are employed as the acid medium, respectively. The effects of acid medium on the microstructures and properties of 3D TiO2 hierarchical structure have been studied. The results indicate that 3D dandelion-like microspheres assembled of radial rutile nanorods are obtained in the sample prepared with HCl. Both the fraction of rutile and the diameter of nanorod enhance with the increasing HCl concentration. For the products derived from either HNO3 or HAc, 3D spheres composed of anatase nanoparticles are present. The 3D dandelion-like TiO2 hierarchical structures show low reflectance and efficient light harvesting since this ordered rod geometry offers a light-transfer path for incident light as well as multiple reflective and scattering effects. Moreover, 3D TiO2 with this unique topology shows superior photocatalytic activity despite low surface area, which can be ascribed to the enhanced light harvesting, fast electron transport, and low electron/hole recombination loss.
...
PMID:Effects of acid on the microstructures and properties of three-dimensional TiO2 hierarchical structures by solvothermal method. 2250 Sep 85

TiO2 nanofiber consisting of 15 +/- 5 nm anatase grains was synthesized by hydrothermal treatment of fibrous hydrogen titanate precursor at 180 degrees C for 20 h. The hydrogen titanate precursor was synthesized by hydrothermal treatment of commercial P25 TiO2 powder in 10 M NaOH at 200 degrees C for 20 h followed by soaking in 0.1 M HNO3 to perform ion exchange between the as-synthesized Na titanate and H. By controlling pH of the solution during hydrothermal treatment of the hydrogen titanate precursor, pure anatase TiO2 nanofiber was obtained. Its band-gap energy determined from the onset of diffused reflectance spectrum was 3.19 eV which is equal to that of anatase TiO2 powder. The TiO2 nanofiber showed higher photodecomposition efficiency than the Cotiox KA-100 TiO2 but lower than the P25 TiO2. Photodegradation is the predominant process for 'Reactive blue 171' removal.
...
PMID:Hydrothermal synthesis and photocatalytic activity of anatase TiO2 nanofiber. 2290 66

Metastable hexagonal MoO3 microrods were grown from bulk MoS2 and used as support materials for MoS2 and TiO2 nanoparticles. The hybrid composites that consisted of MoO3, MoS2, and TiO2 were prepared at a low temperature using the one-step synthesis method. The crystallinity and morphology of the MoO3/MoS2/TiO2 composites that were prepared using HNO3 and titanium tetraisopropoxide were compared with those of the MoO3/MoS2 composites that were prepared without titanium tetraisopropoxide. Titanium isopropoxide facilitated the formation of the MoO3 microrods from the oxidation of the bulk MoS2. The desired MoO3/MoS2/TiO2 composites were obtained using 0.5 g of bulk MoS2, 3-4 ml of HNO3, and 0.367 ml of titanium tetraisopropoxide. The MoO3/MoS2/TiO2 composites that were treated with ultrasonic waves showed rapid degradation of the methylene blue solution (2 x 10(-4) M) in the dark and good photocatalytic ability under ultraviolet light irradiation. The decomposition of methylene blue depended on the composition of the composite.
...
PMID:Preparation of MoO3/MoS2/TiO2 composites for catalytic degradation of methylene blue. 2296 75

As an important precursor of hydroxyl radical, nitrous acid (HONO) plays a key role in the chemistry of the lower atmosphere. Recent atmospheric measurements and model calculations show strong enhancement for HONO formation during daytime, while they are inconsistent with the known sources in the atmosphere, suggesting that current models are lacking important sources for HONO. In this article, heterogeneous photochemical reactions of nitric acid/nitrate anion and nitrogen oxide on various aerosols were reviewed and their potential contribution to HONO formation was also discussed. It is demonstrated that HONO can be formed by photochemical reaction on surfaces with deposited HNO3, by photocatalytic reaction of NO2 on TiO2 or TiO2-containing materials, and by photochemical reaction of NO2 on soot, humic acids or other photosensitized organic surfaces. Although significant uncertainties still exist in the exact mechanisms and the yield of HONO, these additional sources might explain daytime observations in the atmosphere.
...
PMID:Review of heterogeneous photochemical reactions of NOy on aerosol - A possible daytime source of nitrous acid (HONO) in the atmosphere. 2359 53


<< Previous 1 2 3 Next >>