Tungsten Oxide
Mostrando 1-12 de 24 artigos, teses e dissertações.
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1. Hydrogen Peroxide Electrogeneration by Gas Diffusion Electrode Modified With Tungsten Oxide Nanoparticles for Degradation of Orange II and Sunset Yellow FCF Azo Dyes
In this work, the gas diffusion electrode (GDE) cathode of Vulcan XC72 carbon modified with nanoparticles of WO2.72 (WO2.72 / Vulcan XC72) was used for H2O2 electrogeneration and degradation of 350 mL of Orange II (OII) and Sunset Yellow FCF (SY) azo dyes by electro-Fenton (EF) and photoelectro-Fenton (PEF) processes with different Fe2+ initial content (1.00
J. Braz. Chem. Soc.. Publicado em: 16/09/2019
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2. Insights on Structuration of Peroxotungstic Acid in Aqueous Media
Recent studies on tungsten oxide preparation are mainly motivated by its applications in smart windows, energy harvesting and, recently, in cancer therapy. Peroxotungstic acid (PTA) is an important precursor to obtain tungsten oxide in an environmentally-friendly way, through the colloidal synthesis in aqueous media. Despite giving chemically pure products,
J. Braz. Chem. Soc.. Publicado em: 2019-04
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3. Theoretical Approach to Simulate Efficient Selective Solar Absorbers With Micro or Nano Structured Arrays
Study of the solar absorber with photonic crystal or micro structures as the heat absorbing surfaces operated at a high-temperature was conducted. Numerical calculations based on rigorous coupled-wave analysis were performed to determine the absorptance of the photonic crystal surface on the absorber. The effect of nano geometry of the photonic crystal in tu
Mat. Res.. Publicado em: 22/03/2018
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4. Plasma-spray synthesis and characterization of ti-based nitride and oxide nanogranules
The synthesis of nanosized Ti-based nanogranules via plasma spraying is reported. The synthesis route involved use of both nitrogen and oxygen gases with varying results. In the case of nitrogen, a mixture of titanium nitrides were produced, yielding both the Ti2N and the sub-stoichiometric TiN0.61 compounds. In the case of oxygen, both the stoichiometric ru
Mat. Res.. Publicado em: 15/08/2014
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5. The Risk Evaluation of Tungsten Oxide Nanoparticles in Cultured Rat Liver Cells for Its Safe Applications in Nanotechnology
Tungsten (VI) oxide (WO3) nanoparticles (NPs) are used for many industrial purposes in everyday life. However, their effects on human health have not been sufficiently evaluated. Therefore, the present study was designed to investigate the toxicity potentials of various concentrations (0 to 1000 ppm) of WO3NPs (<100 nm particle size) in cultured primary rat
Braz. arch. biol. technol.. Publicado em: 2014-08
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6. Tungsten oxide thin films grown by thermal evaporation with high resistance to leaching
Óxidos de tungstênio apresentam diferentes estequiometrias, estruturas cristalinas e morfologias. Estas características são importantes principalmente quando se deseja utilizá-los como fotocatalisadores. Neste trabalho foram obtidos filmes finos de óxido de tungstênio por evaporação térmica sobre substratos de silício (100) recobertos com ouro, aq
J. Braz. Chem. Soc.. Publicado em: 2014-05
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7. Effect of tungsten doping on catalytic properties of niobium oxide
Um novo material à base de nióbia (Nb2O5) foi sintetizado e quimicamente modificado para oxidar compostos orgânicos em meio aquoso, na presença de H2O2. A nióbia foi modificada por dopagem com tungstênio e também tratamento com H2O2 com o intuito de potencializar suas propriedades oxidativas. A investigação dos produtos gerados pela oxidação do az
Journal of the Brazilian Chemical Society. Publicado em: 2012-04
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8. Síntese, caracterização e estudos das propriedades catalíticas de compostos formados por óxido de tungstênio e pentóxido de vanádio / Synthesis, Characterization and Study of Catalytic Properties of Compounds Formed by Tungsten Oxide and Vanadium Oxide.
Métodos de síntese que viabilizam a obtenção de compósitos contendo xerogéis de óxido de tungstênio e de pentóxido de vanádio pelo método sol-gel foram investigados, bem como a caracterização e propriedades catalíticas nas reações de epoxidação destes materiais. Brometo de cetiltrimetilamina e hexadecilamina foram intercalados nos xerogéis
IBICT - Instituto Brasileiro de Informação em Ciência e Tecnologia. Publicado em: 11/11/2011
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9. Efeito de metais de transição sobre a polarização espontânea na estrutura cristalina de nanopós da família tungstênio bronze
This work aimed the study of the effect of transition metals (Ni, Fe, Co) on the spontaneous polarization of the ferroelectric oxides of tetragonal tungsten bronze (TTB)-type structure of potassium strontium niobate (KSr2Nb5O15) and of the KSr2(FeNb4)O15-d, KSr2(NiNb4)O15-d and KSr2(CoNb4)O15-d solid solutions. All systems investigated were prepared by mecha
IBICT - Instituto Brasileiro de Informação em Ciência e Tecnologia. Publicado em: 28/02/2011
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10. Análise por componentes principais de espectros nexafs na especiação do molibdênio em catalisadores de hidrotratamento
Bulk and supported molybdenum based catalysts, modified by nickel, phosphorous or tungsten were studied by NEXAFS spectroscopy at the Mo L III and L II edges. The techniques of principal component analysis (PCA) together with a linear combination analysis (LCA) allowed the detection and quantification of molybdenum atoms in two different coordination states
Química Nova. Publicado em: 2010
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11. Construção de célula eletroquímica para observação de amostras in situ em estereomicroscópio
The electrochemical study of glass like tungsten oxide derivatives requires the construction of special electrodes due to the fact that these glasses are not conductive. Electrodes modified with WO3 change their color when submitted to some potential perturbation. The color change of the electrochromic materials was observed in situ by coupling an electroche
Química Nova. Publicado em: 2010
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12. Sintese de materiais nanoestruturados MS IND. 2 (M = Mo, W) com alta pureza de fase e morfologia / Synthesis of MS IND. 2 (M = Mo, W) nanostructured materials with high purity of phase and morphology
The main of this Dissertation is the preparation of nanostructured WS2 and MoS2 from a template reaction with the respective nanorods oxides. Molybdenum oxide nanorods with diameters around 100 nm and microscale lengths were prepared from MoO3·2H2O via a one step solvothermal reaction. The formation of MoO3 rods proceeds in acidic media at 180 °C. The oxid
Publicado em: 2008