Photoactivity
Mostrando 1-12 de 20 artigos, teses e dissertações.
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1. Evaluation of the Photocatalytic Potential of TiO2 and ZnO Obtained by Different Wet Chemical Methods
This paper describes the development of TiO2 and ZnO particles by a chemical route, using two different wet synthesis methods: polymeric precursor (PP) and sol-gel (SG). This study aimed to shed a light on how the synthesis method affects the photocatalytic activity of these oxides. Rhodamine B (RhB) degradation was used as a probe reaction to test the as-sy
Mat. Res.. Publicado em: 26/06/2017
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2. N and F Codoped TiO2 Thin Films on Stainless Steel for Photoelectrocatalytic Removal of Cyanide Ions in Aqueous Solutions
N-F codoped TiO2 films were immobilized on stainless steel sheets through a combined approach involving a dip-coating technique and a hydrothermal treatment, followed by calcination at 400°C in the presence of air. Photocatalyst characterization was conducted using XRD, Raman and UV-VIS spectroscopy as well as SEM. The films were tested in a three-electrode
Mat. Res.. Publicado em: 23/02/2017
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3. COMPARATIVE STUDY OF THE PHYSICOCHEMICAL PROPERTIES AND PHOTOCATALYTIC ACTIVITY OF MODIFIED MCM-41 SYNTHESIZED BY DIRECT (ONE-STEP) INCORPORATION AND IMPREGNATION
MCM-41 structures were synthesized and modified by direct (one-step) incorporation (DI) and wet impregnation (WI) methods. The solids were characterized by XRF, XRD, N2 adsorption and UV-Vis DR, and catalytically evaluated in the Acid Orange 7 (AO7) degradation under visible light. Significant influence of the presence, dispersion and location of the differe
Quím. Nova. Publicado em: 2016-06
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4. Use of Natural Rubber Membranes as Support for Powder TiO2and Ag/TiO2 Photocatalysts
The purpose of this study was to synthesize TiO2-polymer composites able to act as photocatalyst membranes. TiO2 catalysts were prepared using the sol-gel method to contain 0.0, 0.5, 1.0, and 2.0 wt.% of embedded Ag particles, subsequently incorporated into natural rubber latex at a weight fraction of 15%. Samples of these ceramic powders were suspended in a
J. Braz. Chem. Soc.. Publicado em: 2016-03
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5. Low Temperature Synthesis of Mixed Phase Titania Nanoparticles with High Yield, its Mechanism and Enhanced Photoactivity
A novel process was developed for the synthesis of a mixed phase (constituted of 66% anatase phase) of TiO2 nanoparticles at lower calcination temperature (400 oC) by the sol gel technique using a cost effective and easily available propanol solvent. Stereochemistry of propanol played a crucial role towards crystallographic phase of resultant TiO2nanoparticl
Mat. Res.. Publicado em: 26/02/2016
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6. Synthesis and Characterization of Mesoporous Nb2O5 and Its Application for Photocatalytic Degradation of the Herbicide Methylviologen
This article reports the characterization of mesoporous Nb2O5 synthesized by the sol-gel method for application in photocatalysis. The emerging contaminant methylviologen was employed for photocatalytic tests. Parameters inherent to the synthesis process, such as stirring rate, aging temperature, and calcination temperature, were employed for a range of valu
J. Braz. Chem. Soc.. Publicado em: 2016-02
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7. Efeito fotoiniciador sobre propriedades físicas, mecânicas e térmicas de compósitos experimentais fotoativados por luz de lâmpada halógena e LEDs / Effect of the photo-initiator on physical, mechanics and thermal properties of experimental composites photo-activated for halogen lamp and LEDs
The aim of this study was to analyze the spectrum of different lightcuring units (LCUs) and photo-initiators and yours influence in the physical and thermal properties and bond strength (BS) of experimental resin composites with different photo-initiators. A blend with BisGMA, UDMA, BisEMA, TEGDMA and 65 wt% of silanated filler particles was prepared with CQ
IBICT - Instituto Brasileiro de Informação em Ciência e Tecnologia. Publicado em: 05/08/2010
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8. Propriedades morfológicas e estruturais e rendimento quântico de geração de radicais hidroxila em amostras sintetizadas de dióxido de titânio
No presente trabalho foram empregadas três diferentes metodologias de síntese (sol-gel, macroemulsão, precipitação do dióxido de titânio (TiO2), a partir da hidrólise do tetraisopropóxido de titânio solvatado por diferentes monoalcoóis), para a obtenção de nanomateriais fotoativos baseados TiO2. As diferentes amostras obtidas foram caracterizada
Publicado em: 2010
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9. Obtenção e caracterização de materiais catalisadores da oxidação de contaminantes em solução aquosa
"Sn" and "Al" materials, with different reasons in Sn/Al2O3 mass were obtained, characterized and tested as catalysts for the oxidation of indigo carmine dye. The characterization of the materials confirmed the presence of Sn (IV) in all samples. It was observed only one phase, the SnO2. The particle size obtained was 22 to 36 nm. The photocatalytic tests sh
Publicado em: 2010
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10. Preparação e caracterização de eletrodos de titanatos para aplicação em conversão de energia solar / Preparation and characterization of titanate electrodes for solar energy conversion
Thin porous films electrodes of titanates H2Ti2O5, H2Ti4O9 and H2Ti8O17 were prepared and investigated. The titanates were synthesized through solid state reactions by heating mixtures of TiO2 and K2CO3; after HCl treatment for ion exchange, the samples were rinsed with water. X-ray diffraction and scanning electron microscopy indicated that, depending on th
Publicado em: 2009
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11. Síntese, caracterização e fotoatividade de fotossensibilizadores derivados de protoporfirina IX e de clorofilina / Synthesis, characterization and photoactivity of photosensitizers derivatived from protoporphyrin IX and chlorophyllin
Processos que envolvem sensibilização são extremamente importantes para diversas áreas do conhecimento, incluindo a biologia, a química e a medicina. A aplicação de sensibilização em medicina tem se destacado, especialmente, em face de uma modalidade alternativa de tratamento de câncer denominada terapia fotodinâmica (TFD). Uma das linhas de pesqu
Publicado em: 2007
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12. Estudo das propriedades eletro- e fotoeletroquimicas do composito TiO2/PPi
Great advances were reached in the last three decades in the development of materials which bring together properties that are of interest in technological applications. The conducting polymers, since their discovery in 1977, were extensively studied in order to be used, e.g., in battery and electrochromic devices. Nowadays, the reseach about this matter is
Publicado em: 2002