Photoelectron Diffraction
Mostrando 1-12 de 69 artigos, teses e dissertações.
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1. Catalysts Derived from Thermal Treatments of Hydrocalumite-Type Compounds: Synthesis and Application in Transesterification Reactions
Catalyst performance is a relevant factor in biodiesel production because it can affect the efficiency of the process. This work provides a study of the performance of heterogeneous catalysts for biodiesel production derived from thermal-treated hydrocalumite-type compounds. This work aimed to synthesize and characterize hydrocalumite-type compounds intercal
Journal of the Brazilian Chemical Society. Publicado em: 2023
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2. Preparation and performance of magnetic zirconium-iron oxide nanoparticles loaded on palygorskite in the adsorption of phosphate from water
Magnetic zirconium-iron oxide nanoparticles loaded on palygorskite as a low-cost adsorbent was produced by one-step co precipitation technique and its properties for phosphate adsorption were overall investigated. The Brunauer Emmett Teller (BET) specific surface area analysis, scanning electron microscopy (SEM), thermo gravimetric analysis (TGA), Fourier tr
Química Nova. Publicado em: 2022
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3. Iron Cobaltite (FeCo2O4) Nanocatalysts for Water-Oxidation: Effects of Annealing Temperature on Catalytic Properties
The development of efficient, stable, and non-precious metal water oxidation catalysts (WOCs) is a matter of importance for sustainable energy research. In this work, iron cobaltite (FeCo2O4) nanoparticles were prepared by the coprecipitation method, and we present the effect of heat treatment (250, 350, 450, 650 and 900 °C) on the catalytic properties. Cat
Journal of the Brazilian Chemical Society. Publicado em: 2022
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4. Study of Crystallization and Composition on Silicon Oxycarbide (SiOC) and Silicon Boron Oxycarbide (SiBOC) Ceramics Obtained from Alkoxysilanes Precursors
This work deals on the preparation of silicon oxycarbide (SiOC) and silicon boron oxycarbide (SiBOC) ceramics from pyrolysis involving alkoxysilanes with different organic groups. Boron content, organic substituent and annealing time were evaluated on crystallization and composition of resulting ceramics. B-free precursors composed of methyltriethoxysilane (
J. Braz. Chem. Soc.. Publicado em: 2021-06
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5. Reusable Heterogeneous SnO2/ZnO Catalyst for Biodiesel Production from Acidified/Acid Oils
A catalyst comprised of SnO2 impregnated on ZnO nanowires, which presented remarkable ability to catalyze fatty acid esterification/transesterification reactions, is reported. For optimization of reaction conditions, artificially acidified soybean oil with 10 wt.% oleic acid was used as a model feed. The optimized conditions were: 150 °C, 6 h, 5 g of oil, c
J. Braz. Chem. Soc.. Publicado em: 2021-01
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6. Synthesis of ZnO Nanoparticles by the Sol-Gel Protein Route: A Viable and Efficient Method for Photocatalytic Degradation of Methylene Blue and Ibuprofen
The photocatalytic degradation of methylene blue dye and ibuprofen drug was studied in the presence of zinc oxide, synthetized by the protein sol-gel route. The catalyst, calcined at 1000 ºC, presented a tendentious morphology to filaments characteristic of ZnO crystalline, characterized by X-ray diffraction (XRD) and confirmed by the presence of Zn energy
J. Braz. Chem. Soc.. Publicado em: 2020-08
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7. Synthesis, Characterization, and Synergic Photocatalytic Activity of Amorphous TiO2/Chitosan Carbon Microspheres
In this work, we report the synthesis and characterization of new amorphous graphene-like TiO2/chitosan carbon microspheres and its performance as photocatalyst. Four different carbon chitosan microspheres materials were obtained based on the distinctive procedure to incorporate TiO2 and TiOSO4 to chitosan structure by pyrolysis at 600 °C. Detailed characte
J. Braz. Chem. Soc.. Publicado em: 2020-06
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8. Synthesis, Characterization and Photocatalytic Activity of Au/SiO2@TiO2 Core-Shell Microspheres
By using HAuCl4 as the gold precursor, spherical Au@SiO2/TiO2 core-shell nanostructures were prepared with the sol-gel method and ethanol reflux. The preparation process was convenient and fast. The obtained samples were characterized by UV-Vis, X-ray diffraction (XRD), field emission scanning electron microscopy (FESEM), transmission electron microscopy (TE
J. Braz. Chem. Soc.. Publicado em: 2020-03
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9. Solvothermal Synthesis of Cerium-Doped Titania Nanostructured Materials Modified with Acetylacetone for Solar-Driven Photocatalysis
This study reports the preparation of nanostructured cerium-doped titanium dioxide photocatalysts containing different cerium concentrations by a modified sol-gel route involving the use of acetylacetone. The nanocrystalline powders had their structural, morphological, and optical properties characterized by X-ray diffraction, vibrational and Raman spectrosc
J. Braz. Chem. Soc.. Publicado em: 2020-01
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10. Hydrogen production from aqueous glycerol using titanate nanotubes decorated with Au nanoparticles as photocatalysts
Abstract: Protonated titanate nanotubes (HTiNts) were synthesized using the hydrothermal method, followed by proton exchange with acid. Gold nanoparticles decorated titanate nanotubes (AuHTiNts) were obtained by the reduction of AuCl4- under vigorous stirring with an aqueous solution of HTiNts containing 1 wt% of ascorbic acid. To investigate the surface str
An. Acad. Bras. Ciênc.. Publicado em: 28/11/2019
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11. Green synthesis and Characterization of ZnO-CoFe2O4 Semiconductor Photocatalysts Prepared Using Rambutan (Nephelium lappaceum L.) Peel Extract
In this work, the semiconductor of ZnO-CoFe2O4 composites were prepared by green synthesis approach using rambutan peel extract (Nephelium lappaceum L.) as a capping agent. X-ray diffraction patterns of composites showed the main peaks of ZnO at 2θ = 31.8°, 34.5°, and 36.2° corresponding to hexagonal wurtzite structure and weak peak at 2θ = 35.4° for c
Mat. Res.. Publicado em: 30/09/2019
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12. Characterization of Ti-35Nb alloy surface modified by controlled chemical oxidation for surgical implant applications
ABSTRACT Titanium-Niobium alloys have been studied for biomedical applications due to their satisfactory biocompatibility. In order to improve the long-term implantation, surface modification techniques have been developed to generate suitable topography, roughness, chemical composition, surface energy, etc. Considering this approach, the present work aimed
Matéria (Rio J.). Publicado em: 16/09/2019