A methodology to investigate the wear of blast furnace hearth carbon refractory lining

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Rapid preparation of alpha-FeOOH and alpha-Fe2O3 nanostructures by microwave heating and their application in electrochemical sensors

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

TiO2 synthesized by microwave assisted solvothermal method: Experimental and theoretical evaluation

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Microwave-assisted hydrothermal synthesis of magnetite nanoparticles with potential use as anode in lithium ion batteries

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Rapid calcination of ferrite Ni0.75Zn0.25Fe2O4 by microwave energy

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Titanate nanotubes produced from microwave-assisted hydrothermal synthesis: Photocatalytic and structural properties

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Determination of lead in eye shadow and blush by high-resolution continuum source graphite furnace atomic absorption spectrometry employing directSolid sampling

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Experimental and theoretical studies of photoluminescence in Zns obtained by microwave-assisted solvothermal method

A shift of the photoluminescence (PL) emission was observed in ZnS prepared by microwave assisted solvothermal method with the increase of the time in microwave. In this work we reported a study of the optical behavior linking with the structural disorder according to XRD and FEG-TEM results. The reduction of intrinsic defects in the lattice is responsible for the decrease of electronic levels in the band gap changing the PL profile. This effect was confirmed by electronic structure calculations.

Ce0.97Cu0.03O2 Nanocatalysts Synthesized via Microwave-assisted Hydrothermal Method: Characterization and CO-PROX Catalytic Efficiency

In the work presented here, Ce0.97Cu0.03O2 nanoparticles were synthesized by a microwave-assisted hydrothermal method under different synthesis temperatures. The obtained nanoparticles were tested as catalysts in preferential oxidation of CO to obtain CO-free H2 (PROX reaction). The samples were characterized by X-ray diffraction, transmission electron microscopy (TEM), electron paramagnetic resonance spectroscopy (EPR) and temperature-programmed reduction (TPR). X-ray diffraction measurements detected the presence of pure cubic CeO2 for all synthesized samples. TEM images of the Ce0.97Cu0.03O2 nanoparticles revealed that samples synthesized at 80°C are composed mainly of nanospheres with an average size of 20 nm. The formation of some nanorods with an average diameter of 8 nm and 40 nm in length, and the size reduction of the nanoparticles from 20 to approximately 15 nm is observed with increasing synthesis temperature. EPR spectra indicated that copper is found well dispersed in sample synthesized at 160°C, located predominant in surface sites of ceria. For samples synthesized at 80 and 120°C, the species are less dispersed than in the other one, resulting in the formation of Cu2+−Cu2+ dimmers at the surface of ceria. TPR profiles presented two reduction peaks, one below 400°C attributed to the reduction of different copper species and a second peak around 800°C attributed to the reduction of Ce4+→ Ce3+ species located in the volume of the nanoparticles. The peak related to the reduction of copper species shifts to lower temperatures with increasing synthesis temperature, i.e., the sample synthesized at 160°C is more easily reduced than the ones synthesized at 120 and 80°C. The nanoparticles showed active as catalysts for the CO-PROX reaction. The microwave-assisted method revealed efficient for the synthesis of Ce0.97Cu0.03O2 nanoparticles with copper species selective for the CO-PROX reaction, which reaches CO conversions up to 92% for the sample synthesized at 160°C.

Long-range and short-range structures of cube-like shape SrTiO3 powders: microwave-assisted hydrothermal synthesis and photocatalytic activity

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

SnO2 dense ceramic microwave sintered with low resistivity

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Microwave-assisted hydrothermal synthesis of NiO-Ce1-XEuxO2-δ powders for fuel cell catalytic anodes

CeO2-based materials doped with rare earth (TR +3) can be used as alternative to traditional NiO-YSZ anodes in solid oxide fuel cells as they have higher ionic conductivity and lower ohmic losses compared to YSZ. Moreover, they allow fuel cell operation at lower temperatures (500-800°C). In the anode composition, the concentration of NiO acting as catalyst in YSZ provides high electrical conductivity and high electrochemical activity of reactions, promoting internal reform in the cell. In this work, NiO - Ce1-xEuxO2-δ compounds (x = 0.1, 0.2 and 0.3) have been synthesized by microwave-assisted hydrothermal method. The materials were characterized by TG, XRD, TPR and SEM-FEG techniques. The refinement of data obtained by X-ray diffraction showed the presence of ceria doped with europium crystallized in a cubic phase with fluorite structure, in addition to the presence of NiO. The microwave-assisted hydrothermal method showed significant reduction in the average particle size and good mass control of phase compositions compared to other chemical synthesis techniques.

Simultaneous determination of chromium and nickel in medicinal plants by slurry sampling graphite furnace atomic absorption spectrometry

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Ethyl biodiesel: Microwave irradiation aiding ethanolysis of waste cooking oil.

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)