Preparation of Novel Pt–BiVO4/Fly Ash Cenospheres Composites with High Photocatalytic Performance

A novel fly ash cenospheres supported Pt–BiVO4 composites (Pt–BiVO4/FACs) photocatalysts were prepared by modified metalorganic decomposition process, followed by photochemical reduction. The composites were characterized by X-ray diffraction (XRD), X-ray photoelectron spectra (XPS), and UV–vis diffused reflectance spectroscopy (DRS) techniques. The results indicate that the visible light absorption of the Pt–BiVO4/FACs composite is greatly enhanced. The Pt element is present in the metallic form and disperses in the composite samples. Photocatalytic activities of the Pt–BiVO4/FACs composites were evaluated by the methylene blue (MB) degradation under visible light irradiation. The results indicate that the photocatalytic efficiency is significantly improved after the Pt species was loaded and the 2 wt% Pt-loaded composite showed the highest photocatalytic activity.

Nucleation kinetics of SrTiO3 3D islands and nanorings on Si substrates

The nucleation of SrTiO3 three-dimensional (3D) islands and nanorings on Si substrates via a novel metalorganic decomposition (MOD) process has been investigated as a function of temperature and solution concentration of the SrTi(OC3H7)6 precursor.

Photocatalytic Degradation of Methyl Orange and Phenol by BiVO4-Loaded Fly Ash Cenospheres (FACs) Composite

A novel photocatalyst, BiVO4-loaded fly ash cenospheres (BFACs), was prepared by the modified metalorganic decomposition (MOD) method. Its physicochemical properties were characterized by X-ray diffractometry (XRD), Raman spectroscopy, scanning electron microscopy with energy dispersive X-ray microanalyses (SEM-EDX) and UV-vis diffused reflectance spectroscopy (DRS). The photocatalytic activities of the as-prepared sample were evaluated by the photodegradation methyl orange (MO) dye and phenol in aqueous solution under visible-light irradiation. It was found that the photocatalytic activity of BFACs composite for the degradation of MO and phenol were higher than that of pure BiVO4. Moreover, much enhanced photocatalytic performance for phenol degradation was also realized with the assistance of H2O2. The BFACs photocatalysts were stable and maintained high photocatalytic efficiency of MO during repeated recycles. The BFACs photocatalyst is promising for practical applications in purification of dye-containing wastewater.

Growth of epitaxial CeO2 buffer layers by polymer assisted deposition

ABSTRACTPolymer assisted deposition (PAD) has been reported as a novel CSD approach for thin film growth with improved homogeneity and long stability by forming a metal polymer species. It also offers the interesting possibility of having a library of PAD solutions for each precursor metal and obtaining the required composition by simple mixing. Another potential advantage is the increase in thickness since mechanical stresses are expected to be alleviated during shrinkage in the metalorganic decomposition by the metal-polymer network.Cerium oxide films on YSZ single crystals were grown from water-based solutions containing cerium nitrate, polyethyleneimine and complexing EDTA, in order to explore the benefits of using the PAD approach for growing buffer layers in coated conductors. An ultrafiltration step was performed to remove the non-coordinated species in solution. The degree of purification and efficiency in the cerium recovery was investigated by different techniques. TGA-DTA analysis was used to provide guidance to the best thermal profiles in different atmospheres and specially to diminish the adverse effects of exothermic events during decomposition. Microstructural evolution was tracked by AFM and TEM, while epitaxial fraction was followed by X-ray diffraction. The results show the high importance of choosing the proper atmosphere and the need for tuning of heating ramps to obtain dense, flat and epitaxial ceria films by PAD.

Growth and Electrical Properties of PbMg0.047Nb0.095Zr0.416Ti0.442O3 Films Fabricated by Metalorganic Decomposition

On the basis of experimental data on the piezoelectric pinpoint composition of ceramics of the ternary system Pb(Mg1/3Nb2/3)O3-PbZrO3-PbTiO3 (PMNZT), which we investigated in our previous report, epitaxial PbMg0.047Nb0.095Zr0.416Ti0.442O3 thick films with thicknesses ranging from 0.4 to 1.9 m were fabricated on Pt(100)/MgO(100) substrates by metalorganic decomposition. The film- thickness dependence on the structural and electrical properties (dielectric, piezoelectric and ferroelectric properties) was investigated. All PMNZT films exhibited a highly uniform (001) orientation, regardless of the film thickness. The cross-sectional transmission electron microscope micrographs and all the physical data suggest that high-density PMNZT thick films with a thickness  1.0 m can be expected to function as highly electrically insulating capacitors with high potential for piezo- and ferroelectric applications.