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The synthesis and photoluminescence (PL) properties of aqueous CdTe/ZnO core/shell quantum dots (QDs) have been investigated by using thiolglycolic acid as a capping reagent. The highlighted contribution of the present study was CdTe QDs coated with a ZnO shell by controlling the hydrolysis process of Zn(OAc). The QDs benefitted from overcoming the high lattice mismatch between CdTe and ZnO. The PL peak wavelength of the CdTe/ZnO QDs with high PL quantum yields up to 88% was located in a range between 547 and 596 nm by adjusting the size of CdTe cores and the thickness of ZnO shells. The results of X-ray diffraction analysis and transmission electron microscopy observation indicate that the dot-shaped CdTe/ZnO QDs (566 nm) with an average size of 2.2 nm in diameter belong to the cubic CdTe crystal structure. Due to the passivation of surface defects, it is found that the luminescence decay curves accord with a biexponential decay model of exciton and trap radiation behavior. The average PL lifetimes of CdTe (571 nm) and CdTe/ZnO (596 nm) QDs at room temperature are 27.3 and 35.1 ns, respectively. [ABSTRACT FROM AUTHOR]

Abstract: Eu3+-doped SrZrO3 nanocrystals with a size of about 10nm were synthesized by a simple sol–gel combustion method, and characterized by X-ray diffraction, transmission electron microscopy and photoluminescence spectroscopy. The nanocrystalline intend to assemble to a porous morphology. Both intrinsic defects related and activator luminescence were observed. The red emission of Eu3+ is intense and the spectra show a minor difference with different excitation wavelengths. [Copyright &y& Elsevier]

Abstract: The oxidation behaviour of nanometre and micrometre sized Al2O3–TiC–Co composites is investigated at 800–1000°C in air for 25h. The oxidation resistance of nanometre sized samples is better than of micrometre sized. Phase compositions and microstructures were studied by XRD and SEM. The values of general rate constant k and oxidation exponent n are dependent on oxidation temperature and composites. The oxidation kinetics followed a rate that is slightly faster than the parabolic-rate law at 800–1000°C. The activation energy of the nanometre sized is higher than of micrometre sized in the range of 800–1000°C. [Copyright &y& Elsevier]

Abstract: The oxidation behavior of nano-sized Al2O3–TiC–Co composite sintered at different temperature was investigated at 200–1000°C in air for 25h. Microstructures and phase compositions of oxidation surfaces were studied by X-ray diffraction (XRD) and scanning electron microscopy (SEM). Results indicated that the oxidation reaction would take place when oxidation temperatures are 800°C and 1000°C. The oxidation resistance of Al2O3–TiC–Co composite increased with the sintering temperature rising when the sample was oxidized at 800°C and 1000°C. The mechanism of oxidation has been analyzed using thermodynamic and kinetics considerations. The oxidation kinetics follows a rate that is faster than the parabolic rate law at 800°C and 1000°C. The activation energy of the composite for oxidation in the range of 800°C to 1000°C was found to be 142.21kJ/mol. [Copyright &y& Elsevier]

Abstract: Bi4Ti3O12 thin films with bismuth-layered perovskite structure have been successfully fabricated by means of chemical solution decomposition (CSD) and characterized by X-ray diffraction (XRD), atomic force microscopy (AFM), scanning electron microscopy (SEM) and UV–vis spectrophotometry in this study. The photocatalytic activity of Bi4Ti3O12 thin films has been evaluated by photodegrading methyl orange solution, and the optimum processing parameters for the photocatalytic activity have been found. Moreover, it has been found that La-doping can improve the photocatalytic activity of Bi4Ti3O12 thin films and hinder the increase of crystallite sizes during calcination. [Copyright &y& Elsevier]

Abstract: Nb2O5 nanorods have been prepared using water/ethanol media. The samples were characterized by X-ray diffraction (XRD), transmission electron microscopy (TEM), UV–visible absorption and photoluminescence spectroscopy. The as-prepared Nb2O5 nanorods appeared to be single pseudohexagonal (TT-Nb2O5) phase. From the photoluminescence spectrum, two emission bands at 407 and 496nm, respectively, were observed. The origin of the luminescence was discussed in detail. [Copyright &y& Elsevier]

Abstract: Pure and Dy3+-doped Zn2SnO4 (ZTO) hollow spheres, integrated with nanoparticles, have been synthesized using the coprecipitation method. The ZTO spheres have been characterized with X-ray diffraction and scanning electron microscope. The photoluminescence and photocatalytic properties are investigated. The influences of Dy3+ ions on the morphology and the photoluminescence of ZTO have been explained in detail. [Copyright &y& Elsevier]