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Abstract: In this paper, we report the obtention of MnWO4 nanocrystals with different shapes, such as: nanospheres, nanorods, and urchin-like microspheres were synthesized by a surfactant-free hydrothermal method. The as-obtained powders were characterized by X-ray diffraction patterns and transmission electron microscopy. XRD patterns indicate that these crystals have a wolframite-type monoclinic structure without deleterious phases. The TEM images revealed that the pH values and precursors played a key role in the morphology-controlled synthesis of MnWO4 nanocrystals. This green method is an effective approach to the controlled growth of MnWO4 nanocrystals with different shapes, which are of interest for both theoretical investigations and practical applications. Finally, a possible growth mechanism for the formation of the MnWO4 microcrystals with different shapes was discussed in detail. [Copyright &y& Elsevier]

Abstract: PbWO4 dendrites have been successfully synthesized by a simple sonochemical method without any surfactants at room temperature. The as-prepared powders were characterized by X-ray powder diffraction (XRD), transmission electron microscopy (TEM), electron diffraction (ED), and high-resolution transmission electron microscopy (HRTEM). The effect of pH value, molar ratio of [WO4 2−]/[Pb2+], reaction time, and the initial concentration of the starting solution on the formation of PbWO4 dendrites was investigated. Experimental results indicate that the molar ratio of [WO4 2−]/[Pb2+] played a crucial role in the formation of PbWO4 dendrites. A growth mechanism of PbWO4 dendrites was also discussed. The present process is proved to be environment-friendly, and can be extended to the controllable synthesis of other tungstates. [Copyright &y& Elsevier]

Abstract: Cadmium tungstate (CdWO4) nanorods were successfully synthesized via a hydrothermal process and characterized by X-ray powder diffraction (XRD), transmission electron microscopy (TEM), and photoluminescent spectra techniques (PL). A pure monoclinic phase of well-crystallized CdWO4 nanorods, with lengths of 250–400nm and widths of 30–60nm, could be readily synthesized at as low temperature as 70°C.The CdWO4 nanorods showed a PL emissions peak at 435nm. [Copyright &y& Elsevier]

Abstract: Na0.5Bi0.5TiO3 microcubes with smooth faces and clear, well-defined edges have been successfully prepared for the first time by a simple hydrothermal method without any surfactants. The as-prepared Na0.5Bi0.5TiO3 microcubes showed an obvious emission band compared with nanoparticles, which is attributed to the different NBT morphology and size. [Copyright &y& Elsevier]

Abstract: Bi2Fe4O9 (BFO) nanoparticles were successfully synthesized by a hydrothermal method at a temperature as low as 100°C. The as-prepared powders, characterized by X-ray diffraction (XRD), energy dispersive spectroscopy (EDS), transmission electron microscope (TEM) and physical property measurement system (PPMS), exhibited a pure BFO phase about 100nm size with uniform sheet-like shape and exhibited an AF order at room temperature. It was found that high alkali concentration and alkali ion Na+ played a key role in the formation of BFO nanoparticles at a low temperature of 100°C. [Copyright &y& Elsevier]

Abstract: CaMoO4 nanoparticles were successfully synthesized by a molten salt method at a temperature as low as 270°C. The as-prepared powders, characterized by X-ray diffraction (XRD) and transmission electron microscopy (TEM), exhibited a pure CaMoO4 phase about 70nm in particle size and uniform nearly-spherical particle shape. The room temperature luminescent spectra were performed on a Fluorolog-3 spectrofluorometer; the powders exhibited green emission peaks of 508nm. The molten salt medium could speed up the diffusion rates of the reaction ions, and thus decrease greatly the synthesis temperature of CaMoO4 nanoparticles. [Copyright &y& Elsevier]

Abstract: Er3+ doped yttrium lanthanum oxide transparent ceramics were fabricated by the conventional ceramics processing and their luminescence properties were investigated. The ceramics displayed high transparency and uniform grains without pores. Under the excitation of 980nm laser diode, intense green and red up-conversion luminescences were observed due to 2H11/2/4S3/2→4I15/2 and 4F9/2→4I15/2 transitions of Er3+ ions, respectively. 2at% Er3+:(Y0.9La0.1)2O3 ceramics had longer fluorescence lifetime and the emission cross-sections (σ em) at 1536nm was calculated to be 5.87×10−21 cm−2, while it was 6.83×10−21 cm−2 for 1at% Er3+:(Y0.9La0.1)2O3 ceramics. [Copyright &y& Elsevier]

Abstract: Nano-sized (Sn0.25,Ti0.75)O2 photocatalysts were successfully synthesized by a molten salt (MS) method at 260°C for 2h, where a homogeneous precipitate containing titanium and tin cations as a precursor. The synthesized powders were investigated by X-ray diffraction (XRD), transmission electron microscopy (TEM) and UV–vis, respectively. The results show that the products are composed of homogeneously spherical particles with an average size of ca.10nm, and have better UV absorption and visible light response when the reaction temperature is increased to 400°C. [Copyright &y& Elsevier]