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Abstract: ZnIn2S4 nanopowder was synthesized via a facile hydrothermal method using Zn(CH3COO)2·2H2O, InCl3·4H2O and thioacetamide as the reactants, and characterized by X-ray diffraction, transmission electron microscopy, N2 adsorption and UV–Vis diffuse reflectance spectrum. The photocatalytic property of the as-synthesized ZnIn2S4 nanopowder was tested for the first time by the reduction of aqueous Cr(VI) under visible light (λ>420nm) irradiation, and compared with those of In2S3, ZnS and P25 TiO2. It was found that the as-synthesized ZnIn2S4 nanopowder was much more efficient than In2S3, ZnS and P25 TiO2 in the photocatalytic reduction of aqueous Cr(VI). Moreover, X-ray photoelectron spectroscopy analysis revealed that Cr(VI) was reduced to Cr(III) by ZnIn2S4-mediated photocatalysis. [Copyright &y& Elsevier]

Abstract: Submicron-sized SrTiO3 crystallites were prepared by a low temperature solid state method. The proposed preparation method involved two simple steps: firstly, SrO2 nanoparticles of 35–90 nm were precipitated from the reaction of Sr(NO3)2 and H2O2 in an alkalescent aqueous solution (pH=8) under the ambient condition; secondly, perovskite phase SrTiO3 with a minor amount of SrCO3 impurity were produced by heating the mixture of excessive SrO2 nanoparticles and commercial TiO2 powders in air at 700 °C for 10 h, which could be easily washed with 1 mol/l HNO3 aqueous solution and distilled water to yield pure SrTiO3 crystallites with the size of about 125–320 nm. The phase, purity and size of the as-obtained product were characterized by means of powder X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), and field emission scanning electron microscopy (FESEM). [Copyright &y& Elsevier]

Abstract: Without the use of any extra surfactant or template, hexagonal phase ZnO crystallites consisting of individual nanorods or nanorod assemblies were synthesized simply by solvothermal treatment of several nanometer ZnO2 nanoparticles in three different solvents (including ethanol, 80 wt.% hydrazine hydrate aqueous solution and ethylenediamine) at 150 °C for 24 h. The structures and optical properties of the resultant products were characterized by means of X-ray powder diffraction (XRD), scanning electron microscope (SEM), and room temperature photoluminescence (RTPL) spectra. The RTPL spectra of the resultant products all showed a much stronger ultraviolet bandgap emission peaking at around 387 nm and a weaker emission associated with the defect level. The as-synthesized ZnO crystallites are promising materials for the optoelectronic devices due to their excellent UV emission properties. [Copyright &y& Elsevier]

Abstract: ZnO2 hollow nanospheres and nanotubes were synthesized via hydrothermal treatment of ZnO submicron-sized powder in 20vol.% H2O2 aqueous solution at 120°C for 6h, and ZnO with similar hollow nanostructures could be obtained by thermal decomposition of the hydrothermally-synthesized ZnO2 hollow nanospheres and nanotubes in air at 200°C for 6h. The possible formation mechanisms of the ZnO2 and ZnO hollow nanostructures were proposed. The present work pointed out a simple, cost-effective and green way of converting bulk ZnO powder into hollow-nanostructured ZnO2 and ZnO powders. The as-synthesized hollow-nanostructured ZnO2 and ZnO powders have promising uses as catalysts, adsorbents and light weight fillers, etc. [Copyright &y& Elsevier]

Abstract: An alternative low cost method was proposed for the low temperature (600°C) preparation of CdTiO3 nanoplates, using low-melting-point Cd(NO3)2 ·4H2O and high-reactive-activity TiO2 nanocrystals as the reactants. The structure, composition, specific surface area, thermal stability and optical properties of the as-synthesized products were characterized by X-ray diffraction, energy dispersive X-ray spectroscopy, field emission scanning electron microscopy, Brunauer–Emmett–Teller surface area analysis, UV–vis absorption and room temperature photoluminescence spectra. The as-synthesized CdTiO3 nanoplates were thermally stable at temperatures ≤900°C, and their phase changed from ilmenite to perovskite when heated in air at 1000°C for 2h. Besides, they exhibited a strong and broad visible light emission in the range of about 470–750nm upon laser excitation at 325nm, enabling their use as a luminescent material. [Copyright &y& Elsevier]

Abstract: Choosing low-melting-point Ca(NO3)2·4H2O and high-reactive-activity TiO2 nanocrystals as the raw materials, a simple and cost-effective route was developed for the synthesis of CaTiO3 nanoparticles at 600°C, which is much lower than that (about 1350°C) used in the conventional solid state reaction methods. X-ray diffraction, energy dispersive X-ray spectroscopy and field emission scanning electron microscopy revealed the formation of orthorhombic phase CaTiO3 nanoparticles with oxygen-deficiency at the surface. UV–vis absorption spectrum of the as-obtained CaTiO3 nanoparticles displayed an absorption peak centered at around 325nm (3.8eV), together with a tail at lower energy side. Room temperature photoluminescence spectrum of the as-obtained CaTiO3 nanoparticles upon laser excitation at 325nm demonstrated a strong and broad visible light emission ranging from about 527 to 568nm, which may be originated from the surface states and defect levels. [Copyright &y& Elsevier]

Abstract: A green method based on the reaction between hydrozincite (Zn5(CO3)2(OH)6) powder and hydrogen peroxide (H2O2, 30wt.%) in aqueous solution at room temperature was developed for the synthesis of ZnO2 nanoparticles. Results from X-ray diffraction, transmission electron microscopy and Raman demonstrated that the resultant products were pure cubic phase ZnO2 nanoparticles, whose sizes were in the range of 3.1–4.2nm. Thermogravimetric analysis indicated that between 180 and 350°C, the as-synthesized ZnO2 nanoparticles had a weight loss of about 16.7%, consistent with the theoretical amount (16.4%) of the O2 released from ZnO2 decomposition (ZnO2 =ZnO+1/2O2). The present method was green, simple and cost-effective, which should be suitable for large-scale production of multifunctional ZnO2 nanoparticles. [Copyright &y& Elsevier]