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We report on the synthesis of ultrathin SmVO4nanosheets through a simple and facile ionic liquid-assisted hydrothermal approach and their application in luminescence properties. The as-prepared products were characterized by X-ray diffraction, field emission scanning electron microscopy, transmission electron microscopy/high-resolution TEM, energy dispersive X-ray microanalysis, Fourier transform infrared spectrometry and photoluminescence technique. The SmVO4nanosheets had a tetragonal (t-) structure with the thickness of 10–20 nm and the size in the range of 10–12 μm. We found that the amount of ionic liquid, pH value and synthesizing temperature played crucial roles in controlling the structure and morphology of as-prepared samples. Particularly, the amount of ionic liquid [BMIM]Br can effectively control the shape of t-SmVO4nanostructures by adsorption on the (001) plane of the crystals, resulting in their preferential growth along the [100] and [010] directions viahydrogen bond-co-π–π stack interaction. A dissolution-recrystallization process was reasonably proposed to understand the formation mechanism of t-SmVO4nanosheets based on the experimental results. In addition, the photoluminescence spectra reveals that the as-prepared t-SmVO4nanosheets exit red emission related to 4G5/2→6H7/2transition. [ABSTRACT FROM AUTHOR]

Three chromium(III) 1,2,4-diazaphospholide complexes were prepared: 3,5-di- tert-butyl-1,2,4-diazaphospholide chromium(III) dichloride [( η2-3,5- tBu2dp)Cr(THF)2Cl2] ( 1), 3,5-di-phenyl-1,2,4-diazaphospholide chromium(III) dichloride [( η2-3,5-Ph2dp)Cr(THF)2Cl2] ( 2), and 2,6-bis( N-1,2,4-diazaphosphol-1-yl)pyridine chromium(III) trichloride {[2,6-bis( N-1,2,4-diazaphosphol-1-yl)pyridine]CrCl3} ( 3). X-ray diffraction analysis has shown that these six-coordinate complexes each have a pseudo-octahedral configuration. Electron paramagnetic resonance (EPR) spectroscopy data for complex 1 for the paramagnetic S = 3/2 system ( d3 electron configuration) confirm a Cr(III) center in the octahedral coordination environment. The magnetic susceptibility of complex 1 followed the Curie-Weiss law well between 25 and 300 K. The magnetic moment of 1 was found to be close to the spin-only magnetic moment expected for three unpaired electrons (3.87 μB). [ABSTRACT FROM AUTHOR]

One-electron oxidation of the 1,2,4-diazaphospholide anion [3,5-R2dp]− by BiCl3 generated several remarkable paddlewheel dibismuthanes [L2(Bi−Bi)L2] (L = η1,η1-3,5-R2dp, R = tBu, iPr, or Ph) with very short Bi–Bi single bond lengths (2.7964(4)–2.8873(3) Å). [ABSTRACT FROM AUTHOR]

A series of Zn doped TiO2 is prepared via a sol–gel method by changing the concentration of Zn ions and calcination temperature. To investigate the existing states of introduced Zn, the transformation of existing states and the phase transition for the Zn doped TiO2 samples, high resolution transmission electron microscopy (HRTEM), X-ray photoelectron spectroscopy (XPS) and X-ray diffraction (XRD) techniques are applied. The existing states of Zn2+ ions and the transformation of existing states (O–Zn–Cl and ZnTiO3) in Zn doped TiO2 are closely related to the calcination temperature and concentration of introduced Zn ions, as well as the phase transition temperature from anatase to rutile. This work can be helpful for a better realization about the doping mechanism of Zn2+ ions in Zn doped TiO2. [ABSTRACT FROM AUTHOR]

Abstract: A mild hydrothermal process to prepare Ba2SbLnO6 (Ln =Pr, Nd, Sm, Eu) perovskite-type oxides are presented. These perovskites were characterized on the basis of X-ray diffraction (XRD), X-ray photoelectron spectra (XPS), inductively-coupled plasma spectra (ICP) techniques. Primary structure was confirmed using Rietveld method based on XRD data shows that the likely space groups of Ba2SbLnO6 are R-3 for Ln =Pr and Nd and F m-3m for Ln =Sm and Eu, respectively. The measurement of Mössbauer effect of the 37.2keV γ transition of 121Sb indicates that the isomer shift of these perovskites falls in the region of the Sb5+ and reflects some hybridized-orbital behavior in Sb–O bonds. [Copyright &y& Elsevier]

Abstract: In this study, rutile films consisting of rectangular nanorods were facilely deposited on glass substrates from strongly acid solution of TiCl4. The highly ordered array of nanorods was realized in presence of ionic liquid (IL) of [Bmim]Br by following a hydrothermal process. In this process, Degussa P25 nanoparticles served as seeds that were pre-deposited on the substrates to facilitate the array of rutile nanorods. X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), and Raman spectrum were used to characterize the obtained nanorod films. The measurements showed that the nanorods were rectangular with width of 100–200nm and length of more than 1μm, and grew up typically along c-axis to form the arrays against the substrate. The presence of IL was found vital for the formation of rutile nanorods, and the suitable molar ratio of [Bmim]Br to TiCl4 ranged from 500:1 to 1500:1. The excessive [Bmim]Br may hinder the precipitation of rutile particles. [Copyright &y& Elsevier]

Abstract: Cubic MnSe2 and octahedral α-MnSe microcrystals were successfully synthesized through a convenient hydrothermal method with N2H4·H2O as a reductant and SeO2 and MnCl2 as precursors. The crystalline structure, morphology, and chemical composition of the resulting samples were investigated by means of X-ray diffraction (XRD), scanning electron microscopy (SEM), and energy-dispersive spectrometer (EDS), and the results indicated that the cubic MnSe2 has an edge size ranging from 5 to 10μm and the surfaces of these cubes have layer desquamation phenomenon; the α-MnSe has an average size of about 10μm and the most of these microcrystals are in octahedral shapes. It was also found that the phases and morphologies of the manganese selenides can be controlled by changing the content of N2H4·H2O, reaction temperature, and reaction time. The potential formation mechanism of MnSe2 and α-MnSe was discussed. [Copyright &y& Elsevier]

In the present paper, we report a novel hydrothermal synthesis process for the preparation of A-site deficient perovskite-type solid solution in (1−x)BaTiO3·xLa2/3TiO3 (x=0.1–1.0). The synthesized (1−x)BaTiO3·xLa2/3TiO3 have been characterized by powder X-ray diffraction (XRD), ICP elemental analysis, infrared spectroscopy and scanning electron microscopy. The diffractions of samples with x≤0.7 were well indexed as a cubic structure, which is the same as a cubic perovskite-type BaTiO3. In the compositions of x ≥0.8, the crystal structure changes from the cubic to an orthorhombic one. The effect of hydrothermal conditions has also been examined. In this work, it was observed that the optimum ratios of KOH/Ti, La/Ti, and La/Ba were 90, 0.6x and 0.9(1−x), respectively, and the optimum crystallization temperature was 240–260 °C. [Copyright &y& Elsevier]

Abstract: Wurtzite CdSe nanoparticles-assembled microspheres with macropores have been successfully synthesized through a modified hydrothermal method with Cd(NO3)2 and Na2SeO3 as precursors and hydrazine hydrate as a reductant in the presence of 1-n-butyl-3-methylimidazolium bromide ([Bmim]Br). The crystalline structure and morphology of the resulting samples were investigated by means of X-ray powder diffraction (XRD) and scanning electron microscope (SEM). The results indicated that the CdSe microspheres have an average size of about 3 μm and were assembled by CdSe nanoparticles with size ranging from 20 to 40 nm. It was found that the pH and [Bmim]Br have influence on the morphologies of the products, and the potential formation mechanism of CdSe was discussed. [Copyright &y& Elsevier]